P0864-TCM TORQUE REDUCTION SIGNAL ERROR
For a complete wiring diagram Refer to Section 8W
- When Monitored:
With the engine running.
- Set Condition:
The ECM detects a malfunction on the Torque Management Request Signal circuit.
| Possible Causes |
| ENGINE CONTROL MODULE |
| TORQUE MANAGEMENT REQUEST SIGNAL CIRCUIT OPEN |
| TORQUE MANAGEMENT REQUEST SIGNAL CIRCUIT SHORTED TO GROUND |
| TORQUE MANAGEMENT REQUEST SIGNAL CIRCUIT SHORTED TO VOLTAGE |
| TRANSMISSION CONTROL MODULE |
| INTERMITTENT CONDITION |
Diagnostic Test
1. CHECKING THE TORQUE MANAGEMENT REQUEST SIGNAL
Turn the ignition off.
Disconnect the TCM harness connectors.
Turn the ignition on.
Measure the voltage of the Torque Management Request Signal circuit at the TCM harness connector.
While monitoring the voltmeter wiggle the Torque Management Signal wiring and connectors between the ECM and TCM harness connectors.
Is the voltage steady between 4.5 and 5.5 volts while wiggling the wiring and connectors?
Yes
- Go To 2
No
- Go To3
2. TRANSMISSION CONTROL MODULE
Turn the ignition off.
Reconnect all connectors.
Turn the ignition on.
With the scan tool, erase ECM DTCs.
Test drive the vehicle.
With the scan tool, read the ECM DTCs.
Did this DTC set again?
Yes
- Replace and program the Transmission Control Module in accordance with the Service Information.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Test Complete.
3. TORQUE MANAGEMENT REQUEST SIGNAL CIRCUIT OPEN
Turn the ignition off.
Disconnect the ECM harness connectors.
Measure the resistance of the Torque Management Request Signal circuit.
Is the resistance below 10.0 ohms?
Yes
- Go To4
No
- Repair the Torque Management Request Signal circuit for an open.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
4. TORQUE MANAGEMENT REQUEST SIGNAL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the Torque Management Request Signal circuit.
Is the resistance above 1000 ohms?
Yes
- Go To5
No
- Repair the Torque Management Request Signal circuit for a short to ground.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
5. TORQUE MANAGEMENT REQUEST SIGNAL CIRCUIT SHORTED TO VOLTAGE
Remove the ASD Relay.
Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay connector.
Measure the voltage of the Torque Management Request Signal circuit.
Is the voltage below 1.0 volt?
Yes
- Replace and program the Engine Control Module in accordance with the Service Information.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Repair the Torque Management Request Signal circuit for a short to voltage.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).