Troubleshooting

DTC P0860 GEAR SHIFT MODULE COMMUNICATION CIRCUIT*

*: Only for sequential manual transmission vehicle.

CIRCUIT DESCRIPTION

DTC Detection Condition:

The transmission control ECU and ECM communicate with each other though the CAN communication line.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Condition:

Typical Malfunction Thresholds:

The transmission ECU and the ECM perform two-way communications with each other via the Controller Area Network (CAN). The transmission ECU sends signals to the ECM concerning required engine rpm, required engine torques, warning indicators in the combination meter, DTCs, and other data. The ECM sends signals to the transmission ECU concerning engine rpm, opening angles of the throttle valve, temperature of intake air, temperature of engine coolant, engine torques, and other data.

If the transmission ECU cannot communicate with the ECM, the transmission ECU will conclude that there is a malfunction in the CAN system, illuminate the MIL and set a DTC.

Wiring Diagram:

Step 1 - 2:

Step 3:

INSPECTION PROCEDURE

HINT:
- If DTCs P0860 and P1646 are output simultaneously, the fail-safe function stops the engine. It the engine is stopped, the transmission control system may be abnormal.
- Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, this is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.