Question about 1992 Buick Park Avenue

1 Answer

Rear suspension compressor turns on when without ignition

Rear suspension air compressor turns on when ignition is off is it common electrical problem or someone played with this car before me?
Hynes book says nothing about this circuit, where i can find electrical diagram?

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The compressor turns on when the height level switch closes. This is most likely occuring because the air bags are leaking air.

Posted on Nov 14, 2009

  • orioles6 Sep 18, 2010

    chris868 did ********* have any kids that lived........what a stupid answer .....please keep mouth shut in future

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2008 lincoln navigator check air suspension rear


A technician or mechanic can check this, but the most common problems are:
1) An electrical failure of some part, for example the switch or the relay that activates the compressor, or
2) the compressor itself could have failed.
God bless your efforts.

May 16, 2016 | 2008 Lincoln Navigator

1 Answer

1999 Towncar - Air suspension shocks in good condition and car rides level - no idicator light is on. The car just rides way too stiff. Even the slightest bump jolts the inside (rattles change in ash...


I will check the shop manual, but the module does control ride for stiffness, increased stiffness at higher speeds, etc. If the bags are inflated, then the module cintrols how much air to allow in or out based on inputs to the module. See if you can get one from a salvage yard form a cash for clunkers car.

A dealer can run a test for fault codes in the computer. Call and ask how much for just a scan for fault codes in the air suspension module.

-----------------------------
Vehicle Dynamic Suspension The vehicle dynamic suspension consists of the following components:
  • Rear air suspension control (RAS) module (5A919)
  • Snorkel
  • Drier
  • Air compressor (5319)
  • Air suspension switch (5K761)
  • Solenoid valve (5311)
  • Air spring (5560)
  • Air suspension height sensor (5359)
  • Air line
----------------------------------------------------------------------------
Rear Air Suspension Control Module
A microprocessor controls the air suspension system. The microprocessor and its supporting hardware are contained in the rear air suspension control module. The rear air suspension control module responds to signals from various sensors in the vehicle to maintain the programmed ride height while the vehicle is either moving or stopped. The rear air suspension control module accomplishes this by opening and closing solenoid valves to control the amount of air in the air spring(s). The rear air suspension control module turns on the compressor by applying voltage through the compressor relay to inflate the air spring(s) and raise the vehicle. The rear air suspension control module opens the vent solenoid to lower the vehicle by releasing air from the air spring(s) in response to signal inputs from the air suspension height sensor(s).
Air Suspension Switch
sxg~us~en~file=ani_caut.gif~gen~ref.gif CAUTION: The air suspension switch must be turned to the OFF position when the vehicle is hoisted, jacked, towed, jump started, or raised off the ground, to avoid unnecessary operation of the system and possible damage to the air suspension system components.
The air suspension switch provides a signal to the rear air suspension control module in the ON position to activate the system to maintain the programmed vehicle height.
Air Compressor
NOTE: The compressor contains a thermal overload circuit breaker. The circuit breaker automatically resets after a cool down period and after being tripped by excessive compressor motor heat.
The air compressor assembly consists of the compressor pump, electric motor and vent solenoid (must be installed as an assembly).
Air Suspension Height Sensor
The air suspension height sensor sends signals to the air suspension control module. There are three possible conditions that the air suspension control module interprets from the signals of the air suspension height sensors. The conditions are trim height, below trim height, or above trim height.
Solenoid Valve, Air Spring
sxg~us~en~file=ani_caut.gif~gen~ref.gif WARNING: Never rotate an air spring solenoid valve to the release slot in the air spring end cap fitting until all pressurized air has escaped from the air spring to prevent vehicle damage or personal injury.
The air spring solenoid valve allows air to enter and exit the rear air springs during height adjustment operations. The air spring solenoid valve is electrically operated and controlled by the air suspension control module.
Steering Sensor
The steering sensor provides the steering rate and position to the air suspension control module to avoid overcompensation of the air suspension during turns.
Inspection and Verification
  1. Verify the customer concern.
  1. NOTE: If the door ajar indicator is illuminated, repair the door ajar indicator. For additional information, refer to Section 413-09 .
    Visually inspect for obvious signs of mechanical and electrical damage.


Visual Inspection Chart Mechanical Electrical
  • Restricted suspension movement
  • Excessive vehicle load
  • Cut, severed or crimped air line(s)
  • Incorrectly mounted, damaged or disconnected height sensor
  • Damaged air spring(s)
  • Central junction box (CJB) Fuse:
    • 8 (10A)
    • 17 (10A)
  • Battery junction box (BJB) Fuse 12 (30A)
  • Loose or corroded connectors
  • Air suspension switch
  • Damaged air spring solenoid(s)


  1. If the concern remains after the inspection, connect New Generation STAR (NGS) Tester to the data link connector (DLC) located beneath the instrument panel and select the vehicle to be tested from the NGS Tester menu. If NGS Tester does not communicate with the vehicle:
    • check that the program card is properly installed.
    • check the connections to the vehicle.
    • check the ignition switch position.
  1. If the NGS still does not communicate with the vehicle, refer to the New Generation STAR Tester manual.
  1. Carry out the DATA LINK DIAGNOSTIC TEST. If NGS Tester responds with:
    • CKT914, CKT915 or CKT70 = ALL ECUS NO RESP/NOT EQUIP. Refer to Section 418-00 .
    • NO RESP/NOT EQUIP for rear air suspension control module, go to Pinpoint Test A.
    • SYSTEM PASSED, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and perform self-test diagnostics for the rear air suspension control module.
  1. If the DTCs retrieved are related to the concern, go to Rear Air Suspension Control Module Diagnostic Trouble Code (DTC) Index to continue diagnostics.
  1. If no DTCs related to the concern are retrieved, proceed to Symptom Chart to continue diagnostics.
Rear Air Suspension Control Module Diagnostic Trouble Code (DTC) Index
NOTE: If rear air suspension control module C251 is disconnected before rear air suspension control module C250, DTCs C1830, C1770, C1790 and C1795 will be retrieved and must be cleared before an accurate list of continuous DTCs can be retrieved. The DTCs C1441 and C1442 will only be retrieved when running the electronic variable orifice (EVO) functional test on NGS Tester. The DTC C1897 will only be retrieved once per ignition switch cycle.

