For 1990-2009 cars

### Circuit Description

The torque converter clutch (TCC) actuator is applied when circuit 422 is grounded at the PCM. When the PCM grounds the circuit, the voltage is monitored at terminal J4A02 to check for proper circuit conditions.

### Conditions for Setting the DTC

DTC P0743 is set when the PCM has detected voltage monitored at terminal J4A02, circuit 422, is greater than 2-2.5 volts when the TCC solenoid valve is switched ON electrically by the PCM, twice per ignition cycle.

### Test Description

Numbered steps below refer to numbered steps on the chart.

1. This step verifies the problem is still present.
2. If the solenoid, connector plate, or circuit 422 is shorted, DTC P0743 will set. This step will break down the circuit to find the source of the short.
3. If circuit 422 is shorted to voltage, DTC P0743 will set. This step checks circuit 422 for a short to voltage.
4. This step will determine if it is the solenoid or the solenoid connector plate that is shorted. A solenoid is shorted internally when its resistance is 1 or more ohms lower than the average resistance of the other solenoids at the same temperature.

### Repair Verification

Monitor the DTC menu Code Status for Pass Since Code Clear and Pass This Ignition Cycle. When both have passed, the repair is verified.

Criteria for pass:

• | The engine is running.

• | Power at the solenoids and no faults are present for this actuator.

### Diagnostic Aids

When the PCM detects a fault in the circuit, an open, ground, or short, the PCM will open the circuit internally to protect the circuit.

A short to voltage on circuit 422 will probably set a DTC P0741.