P0743

Diagnostic Chart:

Wiring Diagram:

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.

DTC PARAMETERS
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 chart.
1. This step verifies 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 one or more ohms lower than the average resistance of the other solenoids at the same temperature.

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

Criteria for pass:
^ Engine running
^ Power at solenoids and no faults present for this actuator

DIAGNOSTIC AIDS
When the PCM detects a fault in the circuit (open, ground, 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 - No TCC.