-----------------------------------------------------------------------------------
Module —Air Suspension Control Removal
sxg~us~en~file=ani_caut.gif~gen~ref.gif WARNING: Before performing maintenance on any air suspension components, disconnect the power to the system by turning off the air suspension switch located on the LH side of the luggage compartment to prevent vehicle damage or personal injury.
sxg~us~en~file=ani_caut.gif~gen~ref.gif CAUTION: Electronic modules are sensitive to static electrical charges. If exposed to these charges, damage may result.
  1. Turn the air suspension switch off.
  1. Disconnect the battery ground cable (14301).
  1. Pull out the lower instrument panel insulator.
    1. Remove the pushpins.
    1. Pull out the lower instrument panel insulator.
  1. Remove the lower instrument panel insulator.
    1. Disconnect the power point.
    1. Disconnect the courtesy lamp.
    1. Remove the lower instrument panel insulator.
  1. Remove the rear air suspension control module.
    1. Remove the screws.
    1. Disconnect the electrical connectors.
    1. Remove the rear air suspension control module.
Installation
  1. NOTE: When the battery is disconnected and reconnected, some abnormal drive symptoms may occur while the vehicle relearns its adaptive strategy. The vehicle may need to be driven 16 km (10 mi) or more to relearn the strategy.
    To install, reverse the removal procedure.

Jan 20, 2010 | Lincoln Town Car Cars & Trucks

1 Answer

I have a 1994 lincoln continental car. Hoe do I replace the suspention drier?


why do you want to replace it? As air is exhausted through it, it dires it out for the next use. it's part of compressor assembly.

1996 cont'l The air suspension system includes the following major components:
  • Air compressor to supply air to the air springs (part of front spring and shock and rear spring and shock absorber assemblies
  • Front spring and shock (3C098) and rear spring and shock absorber (5A965) at each corner of the vehicle
  • Four linear air suspension height sensors (5359): two rear and two front height sensors to maintain the vehicle at the proper ride height; only LH rear height sensor is used for air suspension.
  • Dual-mode front spring and shock and rear shock absorber assemblies with internal actuator.
All system functions are controlled by vehicle dynamics control module (5A919). This control module receives inputs from several different sources. These inputs include:
  • vehicle speed via multiplex communication network
  • ignition switch position
  • door position via multiplex communication network
  • height sensor position
  • air suspension service switch
  • engine rpm via multiplex communication network
  • ride and steering personality settings via multiplex communications network
Communications monitor system operation and allow diagnosis of any concerns that may develop in the system. System monitoring for the driver's use is provided through the instrument panel mounted message center indicator (10D898).
  • Diagnosis communication for the service technician is provided through the data link connector (14489) (DLC) under the instrument panel and Rotunda New Generation Star (NGS) Tester 007-00500 or equivalent.
The message center indicator will display AIR LEVELING DISABLED or CHECK RIDE CONTROL if the suspension system is not turned on or the vehicle dynamics control module detects a concern. If air leveling system disabled is displayed, check that air suspension service switch is in the ON position.
----------------------------------------------------------
Solenoid Valve Vent The vent solenoid valve operates as follows:
  • The vent solenoid valve allows air to escape from the system during venting corrections.
  • The valve is located in the air compressor cylinder head and shares a common electrical connector with the motor.
  • The valve is enclosed in the cylinder head casting, which forms an integral valve housing that allows the valve tip to enter the pressurized side of the system.
  • Air leakage past the valve tip is prevented by an O-ring seal.
  • The vent solenoid valve opens when a corner of the vehicle is high and the vehicle dynamics control module (5A919) determines lowering is required.
  • When the vent solenoid valve is opened, it provides an escape route for pressurized air.
  • However, the vehicle will not lower unless the air spring solenoid valves (5311) are also opened to allow air to leave the springs.
  • Lowering the vehicle corners requires the vehicle dynamics control module to open two solenoid valves, the vent and one air spring solenoid.
  • Air is exhausted from the spring and vents through the compressor air drier (5346).
---------------------------------------------------------------------------------------------
Section 04-05: Suspension, Computer Controlled 1996 Continental Workshop Manual
REMOVAL AND INSTALLATION Air Compressor and Drier Assembly Removal
  1. Turn air suspension service switch OFF.
  1. Disconnect electrical connector located on the air compressor.
  1. Disconnect two air lines from compressor air drier.
  1. Remove three fasteners retaining air compressor and drier assembly to radiator support, frame rail and fender apron.

