Question about 2003 Lincoln Navigator

Open Question

What is the trim height spec for a 2003 navigator

Replaced air bags & seals on front. Replaced Comp. And relay. Would like to check trim & kneel height need specs and where di i measure from? Thank You

Posted by on

  • 1 more comment 
  • Richard Wallace Apr 18, 2014

    Add a CommentE

  • Richard Wallace Apr 18, 2014

    I need a measure from the ground to the frame(also where to measure at on the frame),

  • Richard Wallace Apr 18, 2014

    example: 12 inchs for kneel height to front jacking point under front door}

×

2 Suggested Answers

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

emissionwiz
  • 75822 Answers

SOURCE: Replaced ride height sensors and

I have repaired dozens of these air suspension problems and without a doubt the #1 cause is leaking air bags, which you make no mention of replacing, as far as the changes to the ride height programs go they are preset and not adjustable, nor do i recommend you try and alter the system by fooling around with the ride height sensors, any changes u may attempt to make can and will adversely affect handling. My experience? 35 years as a Ford dealer factory trained and certified master technician in all phases of this system.

Posted on Sep 30, 2010

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Air suspension 2003 e500 won air up after replaced air bags


Check the ride height sensor, check the pump motor relay, Use a scan tool to try turning the air suspension system on.

Feb 24, 2017 | Cars & Trucks

1 Answer

WHERE IS THE REAR HEIGHT SENSOR ON 2004 LINCOLN NAVIGATOR


Usually between the frame and the rear axles. A lever type device, should be fairly easy to locate. Check that the compressor is building air pressure and storage tank. Air bags not leaking and etc.

Feb 13, 2013 | 2004 Lincoln Navigator

2 Answers

My licoln navigator front suspension is not working..stays deflated


First, you should have a warning light telling you it is not working. There is a switch for the air suspension underneath the glovebox-right hand side or in the rear hatch area on the left panel..make sure it's on. If all 4 air bags are deflated it could mean the air pump or actuator is malfunctioning.

Dec 13, 2009 | 2004 Lincoln Navigator

1 Answer

Front end air suspension in cold weather acts up. I am in FL so I cannot imagine what it would do up north. It will correct itself after it has warmed up. The check air suspension message does NOT come on....


year?

SECTION 204-05: Vehicle Dynamic Suspension — 4-Wheel 2003 Expedition/Navigator Workshop Manual
DESCRIPTION AND OPERATION 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
-------------------------------------------------------------------------------
Principles of Operation
The 4-wheel air suspension (4WAS) module commands changes in vehicle height that are necessary for both the load leveling and the vertical height adjustment features.
The 4WAS load leveling feature automatically makes adjustments in vehicle height so that the vehicle is always at trim height, and that constant front-to-rear vehicle attitudes are maintained over the load range of the vehicle. Adjustments in height that are necessary to correct height differences between the vehicle left and right sides for the 4WAS system are restricted to what can be reliably achieved with three height sensors.
The height adjustment feature has three vehicle heights within a two-inch span:
Kneel height — improves the ease of entering and exiting by lowering the vehicle one inch below the trim height in the front and rear when the vehicle ignition is in the OFF or LOCK positions and the vehicle is stationary.
Trim height — normal vehicle ride position; vehicle moves to trim position when the ignition is ON, when the transmission is initially shifted to DRIVE or REVERSE mode, when all doors are closed or when speed of more than 24 km/h (15 mph) is detected.
Off-road height — improves ground clearance by raising the vehicle one inch above trim height in the front and rear when the vehicle is at 4x4 low modes and the vehicle speed is less than 40 km/h (25 mph).
The 4WAS module uses the universal bus protocol, (UBP), module communications network for sending and receiving various signals with the exception of speed, information from the three height sensors, and the air suspension service switch. For additional information about UBP, refer to Section 418-00 .
The 4WAS system holds vehicle height when any door or rear hatch is opened. The system stores front and rear vehicle height the moment any door is detected open. The system then maintains this height regardless of the addition or removal of a load. The system returns to its commanded height when all doors are closed or vehicle speed exceeds 24 km/h (15 mph).

