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.
- 3: 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.
- 4: Determine if the Instrument Cluster or Powertrain Control Modules have set DTCs which may affect Engine Cooling operation are present.
- 5: 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.
Diagnostic System Check - Engine Cooling
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | Did you review a Diagnostic Starting Point-Engine Cooling? | Go to Step 2 | Go to DIAGNOSTIC STARTING POINT - Engine Cooling |
| 2 | Install a scan tool. Does the scan tool power up? |
Go to Step 3 | Go to SCAN TOOL DOES NOT POWER UP |
| 3 |
|
Go to Step 4 | Go to SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE |
| 4 | Select the powertrain control module display DTCs function on the scan tool. Does the scan tool display any DTCs? |
Go to Step 5 | Go to SYMPTOMS - Engine Cooling |
| 5 | Does the scan tool display any DTCs which begin with a "U"? | Go to SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE | Go to Step 6 |
| 6 | Does the scan tool display any DTCs that are associated with the Engine Cooling System? | Go to Diagnostic Trouble Code (DTC) List | Go to SELF-DIAGNOSTICS - 4.8L, 5.3L & 6.0L or SELF-DIAGNOSTICS - 8.1L "C", "G" & "K" SERIES TRUCKS |