Dec 22, 2009 | 1994 Lincoln Continental

3 Answers

The rear suspension air bags no work


start here

The air suspension system is designed to improve ride, handling and general vehicle performance for static, on-road and off-road driving condition:
  • Ride is improved by using an air type spring (the soft ride is inherent).
  • Handling is improved by maintaining constant vehicle attitude.
The system consists of unique rear air springs, air compressor, air lines, air spring solenoids, height sensor, air suspension control module, attachments and associated signals derived from both driver and road inputs. With these components and signals, the air suspension control module commands changes in vehicle height that are necessary for the load leveling features.
The load leveling feature rear air suspension (RAS) systems shall automatically make adjustments in vehicle height so that the vehicle is always at trim height and constant front-to-rear vehicle attitudes are maintained over the expected load range of the vehicle. Adjustments in height that are necessary to correct height differences between the vehicle's left and right sides for RAS system shall be restricted to what can be reliably achieved with one air suspension height sensor.
The system uses one air suspension height sensor, a steering sensor, generic electronic module (GEM) transfer case inputs, and other vehicle sensors to measure driver and road inputs. The system changes vehicle height using an air compressor, two air lines, and the use of an air spring with an air spring solenoid.
The air suspension system holds vehicle height when the rear hatch or any door is opened. The system stores rear vehicle height the moment any open door is detected. The system then maintains this height regardless of the addition or removal of a load. The system will return to its commanded height when all doors are closed and the vehicle speed exceeds 16 km/h (10 mph).
Air Suspension Switch
The air suspension switch is located behind the RH kick panel on a mounting bracket. The switch interrupts power to the air suspension control module.
The air suspension switch supplies a signal to the air suspension control module. Without the air suspension control module receiving this signal the load leveling system is inoperative and will not react when rear of the vehicle is raised or lowered. If the air suspension system is disabled by turning off air suspension switch, a "CHECK SUSP" will appear in the RH corner of the instrument cluster with the ignition in the run position.
Air Compressor
The RAS air compressor:
  • Is not interchangeable with four wheel air suspension (4WAS) compressor.
  • Consists of the compressor and vent solenoid; neither are replaceable as individual items.
  • Is mounted in the engine compartment between the washer fluid bottle and headlamp (RH front corner).
  • Is a single cylinder electric motor driven unit that provides pressurized air as required.
  • Is powered by a solid state relay, controlled by the air suspension control module.
  • Passes pressurized air through the compressor air drier that contains silica gel (a drying agent). Moisture is then removed from the compressor air drier when vented air passes out of the system during vent operation.
  • Air drier has a single port and is not interchangeable with 4WAS compressor air drier.
  • Air drier may be replaced separately.
  • Incorporates a snorkle that may be replaced separately.
The vent solenoid:
  • Allows air to escape from the system during venting actions.
  • Is located in the air compressor cylinder head.
  • Has a 160 psi internal relief valve.
  • Shares a common electrical connector with the air compressor motor.
  • Is enclosed in the cylinder head casting, which forms an integral valve housing that allows the valve tip to enter the pressurized side of the system.
  • Has an O-ring seal that prevents air leakage past the valve tip.
  • Opens when the air suspension control module determines lowering is required.
  • Provides an escape route for pressurized air that opens when system pressures exceed safe operating levels.
  • Is replaced with the air compressor as a unit.
Air Spring
RAS vehicles use air springs in the rear. The air springs provide a varying spring rate proportional to the systems air pressure and volume. The air suspension system regulates the air pressure in each air spring by compressing and venting the system air. Increasing air pressure (compressing) raises the rear of the vehicle while decreasing air pressure (venting) lowers the rear of the vehicle. Vehicle height is maintained by the addition and removal of air in each air spring through an air spring solenoid installed in the upper spring cap and energized through the air suspension control module.
The air springs are mounted between the axle spring seats and the frame upper spring seats.
The two air springs replace the conventional rear coil springs.
Air Suspension Height Sensor
When the air suspension height sensor indicates that the rear of the vehicle is lower than trim under normal driving conditions, the air compressor will turn on and pump compressed air to the air springs. When the sensor indicates that the rear of the vehicle is raised above trim under normal driving conditions, this will cause the air to be vented from the air springs to lower the vehicle back to its trim height level.
One air suspension height sensor is mounted on the vehicle. The air suspension height sensor sends a voltage signal to the air suspension control module. The output ranges from approximately 4.75 volts at minimum height (when the vehicle is low or in full jounce), to 0.25 volts at maximum height (when the vehicle is high or in full rebound). The air suspension height sensor has a useable range of 80 mm (3 in) compared to total suspension travel of 200-250 mm (8 to 10 in) at the wheel. Therefore, the air suspension height sensor is mounted to the suspension at a point where full rear suspension travel at the wheel is relative to 80 mm of travel at the air suspension height sensor. The air suspension height sensor is attached between the No. 5 frame crossmember (upper socket) and the panhard rod (lower socket). Replace the air suspension height sensor as a unit.
Compressor Relay
The compressor relay is energized by the air suspension control module to allow high current to flow from the battery to the compressor motor.
  • A solid state relay is used in the air suspension system for air compressor control. The relay incorporates a custom power metal oxide semi-conductor field effect transistor (MOSFET) and ceramic hybrid circuitry. The relay switches high current loads in response to low power signals and is controlled by the logic of the air suspension control module.
Air Suspension Control Module
NOTE: The 4WAS air suspension control module is used for the RAS system. The internal processor recognizes external circuitry to determine if it is installed in a 4WAS or a RAS equipped vehicle.
NOTE: The air suspension control module is calibrated with information from the air suspension height sensor. A new or exchanged air suspension control module requires a ride height adjustment calibration process to be performed.
The air suspension control module controls the air compressor motor (through a solid state relay), and the air spring solenoids. The air suspension control module also provides power to the air suspension height sensor. The air suspension control module controls vehicle height adjustments by monitoring the air suspension height sensor, vehicle speed, a steering sensor, acceleration input, the door ajar signal, transfer case signals, and the brake pedal position (BPP) switch. The air suspension control module also conducts all fail-safe and diagnostic strategies and contains self-test and communication software for testing of the vehicle and related components.
The air suspension control module is mounted in the passenger compartment inside the instrument panel above the radio and temperature controls.
The air suspension control module monitors and controls the air suspension system through a 32-pin two-way connector. The air suspension control module is keyed so that the air suspension control module cannot be plugged into an incorrect harness. There are two sides of the harness connection to the air suspension control module. Each is uniquely colored and keyed to prevent reversing the connections.
Air Suspension Diagnostic Connector
The air suspension diagnostic connector is used to aid the technician in diagnosing the air suspension system. It is also used to vent the system of compressed air when air suspension system components need to be repaired or replaced. The air suspension diagnostic connector is located under steering column.

