For 1990-2009 cars

## DTC P0601 European Emissions

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0601 Transmission Control Module (TCM) Read Only Memory (ROM)

### Conditions for Setting the DTC

The transmission control module (TCM) detects a difference between the calculated checksum data and rear checksum data.

### Action Taken When the DTC Sets

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.

### Conditions for Clearing the DTC

• | 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.

### Cause of Failure

• | Harness or connector between TCM and engine control module (ECM)

• | ECM

• | TCM

Step | Action | Yes | No
--- | --- | --- | ---
1 |

1. Turn OFF the ignition.
2. Install the scan tool.
3. Turn ON the ignition, with the engine OFF.
4. Select Store Freeze Frame/Failure Records from the Diagnostic Trouble Codes Information menu.
5. Store Freeze Frame/Failure Records.
6. Select Clear DTC Information from the Diagnostic Trouble Codes Information menu.
7. Clear DTC Information.
8. Perform 2 vehicle drive cycles.

Is the malfunction indicator lamp (MIL) ON?

Go to Step 2

Go to Step 3

2 |

1. Select Request DTC by Status from the Diagnostic Trouble Codes Information menu.
2. Request DTC by Status.

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 | --

## DTC P0601 Non European Emissions

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0601 Transmission Control Module (TCM) Read Only Memory (ROM)

### Conditions for Setting the DTC

The transmission control module (TCM) detects a difference between the calculated checksum data and rear checksum data.

### Action Taken When the DTC Sets

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.

### Conditions for Clearing the DTC

• | 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.

### Cause of Failure

• | Harness or connector between TCM and engine control module (ECM)

• | ECM

• | TCM

Step | Action | Yes | No
--- | --- | --- | ---
1 |

1. Turn OFF the ignition.
2. Install the scan tool.
3. Turn ON the ignition, with the engine OFF.
4. Select Store Freeze Frame/Failure Records from the Diagnostic Trouble Codes Information menu.
5. Store Freeze Frame/Failure Records.
6. Select Clear DTC Information from the Diagnostic Trouble Codes Information menu.
7. Clear DTC Information.
8. Perform 2 vehicle drive cycles.

Is the hold lamp ON?

Go to Step 2

Go to Step 3

2 |

1. Select Request DTC by Status from the Diagnostic Trouble Codes Information menu.
2. Request DTC by Status.

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 | --