---------------------------------------------------------------
Air Suspension Service Switch
The air suspension service switch signal is needed to wake up the 4WAS module. Without the module receiving this signal, the 4WAS system is inoperative at speeds below 24 km/h (15 mph) and will not react when the vehicle is raised or lowered. At speeds above 24 km/h (15 mph), the system will be active as if the air suspension service switch is in the ON position.
---------------------------------------------------------
Air Compressor
The 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 4WAS 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.
  • has a single port drier that can be replaced separately.
The vent solenoid:
  • allows air to escape from the system during venting actions.
  • is part of the air compressor cylinder head.
  • 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 4WAS module determines that lowering is required.
  • provides an escape route for pressurized air when system pressures exceed safe operating levels.
  • has a 1034 kPa (150 psi) internal relief valve.
  • is installed with the air compressor as a unit.
Air Spring
The 4WAS system has front and rear air springs. The air springs provide a varying spring rate proportional to the system's air pressure and volume. The air suspension system regulates the air pressure in each air spring by compressing and venting the system's air. Increasing air pressure (compressing) raises the vehicle; decreasing air pressure (venting) lowers 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 4WAS module command.
Air Lines and Fittings
NOTE: Apply a soapy water solution to the air lines to verify the location of air leaks. If the air lines are cut, ruptured or leaking, a service repair kit is available.
Nylon air lines with quick connect fittings connect to the air compressor and air spring solenoids. The compressor assembly output line is divided by the use of a fitting to supply the front and rear air springs. Fittings are also used to divide the air supply to the RH and LH air spring solenoids.
Air Suspension Height Sensors
There are two sensors used for the front suspension and one sensor used for the rear suspension. The sensors send a voltage signal to the 4WAS module. The output ranges from approximately 4.50 volts at minimum height (when the vehicle is low or in full jounce) to 0.50 volt at maximum height (when the vehicle is high or in full rebound). The sensors have a usable range of ± 45° compared to total suspension travel of 196 mm (7.84 in) at the front wheels and 240 mm (9.6 in) at the rear wheels. Therefore, the sensors are mounted to the suspension at a point where full suspension travel at the wheel is relative to the travel at the height sensor. The front height sensors are mounted to the frame and the links are attached to the upper arm ball studs. The rear height sensor is mounted to the frame and the link is attached to the rear lower arm ball stud.
When the height sensor indicates that the vehicle is lower than trim under normal driving conditions, the air compressor will turn on and pump compressed air to the system. When the sensor indicates that the vehicle is raised above trim under normal driving conditions, this will cause the air to be vented from the system to lower the vehicle to its trim height level.
Compressor Relay
A solid state relay is used in the air suspension system for 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 4WAS module.
The compressor solid state relay is energized by the 4WAS module to have high current flow from the battery to the compressor motor.
4-Wheel Air Suspension (4WAS) Module
NOTE: The 4WAS module must receive a ride height adjustment calibration and must pass a pneumatic test when it is installed new or swapped.
The 4-wheel air suspension (4WAS) module controls the air compressor motor (through a solid state relay), all air spring solenoids, and provides power to front and rear height sensors. The 4WAS module also controls vehicle height adjustments by monitoring the three height sensors and other universal bus protocol (UBP) signals. The 4WAS module conducts all fail-safe and diagnostic strategies, and contains self-test and communication software for testing the vehicle and related components.
The 4WAS module monitors and controls the air suspension system through a 26-pin, two-way connector. The 4WAS module is keyed so that it cannot be plugged into an incorrect harness. There are two harness hardshell connectors and each is uniquely colored and keyed to prevent reversed connections.
-----------------------
  • The air compressor continuously cycles with the ignition switch in the OFF position and no DTC is set
  • Circuitry.
  • Air suspension relay.
  • 4WAS module.

Oct 21, 2009 | Lincoln Navigator Cars & Trucks

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

2 Answers

2003 ford navigator rear air susp. will not lower - at max ht.


sensor could be bad, telling the unit that it was too low so the comp just kept pumping it up??I think there are solenoids at each bag? really cant remember. isnt there a switch in the rear compartment to turn the susp off.

Sep 23, 2009 | 2003 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

5 Answers

Lincoln navigator air suspension is all the way down


that should not happen. Did you turn the switch off in the back for the suspension? Did you do something else at the same time, like check the spare tire for air pressure?

I have info on 2003 navigator 4 wheel air suspension. Maybe similar

SECTION 204-05: Vehicle Dynamic Suspension — 4-Wheel 2003 Expedition/Navigator Workshop Manual
DESCRIPTION AND OPERATION 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
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.