Oct 02, 2009 | 1998 Ford Expedition

1 Answer

2002 linncoln towncar where is the air supension compressor relay switch,please.


Air suspension needs compressed air for the control of Air Springs (Air Spring is a cylinder like thing which goes up and down when air is pumped in and out of it). For pumping in and out the air, air compressor needs to be switched ON/OFF. Compressor relay connects and disconnects the compressor motor from the power supply ( battery). ----------------- air ride suspension compressor located under the air filter box . ---------------- the Air compressor clutch relay location
is fitted to the left hand inner wing (when viewed from the the driving seat).
-------------------
the compresser is located on the left hand side of the car under the hood.
once you open the hood remove the air cleaner housing and windshield washer resivor.
there is a panel that you lift up under both of thoese that is where the compresser is located
-------------
  1. The air suspension uses a small, separate air compressor under the driver's side left fenderwell, with air lines running to the air bags. On the top of each air bag is a electrical valve. This is a relief valve that allows air to be exhausted when activated, and which senses the amount of air pressure within the air bag to keep both sides equal. These valves are operated via a leveling sensor that is attached to the body of the car and to the rear axle by a movable arm. When the rear of the car drops due to increased load, the arm is pushed up. When the arm is pushed up, it turns on the air compressor and fills the air bags to level the car. When the load is removed and the arm moves down, indicating that the back of the car has risen, the sensor opens the valve on the air bags and allows air to escape, lowering the car.
  2. If the back of the car is low, indicating that the air suspension is not working, and the air suspension light is on, check the fuse first. If the fuse is all right, check the air suspension switch in the trunk and make sure it is on. This switch is used when the car is in for service. Always turn off the switch before lifting the car, because the sensor will think the car is rising and keep the air bag valves open, ruining the rear air suspension.
  3. Turn the ignition key with the engine off. Listen for the compressor to come on while pushing down on the rear bumper. If it does not come on, test the switch terminals for power, using a circuit tester. If one terminal has power and the other does not, replace the switch. If there is power, turn the switch to the off position, raise the vehicle and place it on jack stands in the rear. Inspect the leveling switch on the axle, making sure it is not bent and is connected. Use an ohmmeter for this test. Pull the electrical connector off the switch. Loosen the arm of the switch from the axle. Test the switch with the ohmmeter by checking across both terminals while slowly moving the arm. There should be no continuity with the arm down. As the arm is raised, there should be continuity. If not, replace the switch. If there was continuity, connect the arm and the electrical connector.
  4. Put a floor jack under the axle and raise the axle to the point where it is just beginning to lift the car off the jack stand. Turn on the ignition. Turn the air suspension switch to the "on" position. Use the circuit tester to check for power at the leveling switch. If there is power, turn the air suspension switch to "off" and lower the car. Access the air compressor in the front, under the hood, and check the electrical connector for power. If there is power, check for a good ground. If both are good, replace the compressor. If the compressor works and the car does not rise in the back, replace the air bags.


Sep 11, 2009 | 2002 Lincoln Town Car

2 Answers

Can any one tell me were how i can find the automatic level control on my 1994 town car


Description and Operation The rear air suspension:
  • Is an air-operated, microprocessor-controlled, suspension system.
  • Replaces the conventional rear coil spring suspension.
  • Provides low spring rates for improved ride and automatic rear load leveling.
  • Is standard equipment on the Town Car.
  • Is available as optional equipment on Crown Victoria and Grand Marquis.
The rear air suspension system has the following features:
  • The system is operational with the ignition switch in the RUN position.
  • Automatic rear load leveling has limited operation for one hour after ignition switch is turned to OFF.
  • The air suspension switch, located on the right side of the luggage compartment, must be turned OFF when the vehicle is on a hoist, being towed or jump started.
  • The Air Suspension warning indicator is located in the instrument panel, to the right of the speedometer.
    • The warning indicator flashes five times and then stays on when service switch is turned off or a system malfunction is detected.
  • The rear leveling system operates by adding or removing air in the springs to maintain the level of the vehicle at a predetermined rear suspension D ride height dimension, and is controlled by a control module (5A919) .
  • The rear air suspension control module also controls the electronic variable orifice (EVO) steering.
  • Refer to Section 11-02 for Description of the EVO steering system.
  • Air required for leveling the vehicle is distributed from the air compressor to the rear air springs by a nylon air line which runs from the compressor air dryer (5346) through a Y-fitting to each individual air spring.


