Test Description
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers on the diagnostic table.
- 2: Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
- 3: Check for the presence of DTCs.
- 4: The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.
- 5: Check for the presence of DTCs in Body Control system.
- 6: Check for the presence of DTCs in Automatic Level Control system.
Diagnostic System Check - Automatic Level Control
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Automatic Level Control Suspension Schematics | |||
| 1 | Install a scan tool. Does the scan tool power up? |
Go to Step 2 | Go to SCAN TOOL DOES NOT POWER UP in Data Link Communications |
| 2 |
|
Go to Step 3 | Go to SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE in Data Link Communications |
| 3 | Select the suspension control module display DTCs function on the scan tool. Does the scan tool display any DTCs? |
Go to Step 4 | Go to Symptoms - Automatic Level Control |
| 4 | Does the scan tool display any DTCs which begin with a "U"? | Go to SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE in Data Link Communications | Go to Step 5 |
| 5 | Does the scan tool display DTC B1000? | Go to DIAGNOSTIC TROUBLE CODE (DTC) LIST in Body Control System | Go to Step 6 |
| 6 | Does the scan tool display DTC C0655, C0660, or C0711? | Go to Diagnostic Trouble Code (DTC) List | Go to DIAGNOSTIC TROUBLE CODE (DTC) LIST in Real Time Damping |