Circuit Description
The internal fault detection is handled inside the transmission control module (TCM). No external circuits are involved.
DTC P0601 and P0604 are type A DTC's.
DTC P0602 and P0603 are type C DTC's.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC P0601 Transmission Control Module (TCM) Read Only Memory (ROM) |
| • | DTC P0602 Transmission Control Module (TCM) Not Programmed |
| • | DTC P0603 Transmission Control Module (TCM) Long Term Memory Reset |
| • | DTC P0604 Transmission Control Module (TCM) Random Access Memory (RAM) |
Conditions for Running the DTC
The TCM runs the program to detect an internal fault when the engine is running. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.
Conditions for Setting the DTC
The TCM has detected an internal malfunction.
Action Taken When the DTC Sets
| • | P0603, the TCM uses the initial EEPROM settings. |
| • | P0601 and P0604, the TCM requests the powertrain control module (PCM) to illuminate the malfunction indicator lamp (MIL). |
| • | P0601, the TCM allows the vehicle to operate in transmission protection mode. |
| • | The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record. |
| • | The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as a Freeze Frame. |
Conditions for Clearing the DTC
| • | The PCM turns off the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request. |
| • | A scan tool can clear the DTC. |
| • | The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring. |
| • | The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM. |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle in Vehicle DTC Information? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
Is DTC P0602 set? | Go to Step 3 | Go to Step 4 | |
3 | Program the TCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Does DTC P0602 reset? | Go to Step 4 | Go to Step 5 |
4 | Replace the TCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 5 | -- |
5 | Perform the following 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 DTC's that you have not diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |
