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 the following condition twice per ignition cycle.

- 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.

TEST DESCRIPTION

Numbered steps below refer to numbered steps on chart.

1. This step verifies problem is still present.

2. If the actuator, 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 actuator or the actuator connector plate that is shorted. An actuator is shorted internally when its resistance is one or more ohms lower than the average resistance of the other actuators 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 actuators and no faults present for this actuator

DIAGNOSTIC AIDS

When attempting to diagnose an intermittent problem use the Scan tool* to review supplemental diagnostic information. The supplemental data can be used to duplicate a problem.

* Select MALF History and DTC status from DTC menu of Scan tool.

Check the tightness of the female terminal grip with a spare male terminal.

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.