Diagnostic Aids
WARNING: This page is about a different car, the 2005 Buick LaCrosse and 2005 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
- Do not replace the torque converter for this condition, refer to the Torque Converter Replacement Guide for other concerns.
- Ensure the wiring harness is not stretched too tightly or other components are pressing on the A/T inline 20-way connector body. Also inspect for proper clearance to any other components and wiring. Refer to Intermittent Conditions in Engine Controls - 3.6L.
DTC P0842 (3.6L)
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 2 |
IMPORTANT:
Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and Failure Records for reference. Using the Clear DTC Information function will erase the stored Freeze Frame and Failure Records from the TCM.
|
- | Go to Intermittent Conditions in Engine Controls - 3.6L | Go to Step 3 |
| 3 |
|
- | Go to Step 4 | Go to Step 5 |
| 4 | Test the TCC release switch signal circuit for a short to ground between the AT inline 20-way connector and the TFP manual valve position switch. Refer to Testing for Short to Ground in Wiring Systems. Did you find a condition? |
- | Go to Step 6 | Go to Step 7 |
| 5 | Test the TCC release switch signal for a short to ground between the TCM and the AT inline 20-way connector. Refer to Testing for Short to Ground andWiring Repairs in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 9 | Go to Step 8 |
| 6 | Replace the AT wiring harness assembly. Refer to Wiring Harness Replacement . Did you complete the replacement? |
- | Go to Step 9 | - |
| 7 | Replace the TFP manual valve position switch. Refer to Transmission Fluid Pressure (TFP) Manual Valve Position Switch Replacement . Did you complete the replacement? |
- | Go to Step 9 | - |
| 8 | Replace the TCM. Refer to Control Module References in Computer/Integrating Systems for replacement, set-up and programming. Did you complete the replacement? |
- | Go to Step 9 | - |
| 9 | Perform the following procedure in order to verify the repair:
Has the test run and passed? |
- | Go to Step 10 | Go to Step 2 |
| 10 | With a 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 in Vehicle DTC Information | System OK |