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P0743

Diagnostic Chart:




Schematic:




The Torque Converter Clutch (TCC) solenoid is used to apply and release TCC. The TCC can be applied in all forward gears. The PCM controls the TCC by pulse width modulating an internal driver that pulls the solenoid circuit to ground. When the TCC solenoid is commanded On (circuit grounded), the TCC is applied, which works opposite to all other four trans axle solenoids. The TCC solenoid circuit is monitored for low and high voltage faults. DTC P0743 sets when the TCC solenoid is commanded On (PWM On-time) and the feedback voltage at the PCM is high.

DTC PARAMETERS
DTC P0743 will set if TCC solenoid voltage is greater than 1.25 volts when TCC solenoid is being commanded On. Condition must exist twice in one ignition cycle.

DTC P0743 diagnostic runs continuously with engine running and TCC solenoid commanded On.

DTC P0743 is a type D DTC.

DIAGNOSTIC AIDS
To locate an intermittent problem, use Scan tool to command TCC SOLENOID On (PWM) by performing SOLENOID AUDIBLE CHECK. When a fault (short to voltage or shorted solenoid) exists, the solenoid will stop cycling.

If a short across the solenoid or a short to voltage on circuit 422 exists, the PCM will open the driver circuit for protection and the feedback voltage will be high.

TCC solenoid resistance: 3.8-7.2 ohms

Nominal value: 4.5 ohms at 68°F