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 P1790 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 | -- |
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 P1790 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 | -- |