Diagnostic Instructions
DTC Descriptors
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)
DTC P062F: Transmission Control Module (TCM) Long Term Memory Performance
Circuit/System Description
The internal fault detection is handled inside the TCM; no external circuits are involved.
Conditions for Running the DTC
This diagnostic applies to internal microprocessor integrity conditions within the TCM. This diagnostic also addresses if the TCM is not programmed.
Conditions for Setting the DTC
The TCM detects an internal condition.
Action Taken When the DTC Sets
P0601, P0603, P0604, and P062F
• | DTC P0601, P0602, P0603, P0604 and P062F are type A DTCs. |
• | The TCM commands maximum line pressure. |
• | The TCM forces the torque converter clutch (TCC) OFF. |
• | The TCM inhibits TCC engagement. |
• | The TCM freezes transmission adaptive functions. |
• | The TCM commands a soft landing to 2nd gear. |
P0602
• | DTC P0601, P0602, P0603, P0604 and P062F are type A DTCs. |
• | The TCM commands maximum line pressure. |
• | The TCM forces the torque converter clutch (TCC) OFF. |
• | The TCM inhibits TCC engagement. |
• | The TCM freezes transmission adaptive functions. |
• | The TCM commands an immediate landing to 2nd gear. |
Conditions for Clearing the DTC
DTCs P0601, P0602, P0603, P0604 and P062F are type A DTCs.
Diagnostic Aids
DTC P0602 indicates the TCM is not programmed.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Transmission General Description
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References
for scan tool information
Circuit/System Verification
- Ignition ON, clear the DTC information with a scan tool. Observe the scan tool DTC information. Verify that DTC P0602 does not fail this ignition.
⇒ | If DTC P0602 failed this ignition, reprogram the TCM. If DTC P0602 resets, replace the TCM. |
- Observe the DTC information with a scan tool. Verify that DTC P0601, P0603, P0604, or P062F do not set this ignition cycle.
⇒ | If DTC P0601, P0603, P0604, or P062F are set this ignition cycle, replace the TCM. |
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the repair.
Control Module References
for TCM replacement, setup, and programming.