DTC Advanced Diagnostics: P0602 (A/T System)
DTC P0602 : TCM Programming Error
General Description
The transmission control module (TCM) has a rewriting function that can be done in the field. The programs in the A/T CPU are the A/T control program (rewritable program) and the A/T update program (non-rewritable program). If the program rewriting process is not finished correctly, such as turning the vehicle to the OFF mode and turning it back ON during the rewriting process, the A/T CPU will store a DTC in the TCM.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | - |
| DTC Type | One drive cycle, MIL on, shift position indicator blinks |
Enable Conditions
| Condition | |
|---|---|
| Vehicle | ON mode |
Malfunction Threshold
The program rewriting process did not finish correctly due to an irregular process such as turning the vehicle to the OFF mode and turning it back ON during the rewriting process.
Possible Cause
- A/T CPU program unwritten
- TCM internal circuit failure
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on, the shift position indicator blinks, and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the TCM memory.
Conditions for clearing the DTC
The shift position indicator comes off by turning the vehicle to the OFF (LOCK) mode. The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool clear command.