Suspension, Computer Controlled—Town Car

c441c13.gif
Item Part Number Description 1 9C392 Compressor Relay Power Junction Block 2 5A897 Air Line (Attached to Brake/Fuel Bundle) 3 5319 Air Compressor With Regenerative Air Dryer and Vent Solenoid 4 5A897 Air Line to Compressor 5 5K761 Air Suspension Service Switch 6 14489 Data Link Connector 7 — Quick Connect 8 — To LH Air Spring 9 — From Compressor 10 — Y-Fitting (Part of 5A911) 11 — To RH Air Spring 12 5A908 Heat Shield 13 5A966 Spring Retainer Clip 14 5560 Rear Spring 15 5359 RearAir Suspension Height Sensor 16 5A919 Control Module 17 14018 Air Spring Solenoid

Control Module Power and Ground The control module (5A919) has the following features:
  • Power is provided by Circuit 418 and is controlled by the air suspension switch.
    • The air suspension switch is powered through a 15 amp fuse in Circuit 296 in Town Car.
    • AIR SUSPN PUMP (30A MAXI) fuse provides this power through Circuit 414 in the Crown Victoria/Grand Marquis.
  • Control module ground is provided through control module wire harness Pins 6 and 21, to the RH inner quarter panel sheet metal, near the control module .
---------------------------------
Weight Added When weight is added to the vehicle:
  • The air suspension height sensor (5359) length is reduced from trim length, sending a "rear is low" signal to the control module (5A919).
  • The control module then turns the compressor on by grounding the compressor relay control Circuit 420. This restores the rear of the vehicle to trim position.
    • Battery voltage is provided to the relay coil by Circuit 414.
  • The control module opens the spring solenoid valves (5311) by switching Circuits 416 and 429 to ground. This allows pressurized air to enter the springs.
    • Battery voltage is provided to the air spring solenoid valves by Circuit 414.
  • Compressed air flows from the compressor, through the compressor air dryer (5346) airlines and spring solenoid valves into the rear springs (5560).
  • As the rear springs raise the rear body height, the air suspension height sensor increases in length until the preset trim height is reached.
  • The control module then turns off the compressor (through the relay) and closes the air spring solenoid valves.
----------------------------------------------------------------------
Weight Removed When weight is removed:
  • The air suspension height sensor (5359) length is increased from the trim length, sending a "rear is high" signal to the control module (5A919).
  • The control module then opens the vent solenoid valve (located in the compressor assembly) by switching Circuit 421 to ground and opens the solenoid valves (5311) by switching Circuits 416 and 429 to ground. This restores the rear of the vehicle to trim position.
  • Compressed air flows from rear springs (5560), through the air spring solenoid valves, air lines, compressor air dryer (5346), and out the vent solenoid valve.
  • As the body lowers, the air suspension height sensor length decreases until the preset trim height is reached.
  • The control module then closes the vent and solenoid valves.
-----------------------------------------
Control module operates as follows:
  • In general the control module uses a 45-second averaging interval to determine when compress and vent operations are needed.
  • However, door courtesy lamp switch (13713) inputs can override the 45-second averaging interval so compress and vent operations can begin immediately, if needed.
  • The 45-second averaging interval is used to keep the control module from making unneeded corrections.
  • When a vehicle at the correct rear trim height hits a bump, the air suspension height sensor output will read low and high in addition to trim until the oscillations die out.
  • If the control module were to correct for these "bump induced readings", system duty cycle would increase unnecessarily.
  • The 45-second averaging interval not only eliminates corrections due to bumps, but also eliminates unneeded corrections resulting from braking, accelerating, and turning. The control module tabulates the air suspension height sensor readings, and does not begin a compress or vent operation until the air suspension height sensor (5359) reads low or high for 45 seconds consistently.
  • There are more restrictions on vent operations than there are on compress operations.
  • To eliminate the chance of catching a door on a curb as the vehicle vents down, the control module will not allow any venting to occur when a door is open.
  • The control module does not allow any vent operations for the first 45 seconds after the ignition switch (11572) has been turned to RUN.
    • Even if a vehicle is extremely high in the rear, DO NOT expect it to vent until the ignition switch has been turned to RUN for 45 seconds.

Jun 24, 2009 | 1994 Lincoln Town Car

4 Answers

Forgot toi turn the air suspension off when


Remove battery, remove windshield washer bottle, remove air compressor and disconnect both air lines from the compressor dryer. Make sure compressor electrical wiring is plugged in, install battery, turn suspension switch to ON, turn ignition switch to the ON position, close all door and the compressor should come on and completely lower the whole truck. Once the truck is completely down, turn the ignition OFF, remove battery and connect both air lines. Install battery ensure electrical wiring is plugged in, turn ignition switch to ON, the compressor should come on and raise the vehicle to the correct ride height.

Jun 14, 2009 | 2001 Lincoln Navigator

3 Answers

Rear air bag suspension failure 1998 Ford EXP E.B. 2x2


this will get you started. report back on progress and we'll go from there. There is a diagnostic test that will provide codes I think. I will look.

