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 numbers below refer to the step numbers on the diagnostic table.
- 3: This step tests the command signal from the TCM.
- 4: This step tests the resistance value of the external harness and solenoid.
- 5: This step tests the resistance value of the solenoid, and tests the internal wiring harness for opens.
- 6: This step tests the resistance value of the solenoid.
| 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.
|
Code Active | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections |
| 3 |
|
B+ | Go to Step 4 | Go to Step 5 |
| 4 | Using the scan tool, command the SS1 to ON. Did you get less than 0.5 volts with the solenoid commanded ON? |
< 0.5 volts | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 10 |
| 5 |
|
22.0 Ω at 20°C (68°F) | Go to Step 7 | Go to Step 6 |
| 6 |
|
22.0 Ω at 20°C (68°F) | Go to Step 8 | Go to Step 9 |
| 7 | Test the SS1 circuit between the TCM and the AT inline 20-way connector for an open condition. Refer to Testing for Continuity
. Did you find and correct the condition? |
- | Go to Step 11 | - |
| 8 | Replace the AT internal wiring harness. Refer to Wiring Harness Replacement
. Did you complete the replacement? |
- | Go to Step 11 | - |
| 9 | Replace the SS1. Refer to Control Valve Solenoid Replacement (SS1, SS2, SS3, TCC, and MAIN MOD)
or Control Valve Solenoid Replacement (PCS1 and PCS2)
. Did you complete the replacement? |
- | Go to Step 11 | - |
| 10 |
IMPORTANT:
In most cases, the TCM is not at fault. Investigate thoroughly before replacing the TCM. Swap the TCM with a known good TCM to confirm diagnosis. Replace the TCM. Refer to Control Module References
for replacement, setup and programming.Did you complete the replacement? |
- | Go to Step 11 | - |
| 11 | Perform the following procedure in order to verify the repair:
Has the test run and passed? |
- | Go to Step 12 | Go to Step 2 |
| 12 | 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 |