Initial Inspection and Diagnostic Overview

Inspection and Verification

CAUTION: Before diagnosing the rear air suspension system, carry out the RAS module self-test. If a DTC is present, follow the diagnosis and testing procedures. If no DTC is present, check the vehicle ride height by following the ride height adjustment procedure in this section.

If the system cannot reach the correct ride height, check all of the air supply lines and connections for leaks/blockage/or damage, height sensor integrity, and/or compressor relay operation before installing a new air compressor.
1. Verify the customer concern.

2. NOTE: If the door ajar indicator is illuminated, repair the door ajar indicator.

Visually inspect for obvious signs of mechanical and electrical damage.





Visual Inspection Chart

3. If the concern remains after the inspection, connect the scan tool to the data link connector (DLC) located beneath the instrument panel and select the vehicle to be tested from the scan tool menu. If the scan tool does not communicate with the vehicle:
^ check that the program card is correctly installed.
^ check the connections to the vehicle.
^ check the ignition switch position.
4. If the scan tool still does not communicate with the vehicle, refer to the scan tool manual.
5. Carry out the DATA LINK DIAGNOSTIC TEST. If the scan tool responds with:
^ CKT914, CKT915 or CKT70 = ALL ECUS NO RESP NOT EQUIP.
^ 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 (DTC'S), erase the continuous DTC'S and carry out self-test diagnostics for the rear air suspension control module and system pneumatic test.
6. If the DTC'S retrieved are related to the concern, go to Rear Air Suspension Control Module Diagnostic Trouble Code (DTC) Index to continue diagnostics.
7. If no DTC'S related to the concern are retrieved, GO to Symptom Chart to continue diagnostics. Symptom Related Diagnostic Procedures