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 801e0c4.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
------------------------------
Principles of Operation
The 4-wheel air suspension (4WAS) module commands changes in vehicle height that are necessary for both the load leveling and the vertical height adjustment features.
The 4WAS load leveling feature automatically makes adjustments in vehicle height so that the vehicle is always at trim height, and that constant front-to-rear vehicle attitudes are maintained over the load range of the vehicle. Adjustments in height that are necessary to correct height differences between the vehicle left and right sides for the 4WAS system are restricted to what can be reliably achieved with three height sensors.
The height adjustment feature has three vehicle heights within a two-inch span:
Kneel height — improves the ease of entering and exiting by lowering the vehicle one inch below the trim height in the front and rear when the vehicle ignition is in the OFF or LOCK positions and the vehicle is stationary.
Trim height — normal vehicle ride position; vehicle moves to trim position when the ignition is ON, when the transmission is initially shifted to DRIVE or REVERSE mode, when all doors are closed or when speed of more than 24 km/h (15 mph) is detected.
Off-road height — improves ground clearance by raising the vehicle one inch above trim height in the front and rear when the vehicle is at 4x4 low modes and the vehicle speed is less than 40 km/h (25 mph).
The 4WAS module uses the universal bus protocol, (UBP), module communications network for sending and receiving various signals with the exception of speed, information from the three height sensors, and the air suspension service switch. For additional information about UBP, refer to Section 418-00 .
The 4WAS system holds vehicle height when any door or rear hatch is opened. The system stores front and rear vehicle height the moment any door is detected open. The system then maintains this height regardless of the addition or removal of a load. The system returns to its commanded height when all doors are closed or vehicle speed exceeds 24 km/h (15 mph).

-------------------------------
Air Suspension Service Switch
The air suspension service switch signal is needed to wake up the 4WAS module. Without the module receiving this signal, the 4WAS system is inoperative at speeds below 24 km/h (15 mph) and will not react when the vehicle is raised or lowered. At speeds above 24 km/h (15 mph), the system will be active as if the air suspension service switch is in the ON position.
Vehicles without message center When the air suspension service switch is in the OFF position and the ignition switch is in the RUN position, a "CHECK SUSP" will appear in the RH corner of the instrument cluster.
Vehicles with message center When the air suspension service switch is in the OFF position and the ignition switch is in the RUN position, the message center will display "SUSPENSION SWITCHED OFF"
-------------------------------------------
Inspection and Verification
  1. Verify the customer concern.
  1. NOTE: If the door ajar indicator is illuminated when all doors, liftgate, and liftgate glass are closed, the air suspension will not work correctly. Repair door ajar indicator; refer to Section 413-01 .
    Visually inspect for obvious signs of mechanical and electrical damage.


Visual Inspection Chart Mechanical Electrical
  • Restricted suspension movement
  • Excessive vehicle load
  • Cut, severed, crimped air line(s)
  • Unmounted height sensor(s)
  • Damaged front air spring(s)
  • Damaged rear air spring(s)
  • Battery junction box (BJB) fuses 20 (30A), fuse 27 (5A), and fuse 111 (50A)
  • Loose, corroded, or disconnected connectors
  • Air suspension service switch is in the OFF position
  • Damaged solenoid valve(s)

-------------------------
I fthis does not help, the dealer can hook up his diagnostic equipment and download fault codes. Good luck. Please give best rating if this helps.

Apr 20, 2009 | 2004 Lincoln Navigator

2 Answers

AIR SUSPENTION WORKS ABNORMALY


a lot of info here:
Principles of Operation
The 4-wheel air suspension (4WAS) module commands changes in vehicle height that are necessary for both the load leveling and the vertical height adjustment features.
The 4WAS load leveling feature automatically makes adjustments in vehicle height so that the vehicle is always at trim height, and that constant front-to-rear vehicle attitudes are maintained over the load range of the vehicle. Adjustments in height that are necessary to correct height differences between the vehicle left and right sides for the 4WAS system are restricted to what can be reliably achieved with three height sensors.
The height adjustment feature has three vehicle heights within a two-inch span:
Kneel height — improves the ease of entering and exiting by lowering the vehicle one inch below the trim height in the front and rear when the vehicle ignition is in the OFF or LOCK positions and the vehicle is stationary.
Trim height — normal vehicle ride position; vehicle moves to trim position when the ignition is ON, when the transmission is initially shifted to DRIVE or REVERSE mode, when all doors are closed or when speed of more than 24 km/h (15 mph) is detected.
Off-road height — improves ground clearance by raising the vehicle one inch above trim height in the front and rear when the vehicle is at 4x4 low modes and the vehicle speed is less than 40 km/h (25 mph).
The 4WAS module uses the universal bus protocol, (UBP), module communications network for sending and receiving various signals with the exception of speed, information from the three height sensors, and the air suspension service switch. For additional information about UBP, refer to Section 418-00 .
The 4WAS system holds vehicle height when any door or rear hatch is opened. The system stores front and rear vehicle height the moment any door is detected open. The system then maintains this height regardless of the addition or removal of a load. The system returns to its commanded height when all doors are closed or vehicle speed exceeds 24 km/h (15 mph).


