Diagnostic Test
- CHECK FOR ENGINE DTC PRESENT
- With the scan tool, check engine DTCs.
Are there any engine DTCs present?
Yes
- Refer to DIAGNOSTIC CODE INDEX and perform the appropriate diagnostic procedure.
No
- Go To 2
- With the scan tool, check engine DTCs.
- CHECK FOR ANY DRIVEABILITY CONCERNS
- Check that the engine performs properly.
Does the engine perform correctly, with no complaints of roughness or stall out?
Yes
- Go To 3.
No
- Repair the cause of incorrect engine performance.
Refer to DIAGNOSIS AND TESTING .
- Check that the engine performs properly.
- CHECK FOR CAN BUS DTCS
- With the scan tool, check for any CAN bus DTCs or a sign of a CAN bus failure.
Are there any CAN bus DTCs present in any module other than the TCM or an overall indication of a CAN bus communication problem?
Yes
- This is an indication of a CAN bus communication problem. Depending on the DTC, refer to DTC Based Diagnostics and Non DTC Based Diagnostics for diagnostic procedures and other possible causes.
- Perform the NAG1 TRANSMISSION VERIFICATION TEST. Refer to NAG1 TRANSMISSION VERIFICATION TEST .
No
- Go To 4
- With the scan tool, check for any CAN bus DTCs or a sign of a CAN bus failure.
- CHECK IF DTC RESETS
- Turn the ignition off to the lock position.
- Replace and program the Powertrain Control Module in accordance with the Service Information.
- With the scan tool, record the Environmental Data and erase Transmission DTCs.NOTE:
If the TCM detects and stores a DTC, the TCM also stores the vehicles operating conditions under which the DTC originally set and is located in scan tool under Environmental Data. Before erasing any stored DTCs, record any available data to assist in duplicating the conditions in which the DTC originally set.
- Using the Environmental Data recorded earlier, test drive the vehicle while trying to duplicate the conditions in which the DTC originally set.
- With the scan tool, read Transmission DTCs.
Did the DTC P2638-TORQUE MANAGEMENT FEEDBACK SIGNAL PERFORMANCE reset?
Yes
- Using the schematics as a guide, check the Transmission Control Module (TCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the TCM in accordance with the Service Information.
- Perform the NAG1 TRANSMISSION VERIFICATION TEST. Refer to NAG1 TRANSMISSION VERIFICATION TEST .
No
- Test Complete.
- Perform the NAG1 TRANSMISSION VERIFICATION TEST. Refer to NAG1 TRANSMISSION VERIFICATION TEST .