Test Description
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. 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.
- 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. Any other body control module DTCs displayed by the scan tool do not apply to Remote Keyless Entry and should be diagnosed in the applicable section.
Diagnostic System Check - Remote Keyless Entry
| Step | Action | Yes | No |
|---|---|---|---|
| 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 |
IMPORTANT:
The engine may start during the following step. Turn OFF the engine as soon as you have observed the Crank power mode.
|
Go toStep 4 | Go toPower Mode Mismatch in Body Control System |
| 4 | Select the display DTCs function on the scan tool.
Does the scan tool display any DTCs? |
Go to Step 5 | Go to Symptoms - Keyless Entry |
| 5 | 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 Diagnostic Trouble Code (DTC) List in Body Control System |