The system consists of unique rear air springs, air compressor, air lines, air spring solenoids, height sensor, air suspension control module, attachments and associated signals derived from both driver and road inputs. With these components and signals, the air suspension control module commands changes in vehicle height that are necessary for the load leveling features.
The load leveling feature rear air suspension (RAS) systems shall automatically make adjustments in vehicle height so that the vehicle is always at trim height and constant front-to-rear vehicle attitudes are maintained over the expected load range of the vehicle. Adjustments in height that are necessary to correct height differences between the vehicle's left and right sides for RAS system shall be restricted to what can be reliably achieved with one air suspension height sensor.
The system uses one air suspension height sensor, a steering sensor, generic electronic module (GEM) transfer case inputs, and other vehicle sensors to measure driver and road inputs. The system changes vehicle height using an air compressor, two air lines, and the use of an air spring with an air spring solenoid.
The air suspension system holds vehicle height when the rear hatch or any door is opened. The system stores rear vehicle height the moment any open door is detected. The system then maintains this height regardless of the addition or removal of a load. The system will return to its commanded height when all doors are closed and the vehicle speed exceeds 16 km/h (10 mph).
Air Suspension Switch
The air suspension switch is located behind the RH kick panel on a mounting bracket. The switch interrupts power to the air suspension control module.
The air suspension switch supplies a signal to the air suspension control module. Without the air suspension control module receiving this signal the load leveling system is inoperative and will not react when rear of the vehicle is raised or lowered. If the air suspension system is disabled by turning off air suspension switch, a "CHECK SUSP" will appear in the RH corner of the instrument cluster with the ignition in the run position.
Air Compressor
The RAS air compressor:
  • Is not interchangeable with four wheel air suspension (4WAS) compressor.
  • Consists of the compressor and vent solenoid; neither are replaceable as individual items.
  • Is mounted in the engine compartment between the washer fluid bottle and headlamp (RH front corner).
  • Is a single cylinder electric motor driven unit that provides pressurized air as required.
  • Is powered by a solid state relay, controlled by the air suspension control module.
  • Passes pressurized air through the compressor air drier that contains silica gel (a drying agent). Moisture is then removed from the compressor air drier when vented air passes out of the system during vent operation.
  • Air drier has a single port and is not interchangeable with 4WAS compressor air drier.
  • Air drier may be replaced separately.
  • Incorporates a snorkle that may be replaced separately.
The vent solenoid:
  • Allows air to escape from the system during venting actions.
  • Is located in the air compressor cylinder head.
  • Has a 160 psi internal relief valve.
  • Shares a common electrical connector with the air compressor motor.
  • Is enclosed in the cylinder head casting, which forms an integral valve housing that allows the valve tip to enter the pressurized side of the system.
  • Has an O-ring seal that prevents air leakage past the valve tip.
  • Opens when the air suspension control module determines lowering is required.
  • Provides an escape route for pressurized air that opens when system pressures exceed safe operating levels.
  • Is replaced with the air compressor as a unit.
Air Spring
RAS vehicles use air springs in the rear. The air springs provide a varying spring rate proportional to the systems air pressure and volume. The air suspension system regulates the air pressure in each air spring by compressing and venting the system air. Increasing air pressure (compressing) raises the rear of the vehicle while decreasing air pressure (venting) lowers the rear of the vehicle. Vehicle height is maintained by the addition and removal of air in each air spring through an air spring solenoid installed in the upper spring cap and energized through the air suspension control module.
The air springs are mounted between the axle spring seats and the frame upper spring seats.
The two air springs replace the conventional rear coil springs.
Air Suspension Height Sensor
When the air suspension height sensor indicates that the rear of the vehicle is lower than trim under normal driving conditions, the air compressor will turn on and pump compressed air to the air springs. When the sensor indicates that the rear of the vehicle is raised above trim under normal driving conditions, this will cause the air to be vented from the air springs to lower the vehicle back to its trim height level.
One air suspension height sensor is mounted on the vehicle. The air suspension height sensor sends a voltage signal to the air suspension control module. The output ranges from approximately 4.75 volts at minimum height (when the vehicle is low or in full jounce), to 0.25 volts at maximum height (when the vehicle is high or in full rebound). The air suspension height sensor has a useable range of 80 mm (3 in) compared to total suspension travel of 200-250 mm (8 to 10 in) at the wheel. Therefore, the air suspension height sensor is mounted to the suspension at a point where full rear suspension travel at the wheel is relative to 80 mm of travel at the air suspension height sensor. The air suspension height sensor is attached between the No. 5 frame crossmember (upper socket) and the panhard rod (lower socket). Replace the air suspension height sensor as a unit.
Compressor Relay
The compressor relay is energized by the air suspension control module to allow high current to flow from the battery to the compressor motor.
  • A solid state relay is used in the air suspension system for air compressor control. The relay incorporates a custom power metal oxide semi-conductor field effect transistor (MOSFET) and ceramic hybrid circuitry. The relay switches high current loads in response to low power signals and is controlled by the logic of the air suspension control module.
Air Suspension Control Module
NOTE: The 4WAS air suspension control module is used for the RAS system. The internal processor recognizes external circuitry to determine if it is installed in a 4WAS or a RAS equipped vehicle.
NOTE: The air suspension control module is calibrated with information from the air suspension height sensor. A new or exchanged air suspension control module requires a ride height adjustment calibration process to be performed.
The air suspension control module controls the air compressor motor (through a solid state relay), and the air spring solenoids. The air suspension control module also provides power to the air suspension height sensor. The air suspension control module controls vehicle height adjustments by monitoring the air suspension height sensor, vehicle speed, a steering sensor, acceleration input, the door ajar signal, transfer case signals, and the brake pedal position (BPP) switch. The air suspension control module also conducts all fail-safe and diagnostic strategies and contains self-test and communication software for testing of the vehicle and related components.
The air suspension control module is mounted in the passenger compartment inside the instrument panel above the radio and temperature controls.
The air suspension control module monitors and controls the air suspension system through a 32-pin two-way connector. The air suspension control module is keyed so that the air suspension control module cannot be plugged into an incorrect harness. There are two sides of the harness connection to the air suspension control module. Each is uniquely colored and keyed to prevent reversing the connections.
Solenoid Valve, Air Spring
swj~us~en~file=ani_caut.gif~gen~ref.gif WARNING: Never rotate an air spring solenoid valve to the release slot in the end cap fitting until all pressurized air has escaped from the spring to prevent damage or injury.
The air spring solenoid:
  • allows air to enter and exit the air spring during leveling operations.
  • is electrically operated and controlled by the air suspension control module.
Air Suspension Diagnostic Connector
The air suspension diagnostic connector is used to aid the technician in diagnosing the air suspension system. It is also used to vent the system of compressed air when air suspension system components need to be repaired or replaced. The air suspension diagnostic connector is located under steering column.

