Test Description
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The number below refers to the step number on the diagnostic table.
- 3: This step tests for proper TCM battery direct voltage.
| Step | Action | Value | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Automatic Transmission Controls Schematics | ||||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 |
IMPORTANT:
Before clearing the DTC, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data.
|
B+ | Go to Diagnostic Aids | Go to Step 3 |
| 3 |
|
B+ | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 4 |
| 4 | Test the battery positive voltage circuit or the engine control module (ECM) B voltage circuit for loose or corroded connectors. Did you find and correct a condition? |
- | Go to Step 6 | Go to Step 5 |
| 5 |
IMPORTANT:
In most cases, the TCM is not at fault. Investigate thoroughly before replacing the TCM. Replace the TCM. Refer to Control Module References
for replacement, setup and programming.Did you complete the replacement? |
- | Go to Step 6 | - |
| 6 | Perform the following procedure in order to verify the repair:
Has the test run and passed? |
- | Go to Step 7 | Go to Step 2 |
| 7 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? |
- | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK |