How do I check for air suspension fault?

I have not looked at your part but there usually is a plastic panel cover on one of the rear quarter panels inside the rear cargo area. Sometimes it is paired with the inertia switch relay.

Wanted to inform you that some of the better scanners can diagnose Air suspension problems. Some of the big auto-parts stores offer free scans but few use the better scanner. Call ahead.

That could work , You mite be able to test the sensor in question with ohm meter . Test the front one an see what the resistance is ,then check the back one. I don't know what it should be with out looking it up in the service info . You could also check to see if the sensor is getting power from the control module , an see if there is a return input to the module .
There are a few DTC'S this able to set !
Air Suspension Control Module Diagnostic Trouble Code (DTC) Index
Air Suspension Control Module Diagnostic Trouble Code (DTC) Index DTCs Description Source Action B1318 Battery Voltage Low Air Suspension Control Module Go To Pinpoint Test C . B1342 Air Suspension Control Module Air Suspension Control Module INSTALL a new air suspension control module. REFER to Module-Air Suspension Control . SET the front ride height. REFER to Air Suspension Initialization (Clear DTC B2140). CLEAR the DTCs. REPEAT the self-test. B1485 Brake Pedal Input Circuit Battery Short Air Suspension Control Module RERUN On-Demand Self-Test. MAKE SURE that the brake pedal is not pressed. If DTC is returned again, REPAIR brake pedal position (BPP) circuitry. B1566 Door Ajar Circuit Short to Ground Air Suspension Control Module Go To Pinpoint Test D . B2140 Initialization Failure (Vehicle Ride Height Not Programmed) Air Suspension Control Module REFER to Air Suspension Initialization (Clear DTC B2140). C1439 Vehicle Acceleration EEC-V Circuit Failure Air Suspension Control Module Go To Pinpoint Test E . C1724 Air Suspension Height Sensor Power Circuit Failure Air Suspension Control Module Go To Pinpoint Test F . C1726 Air Suspension Pneumatic Failure Air Suspension Control Module Go To Pinpoint Test G . C1760 Air Suspension Height Sensor High Signal Circuit Failure Air Suspension Control Module Go To Pinpoint Test H . C1770 Air Suspension Vent Solenoid Output Circuit Failure Air Suspension Control Module Go To Pinpoint Test I . C1790 Air Suspension LR Air Spring Solenoid Output Circuit Failure Air Suspension Control Module Go To Pinpoint Test J . C1795 Air Suspension RR Air Spring Solenoid Output Circuit Failure Air Suspension Control Module Go To Pinpoint Test K . C1830 Air Suspension Compressor Relay Circuit Failure Air Suspension Control Module Go To Pinpoint Test L . C1917 Steering Electronic Variable Orifice (EEVO) Out-of-Range Fault Air Suspension Control Module Go To Pinpoint Test Q .

• Uneven vehicle height

• Circuitry.
• Rear pneumatic fault.
• Air compressor assembly.
• Air suspension control module.

• Go To Pinpoint Test I .

Best thing to do is have the OBD ( on-board diagnostics) system scanned for trouble codes. Places such as Auto Zone and Advance Auto may run a scan for free or for a low fee.

u can get code from most auto stores they offer free scanning but before bringing in check fuse -and power connection at compressor for power if compressor checks out fine look at the air lines to bags for breakage or disconnection -same goes for the bags

Have you considered look at the starter and making sure the wires, plugs, and it is grounded all okay. because that was what wrong with my cousins car.

SOUND LIKE FAULT IN THE IDLE AIR CONTROL VALVE.HAVE CAR CODE SCAN FOR FAULT CODE.

auto zone reader will sometimes not read codes. take it to your local garage and ask them to plug into it with an updated reader. i dont charge to read a code and i would hope they dont either. the o2 sensor could cause bad gas mileage. whens the last tune up done? check air filter. plugs? also check air in tires. low tires can cost fuel mileage as well. hope this helps

some code readers have problems reading the 94 -95 vehicles wasnt till 96 that it was required to have the 16 pin obdll system -but check the connection and try again if it still tells u cant communicate take truck to an auto store for a scan some such as auto zone/ advanced auto do it for free and also have ur scanner checked could have a bad wire connector

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

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Visual Inspection Chart Mechanical Electrical

• Restricted suspension movement
• Excessive vehicle load
• Cut, severed, or crimped air line(s)
• Damaged air spring(s)
• Height sensor damage
• Height sensor mounted incorrectly, disconnected, or damaged

• Central junction box (CJB):
  • Fuse 5 (15A)
• Battery junction box (BJB):
  • Fuse 8 (30A)
• Loose or corroded connectors
• Air suspension switch OFF

The air suspension control module is diagnosed using Super Star II Tester 418-F045 (007-0041B) or equivalent.
The test connector used to communicate with the air suspension control module is located on the RH side of the luggage compartment.
When the tester is connected, the engine is started and the HOLD/TEST button is latched down, the air suspension control module will respond sending a code 10 to the Super Star II Tester which represents "Diagnostics mode entered." If diagnostic trouble code (DTC) 10 is not displayed, go to Pinpoint Test A.
Air Suspension Control Module Diagnostic Trouble Code (DTC) Index
Condition Possible Sources Action

• No communication with the air suspension control module

• CJB Fuse 5 (15A).
• BJB Fuse 8 (30A).
• Circuitry.
• Air suspension control module.

• GO to Pinpoint Test A .

• Unable to enter auto test

• Air suspension control module.
• Circuitry.

• GO to Pinpoint Test B .

• Rear air suspension does not respond to load changes

• Circuitry.
• Air compressor.
• Air compressor inlet tube.
• Air compressor drier.
• Air suspension height sensor.
• Air suspension control module.

• GO to Pinpoint Test C .

• Rear rides low/high

• Circuitry.
• Air spring solenoid.
• Air suspension height sensor.
• Air suspension control module.

• GO to Pinpoint Test C .

• Poor ride quality

• Circuitry.
• Air springs.

• GO to Pinpoint Test C .

• Air suspension warning indicator ON

• Air suspension switch OFF.

• Place the air suspension switch in the ON position.

• Air suspension control module.
• Circuitry.

• GO to Auto Test.

• Instrument cluster (conventional cluster) or lamp warning module (electronic cluster).

• REFER to Section 413-01A (conventional cluster) or REFER to Section 413-01B (electronic cluster), or REFER to Section 413-01C (natural gas cluster).

Take the vehicle to an autoparts store and have them scan the computer for any fault codes that it has stored. Most parts stores will do the scan for free and getting the codes will end speculation as to the cause. The check engine light indicates that the computer has noted a fault in one of the vehicle's systems. What you describe could be caused by a faulty idle air control valve or it could even be more than one factor, but getting the codes should help narrow down the cause of the problem. Sure hope this helped and best wishes.