Jun 01, 2009 | 1998 Ford Expedition

3 Answers

Rear air suspension compressor not engaging.


what year? here's 2003 rear air only info, not 4 wheel air.

you have a fuse panel in truck and 1 under hood.




Visual Inspection Chart Mechanical Electrical
  • Restricted suspension movement
  • Excessive vehicle load
  • Cut, severed or crimped air line(s)
  • Unmounted height sensor
  • Damaged air spring(s)
  • Open fuses:
    • Central junction box (CJB) Fuse 4 (15A), 6 (5A) and 20 (5A)
    • Battery junction box (BJB) Fuse 109 (50A)
  • Loose, corroded or disconnected connectors
  • Air suspension switch is in the OFF position
  • Damaged solenoid valve(s)

  • compressor is inoperative
  • BJB Fuse 109 (50A).
  • Air compressor assembly.
  • Circuitry.
  • Air suspension relay.
  • Go To Pinpoint Test P .



----------------------------------------------------------------------------

The system consists of unique rear air springs, the air compressor, air lines, air spring solenoids, height sensor, air suspension control module, attachments and associated signals derived from both driver and road inputs. With these components and signals, the air suspension control module commands changes in vehicle height that are necessary for the load leveling features.
The load leveling feature rear air suspension (RAS) systems shall automatically make adjustments in vehicle height so that the vehicle is always at trim height and constant front-to-rear vehicle attitudes are maintained over the expected load range of the vehicle. Adjustments in height that are necessary to correct height differences between the vehicle's left and right sides for the RAS system shall be restricted to what can be reliably achieved with one air suspension height sensor.
The system uses one air suspension height sensor, a steering sensor, generic electronic module (GEM) and other vehicle sensors to measure driver and road inputs. The system changes vehicle height using an air compressor, two air lines and the use of air springs with air spring solenoids.

Air Suspension Switch
The air suspension switch supplies power to the air suspension control module. Without the air suspension control module receiving this power, the load leveling system is inoperative and will not react when the rear of the vehicle is raised or lowered. If the air suspension system is disabled by turning off the air suspension switch, a "CHECK SUSP" will appear in the RH corner of the instrument cluster with the ignition in the run position.
Air Compressor
The RAS air compressor:
  • consists of the compressor and vent solenoid; neither are replaceable as individual items.
  • is a single cylinder electric motor driven unit that provides pressurized air as required.
  • is powered by a solid state relay which is controlled by the air suspension control module.
  • passes pressurized air through the compressor air drier that contains silica gel (a drying agent). Moisture is then removed from the compressor air drier when vented air passes out of the system during vent operation.
  • air drier has a single port.
  • air drier may be replaced separately.
  • incorporates a snorkel that may be replaced separately.
The vent solenoid:
  • allows air to escape from the system during venting actions.
  • is part of the air compressor cylinder head.
  • has a 1,103 kPa (160 psi) internal relief valve.
  • shares a common electrical connector with the air compressor motor.
  • is enclosed in the cylinder head casting, which forms an integral valve housing that allows the valve tip to enter the pressurized side of the system.
  • has an O-ring seal that prevents air leakage past the valve tip.
  • opens when the air suspension control module determines lowering is required.
  • provides an escape route for pressurized air that opens when system pressures exceed safe operating levels.
  • is replaced with the air compressor as a unit.
Air Spring
RAS vehicles use air springs in the rear. The air springs provide a varying spring rate proportional to the systems air pressure and volume. The air suspension system regulates the air pressure in each air spring by compressing and venting the system air. Increasing air pressure (compressing) raises the rear of the vehicle while decreasing air pressure (venting) lowers the rear of the vehicle. Vehicle height is maintained by the addition and removal of air in each air spring through an air spring solenoid installed in the upper spring cap and energized through the air suspension control module.
The two air springs support the conventional rear leaf coil springs.
Air Suspension Height Sensor
One air suspension height sensor is mounted on the vehicle. The air suspension height sensor sends a voltage signal to the air suspension control module. The output ranges from approximately 4.75 volts at minimum height (when the vehicle is low or in full jounce), to 0.25 volts at maximum height (when the vehicle is high or in full rebound). The air suspension height sensor has a useable range of 80 mm (3.2 in) compared to total suspension travel of 200-250 mm (8 to 10 in) at the wheel. Therefore, the air suspension height sensor is mounted to the suspension at a point where full rear suspension travel at the wheel is relative to 80 mm (3.2 in) of travel at the air suspension height sensor. The air suspension height sensor is attached between the No. 5 frame crossmember (upper socket) and the panhard rod (lower socket).
When the air suspension height sensor indicates that the rear of the vehicle is lower than trim under normal driving conditions, the air compressor will turn on and pump compressed air to the air springs. When the sensor indicates that the rear of the vehicle is raised above trim under normal driving conditions, this will cause the air to be vented from the air springs to lower the vehicle back to its trim height level.
Compressor Relay
The compressor relay is energized by the air suspension control module to allow high current to flow from the battery to the compressor motor.
  • A solid state relay is used in the air suspension system for air compressor control. The relay incorporates a custom power metal oxide semi-conductor field effect transistor (MOSFET) and ceramic hybrid circuitry. The relay switches high current loads in response to low power signals and is controlled by the logic of the air suspension control module.
Air Suspension Control Module
NOTE: The 4WAS air suspension control module is used for the RAS system. The internal processor recognizes external circuitry to determine if it is installed in a 4WAS or a RAS equipped vehicle.
NOTE: The air suspension control module is calibrated with information from the air suspension height sensor. A new or exchanged air suspension control module requires a ride height adjustment calibration process to be performed.
The air suspension control module controls the air compressor motor (through a solid state relay), and the air spring solenoids. The air suspension control module also provides power to the air suspension height sensor. The air suspension control module controls vehicle height adjustments by monitoring the air suspension height sensor, vehicle speed, a steering sensor, acceleration input, the door ajar signal, transfer case signals, and the brake pedal position (BPP) switch. The air suspension control module also conducts all fail-safe and diagnostic strategies and contains self-test and communication software for testing the vehicle and related components.
The air suspension control module monitors and controls the air suspension system through a 32-pin two-way connector. The air suspension control module is keyed so that the air suspension control module cannot be plugged into an incorrect harness. There are two sides of the harness connection to the air suspension control module. Each is uniquely colored and keyed to prevent reversing the connections.
Solenoid Valve, Air Spring
s2j~us~en~file=ani_caut.gif~gen~ref.gif WARNING: Never rotate an air spring solenoid valve to the release slot in the end cap fitting until all pressurized air has escaped from the spring to prevent damage or injury.
The air spring solenoid:
  • allows air to enter and exit the air spring during leveling operations.
  • is electrically operated and controlled by the air suspension control module.
  • is only installed as a unit.

