Troubleshooting

DTC P0863 TCM COMMUNICATION CIRCUIT

DTC Detection Condition:

CIRCUIT DESCRIPTION

MONITOR DESCRIPTION

Monitor Strategy:

Typical Malfunction Thresholds:

The transmission control ECU and the ECM communicate with each other using two-way communications via the Controller Area Network (CAN). The transmission control ECU sends signals concerning required engine rpm, required engine torques, warning indicators in the combination meter, DTCs, etc. The ECM sends signals concerning engine rpm, opening angles of the throttle valve, temperatures of intake air, temperatures of engine coolant, engine torques, etc. If the transmission control ECU cannot communicate with the ECM, the transmission control ECU will conclude that there is a malfunction of the CAN system, illuminate the MIL and set a DTC.

Wiring Diagram:

Step 1 - 3:

INSPECTION PROCEDURE

HINT:
- Read freeze frame data using hand-held tester or OBD II scan tool. Because freeze frame records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, etc. at the time of the malfunction.
- If the CAN communication malfunctions, there is no data output from the ECM. Some of the freeze frame data will not be correct and not identical with ECM data. In such a case, the ECM data are correct.