This diagnostic procedure supports the following DTC:
DTC P0601 Transmission Control Module (TCM) Read Only Memory (ROM)
The transmission control module (TCM) detects a difference between the calculated checksum data and rear checksum data.
The TCM will request the illumination of the malfunction indicator lamp (MIL) and store the DTC when the TCM detects a failure on the first ignition cycle.
| • | The TCM turns off the MIL when no further failures are detected on the next ignition cycles. | 
| • | The scan tool can clear the DTC from the TCM history. | 
| • | The TCM clears the DTC from the TCM history memory after 40 consecutive ignition cycles without fault. | 
| • | Harness or connector between TCM and engine control module (ECM) | 
| • | ECM | 
| • | TCM | 
Step  | Action  | Yes  | No  | 
|---|---|---|---|
1  | 
 Is the malfunction indicator lamp (MIL) ON?  | Go to Step 2  | Go to Step 3  | 
2  | 
 Is DTC P0601 displayed?  | Go to Step 4  | Go to Step 3  | 
3  | Repair the temporary connection failure of the connector. Refer to Wiring Harness and Connector Inspection Diagnosis .  | System OK  | --  | 
4  | Replace the transmission control module (TCM). Refer to Transmission Control Module Replacement . Did you complete the replacement?  | System OK  | --  | 
This diagnostic procedure supports the following DTC:
DTC P0601 Transmission Control Module (TCM) Read Only Memory (ROM)
The transmission control module (TCM) detects a difference between the calculated checksum data and rear checksum data.
The TCM will request the illumination of the hold lamp and store the DTC when the TCM detects a failure on the first ignition cycle.
| • | The TCM turns off the hold lamp when no further failures are detected on the next ignition cycles. | 
| • | The scan tool can clear the DTC from the TCM history. | 
| • | The TCM clears the DTC from the TCM history memory after 40 consecutive ignition cycles without fault. | 
| • | Harness or connector between TCM and engine control module (ECM) | 
| • | ECM | 
| • | TCM | 
Step  | Action  | Yes  | No  | 
|---|---|---|---|
1  | 
 Is the hold lamp ON?  | Go to Step 2  | Go to Step 3  | 
2  | 
 Is DTC P0601 displayed?  | Go to Step 4  | Go to Step 3  | 
3  | Repair the temporary connection failure of the connector. Refer to Wiring Harness and Connector Inspection Diagnosis . Did you complete the repair?  | System OK  | --  | 
4  | Replace the transmission control module (TCM). Refer to Transmission Control Module Replacement . Did you complete the replacement?  | System OK  | --  |