Diagnostic Aids
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.
DTC P0602 may set because of improper TCM reprogramming.
| Step | Action | 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.
|
Go to Step 3 | Go to Diagnostic Aids |
| 3 | Perform the transmission control module programming procedure. Refer to Control Module References
for replacement, setup, and programming. Did DTC P0602 set again? |
Go to Step 4 | Go to Step 5 |
| 4 |
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 5 | - |
| 5 | Perform the following procedure in order to verify the repair:
Has the test run and passed? |
Go to Step 6 | Go to Step 2 |
| 6 | 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 |