Apr 18, 2009 | 2003 Lincoln Navigator

2 Answers

Where are the leveling sensors located on a 2003 Navigator?


There is one at each wheel. here is some info

Vehicle Dynamic Suspension The four wheel air suspension system is comprised of the following components:
  • service switch
  • control module
  • two front height sensors
  • one rear height sensor
  • compressor and drier assembly (includes vent solenoid)
  • air lines
  • front and rear air spring and shock absorber assemblies
  • four air spring solenoids
s3j~us~en~file=ani_caut.gif~gen~ref.gif WARNING: The service switch for the air suspension system must be shut off prior to hoisting, jacking or towing an air suspension vehicle. This can be accomplished by turning off the air suspension switch located in the jack storage area in the rear of the passenger compartment. Failure to do so may result in unexpected inflation or deflation of the air springs which may result in shifting of the vehicle during these operations.
s3j~us~en~file=ani_caut.gif~gen~ref.gif WARNING: Do not remove an air spring under any circumstances when there is pressure in the air spring. Do not remove any components supporting an air spring without either exhausting the air or providing support for the air spring to prevent vehicle damage or personal injury.
Air Suspension Pneumatic Diagram 17d59a6.gif
Item Part Number Description 1 5319 Air compressor and drier 2 5B322 Air line T-fitting 3 5B321 Air line union 4 — Air line Y-fitting 5 18945/5311 Air spring and solenoid

Suspension Height Sensor Removal and Installation
NOTE: Front shown, rear similar
  1. s3j~us~en~file=ani_caut.gif~gen~ref.gif WARNING: The electrical power to the air suspension system must be shut off prior to hoisting, jacking or towing an air suspension vehicle. This can be accomplished by turning off the air suspension switch located in the LH quarter trim panel. Failure to do so may result in unexpected inflation or deflation of the air springs which may result in shifting of the vehicle during these operations.
    Raise and support the vehicle. For additional information, refer to Section 100-02 .
  1. Disconnect the sensor arm. 721ed10.gif
3. Remove the bolts and the sensor. b198e3c.gif
4.
  1. Disconnect the electrical connector.
---------------------------------------------------------------------------------------------

Ride Height Adjustments
Special Tool(s) s3j~us~en~file=st2332a.gif~gen~ref.gif Worldwide Diagnostic System (WDS)
418-F224

New Generation STAR (NGS) Tester
418-F052 or equivalent scan tool
Inflation and Deflation of the Air Suspension System
  1. NOTE: Make sure that the air suspension switch is in the ON position
    NOTE: Make sure that a battery voltage of at least 11 volts is maintained while carrying out this procedure.
    Turn the ignition switch to the ON position.
  1. Connect scan tool to the data link connector (DLC).
  1. Select Air Suspension Control Module under Active Command Mode:
    • VENT FRNT to deflate the front down.
    • LIFT FRNT to inflate the front up.
    • VENT REAR to deflate the rear down.
    • LIFT REAR to inflate the rear up.
Calibration
Ride Height Resetting
  1. NOTE: Make sure that the air suspension switch is in the ON position
    NOTE: Make sure that a battery voltage of at least 11 volts is maintained while carrying out this procedure.
    Turn the ignition to the ON position.
    • Exit the vehicle, close all doors and allow the system to vent the vehicle down to kneel height (approximately 45 seconds).
  1. With the ignition remaining in the ON position, shift the vehicle into DRIVE and then back to PARK.
    • Exit the vehicle, close all doors and allow the vehicle to pump to trim (approximately 45 seconds).
  1. Measure the ride height. For additional information, refer to Section 204-00 .
  1. Open the LF door.
  1. Connect scan tool to the data link connector (DLC).
  1. While outside of the vehicle, select the proper vehicle year, model and engine type.
  1. Select 4WAS module.
  1. Using the active command mode, vent or lift the vehicle to achieve the correct ride height.
  1. Select the "Save Calibration Values (Store Ride Height)" scan tool command to calibrate the 4WAS module.
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Jan 09, 2009 | 2003 Lincoln Navigator

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