Vehicle Height Modes Ignition State Transfer Case Mode Speed or Speed Range Resulting Vehicle Height OFF 4x2, A4WD, 4x4 HI N/A Kneel (TRIM - 25 mm) ON and RUN 4x2, A4WD, 4x4 HI All speeds TRIM ON and RUN 4x4 Low Below 40 km/h (25 mph) Off-Road (TRIM + 25 mm) ON and RUN 4x4 Low Above 40 km/h (25 mph) TRIM OFF 4x4 Low N/A Stays at current position (prior to ignition transition)
Air Suspension Service Switch
The air suspension service switch signal is needed to wake up the 4WAS module. Without the module receiving this signal, the 4WAS system is inoperative at speeds below 24 km/h (15 mph) and will not react when the vehicle is raised or lowered. At speeds above 24 km/h (15 mph), the system will be active as if the air suspension service switch is in the ON position.
Vehicles without message center When the air suspension service switch is in the OFF position and the ignition switch is in the RUN position, a "CHECK SUSP" will appear in the RH corner of the instrument cluster.
Vehicles with message center When the air suspension service switch is in the OFF position and the ignition switch is in the RUN position, the message center will display "SUSPENSION SWITCHED OFF"
Air Compressor
The 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 4WAS 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.
  • has a single port drier that can be replaced separately.
The vent solenoid:
  • allows air to escape from the system during venting actions.
  • is part of the air compressor cylinder head.
  • 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 4WAS module determines that lowering is required.
  • provides an escape route for pressurized air when system pressures exceed safe operating levels.
  • has a 1034 kPa (150 psi) internal relief valve.
  • is installed with the air compressor as a unit.
Air Spring
The 4WAS system has front and rear air springs. The air springs provide a varying spring rate proportional to the system's air pressure and volume. The air suspension system regulates the air pressure in each air spring by compressing and venting the system's air. Increasing air pressure (compressing) raises the vehicle; decreasing air pressure (venting) lowers 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 4WAS module command.
Air Lines and Fittings
NOTE: Apply a soapy water solution to the air lines to verify the location of air leaks. If the air lines are cut, ruptured or leaking, a service repair kit is available.
Nylon air lines with quick connect fittings connect to the air compressor and air spring solenoids. The compressor assembly output line is divided by the use of a fitting to supply the front and rear air springs. Fittings are also used to divide the air supply to the RH and LH air spring solenoids.
Air Suspension Height Sensors
There are two sensors used for the front suspension and one sensor used for the rear suspension. The sensors send a voltage signal to the 4WAS module. The output ranges from approximately 4.50 volts at minimum height (when the vehicle is low or in full jounce) to 0.50 volt at maximum height (when the vehicle is high or in full rebound). The sensors have a usable range of ± 45° compared to total suspension travel of 196 mm (7.84 in) at the front wheels and 240 mm (9.6 in) at the rear wheels. Therefore, the sensors are mounted to the suspension at a point where full suspension travel at the wheel is relative to the travel at the height sensor. The front height sensors are mounted to the frame and the links are attached to the upper arm ball studs. The rear height sensor is mounted to the frame and the link is attached to the rear lower arm ball stud.
When the height sensor indicates that the vehicle is lower than trim under normal driving conditions, the air compressor will turn on and pump compressed air to the system. When the sensor indicates that the vehicle is raised above trim under normal driving conditions, this will cause the air to be vented from the system to lower the vehicle to its trim height level.
Compressor Relay
A solid state relay is used in the air suspension system for 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 4WAS module.
The compressor solid state relay is energized by the 4WAS module to have high current flow from the battery to the compressor motor.
4-Wheel Air Suspension (4WAS) Module
NOTE: The 4WAS module must receive a ride height adjustment calibration and must pass a pneumatic test when it is installed new or swapped.
The 4-wheel air suspension (4WAS) module controls the air compressor motor (through a solid state relay), all air spring solenoids, and provides power to front and rear height sensors. The 4WAS module also controls vehicle height adjustments by monitoring the three height sensors and other universal bus protocol (UBP) signals. The 4WAS module conducts all fail-safe and diagnostic strategies, and contains self-test and communication software for testing the vehicle and related components.

Jan 06, 2009 | 2003 Lincoln Navigator

Not finding what you are looking for?
2003 Lincoln Navigator Logo

Related Topics:

34 people viewed this question

Ask a Question

Usually answered in minutes!

Top Lincoln Experts

yadayada
yadayada

Level 3 Expert

75822 Answers

fordexpert

Level 3 Expert

5501 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers

Are you a Lincoln Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...