Initial Inspection and Diagnostic Overview

1. Verify the customer concern.
2. Visually inspect for obvious signs of mechanical and electrical damage. If the inspection reveals an obvious concern that is readily repaired, correct the concern before continuing with Inspection and Verification.

Mechanical
- Restricted suspension movement
- Excessive vehicle load
- Detached height sensor
- Crimped, kinked, or leaking air line

Electrical
- Air suspension switch is OFF
- Blown fuse:
- Power distribution box-maxi fuse 11 (60A), mini fuse 4 (30A)
- I/P fuse panel- fuse 28 (10A)
- Loose connectors
- Corroded connectors

3. If the concern remains after the inspection, connect the 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 menu. If the NGS 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.
4. If the NGS Tester still does not communicate with the vehicle, refer to the scan tool manual.
5. Perform the DATA LINK DIAGNOSTIC TEST
If the NGS Tester responds with:
- CKT914, CKT915 or CKT70 = ALL ECUS NO RESP/NOT EQUIP.
- NO RESP/NOT EQUIP for Vehicle Dynamic Module (VDM), go to Pinpoint Test W.
- SYSTEM PASSED, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and perform self test diagnostics for the Vehicle Dynamic Module.
6. If the DTCs retrieved are related to the concern, go to Vehicle Dynamic Module Diagnostic Trouble Code (DTC) Index.
7. If no DTCs related to the concern are retrieved, proceed to Symptom Chart to continue diagnostics. Symptom Related Diagnostic Procedures