Rear air suspension doesn't inflate everytime vehicle is started

Air Suspension ??????

Air Suspension Description and Operation
Air Suspension
The primary mission of the Air Suspension System is the following for the rear suspension under loaded and unloaded conditions:
• Keep the vehicle visually level
• Provide optimal headlight aiming
• Maintain optimal ride height
The Air Suspension System consists of the following items:
• Air suspension compressor assembly
• Air suspension sensors
• Rear air springs
Important: The Air Suspension System must have a voltage supply of at least 12.6V to operate properly.
The Air Suspension System will maintain the rear D height within 4 mm (0.15 in) in all loading conditions and the leveling function will deactivate if the vehicle is overloaded. The side to side D height variation is maintained within 8 mm (0.31 in). After ignition is turned off, the air suspension control module (ASCM) will remain active for between 30 minutes and 2 1/2 hours. The system will exhaust pressure within 30 minutes after the ignition is turned off to lower the vehicle after unloading. In a temperature-controlled environment, the leakage of the complete load leveling system will not result in more than 1.4 mm (0.05 in) drop of rear suspension height at GVWR during a 24 hour period. If the outdoor temperature drops from +20°C (+68°F) to -5°C (+23°F), the rear D height may drop as much as 25 mm (1 in). However, the Air Suspension System should return to the specified D height when the ignition is again cycled to ON.

What is the problem ?

Diagnostic Trouble Code (DTC) Displaying
The Air Suspension system has an internal clock to prevent overheating if the compressor assembly is running for a prolonged period of time. If the system overheats, all leveling function stops until the system cools down. During this time, the indicator LED on the air inflator switch will be quickly flashing at a constant rate.
The other three diagnostic trouble codes are displayed with a blink code on the inflator switch LED. The Air Suspension Compressor Assembly shall begin to indicate the code when the condition to cause the code becomes current.
The number of the fault code shall be represented by the number of flashing pulses on the inflator switch LED. The flashing pulses shall have a repetition rate of 0.5 seconds and each code shall be separated by a 3.0 second delay. All codes shall be flashed in the order of occurrence of the fault. The blink code shall take priority over other processes that have access to the inflator switch LED. Refer to the following:
• DTC 001
• DTC 002
• DTC 003

Trim Height Uneven or Low ??????

The air bags are leaking, replace them as a pair.

Have the front airbags been replaced?? If the answer is no then you have found your problem. these bags last about 75,000-100,000.

the air ride suspension has level sensors under the vehicle, one of the sensors must be bad making the truck deflate the airbag or inflate it too much. you may need to have someone with a scan tool to access the air suspension module and check for fault codes. you can try turning the air suspension switch off for about an hour to see if the system will reset. the switch is located under the dash on the right side kick panel.

Okay the switch is in the back trunk area(I know it a SUV) in the back where you access the jacking tool youll see the switch make sure its on. Now some Navigator some have a shrader valve to pump up the suspension on the front area on driver side. As for the relay you might have to use a enhance scan tool to command it.By the way do you have a misfire?because if there is a misfire it will not inflate or a ABS light on? thse will also cause the suspension to not inflate

Replace the air suspension with conventional shock/strut
conversions. The Air Ride System is not worth investing
time and money ,after the vehicle is 5 years old.
Too expensive to maintain ,and too difficult to diagnose

Next time buy the Ford version of the vehicle

My suggestion to you and all the other folks leaving questions on this board about collapsed air suspension systems in luxury cars is to fix that one by replacing it with a real spring and shock system which you can buy at www.strutmasters.com if it is economically feasible, then sell it and avoid air suspensions systems like the plague. There are legions of old 70s Citroens still sitting idle 30 years later on collapsed air suspensions systems in garages and barns all over the country which cars the buyers can't let go because they cost so damn much. Get a coleman air mattress and use it every day, see how long it really lasts.

Hello! The rear suspension on this vehicle is air inflated. There are diaphrams that the level ride system uses to inflate rear shocks to aid in the comfort of the vehicles ride and handling. either an air line has rurtured,came off the connection at rear shock,or the diaphram itself has ruptured. Hope this information was helpful!

SECTION 204-05: Vehicle Dynamic Suspension 2000 Town Car Workshop Manual REMOVAL AND INSTALLATION Air Spring Removal
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.
WARNING: Disconnecting an air line that is connected to the air compressor can cause personal injury or damage to components as high pressure air is vented uncontrolled.

1. WARNING:
   • Do not attempt to install or inflate any rear air spring that has become unfolded to prevent vehicle damage or personal injury.
   • Failure to observe the following procedures may result in a sudden failure of the air spring or suspension system.
   • Any rear spring which is unfolded must be refolded prior to being installed in a vehicle.
   • The air spring refolding procedure should only be used for an air spring which has never supported the vehicle's weight while in the improperly folded position.
   • Improperly folded air springs found on vehicles during pre-delivery inspection or after use must be replaced.
   • Do not attempt to inflate any air spring which has been collapsed while uninflated from the rebound hanging position to the jounce stop.
   • When installing a new air spring, care must be taken not to apply a load to the suspension until springs have been inflated using the air spring fill procedure.
   • After inflating an air spring in the hanging position, it must be inspected for proper shape.
   
   NOTE: The vehicle must be positioned on a suitable lifting device prior to deflating the air suspension system.
   Vent the air suspension system. Refer to Ride Height Adjustments .

1. 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.
   Turn the air suspension switch off.

1. Raise and support the vehicle. For additional information, refer to Section 100-02 .

1. Remove the rear air spring retainer (5A966).

1. Lift the bottom of the air spring off the rear axle (4001).

1. Remove the air spring.
   1. Disconnect the electrical connector.
   1. Compress the quick connect locking ring and pull out the air line.
   1. Remove the air spring.

Installation

1. CAUTION: To avoid damage to the air spring, do not allow suspension to compress before the spring is inflated.
   NOTE: When installing the air lines, make sure the white air line is fully inserted into the fitting for correct installation.
   Install the air spring.
   1. Position the air spring assembly in the frame seat.
   1. Install the spring retainer clip.

1. Seat the bottom of the air spring on the rear axle (4001).

1. NOTE: When installing the air lines, make sure the white air line is fully inserted into the fitting for correct installation.
   Connect the air spring solenoid valve.
   1. Connect the electrical connector.
   1. Connect the air line.
   1. Make sure air spring is in the proper shape.

1. Refill the air springs; refer to Ride Height Adjustments .

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

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
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. 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.

3. Remove the bolts and the sensor.
4.

1. Disconnect the electrical connector.

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Ride Height Adjustments
Special Tool(s) 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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