OBD Code P0743

Torque Converter Clutch Circuit Electrical

What’s mean?

OBD2 Code P0743 Definition:
The Torque Converter Clutch (TCC) solenoid valve is activated, with the gear in D4, by the Transmission Control Module (TCM) in response to signals sent from the vehicle speed and the Engine Control Module (ECM). Lock-up piston operation will then be controlled. When the torque converter clutch solenoid valve is activated, the torque converter lockup clutch will engage creating a 1 to 1 RPM ratio between the transmission input shaft and the rotational speed of the torque converter. Lock-up operation, however, is prohibited when A/T fluid temperature is too low. When the accelerator pedal is depressed (less than 2/8) in lock-up condition, the engine speed should not change abruptly. If there is a big jump in engine speed, there is no lock-up.

Symptoms

Possible sumptoms of P0743
– Engine Light ON (or Service Engine Soon Warning Light)

Possible Causes

Possible causes of P0743
– Faulty torque converter clutch solenoid valve – Torque converter clutch solenoid valve harness or connectors – Torque converter clutch solenoid valve circuit is open or shorted – Low transmission fluid level – Dirty transmission fluid The Error code is generally activated on detection of the following conditions: By performing a voltage drop test, the ECM detects that the TCC solenoid circuit is open or shorted.

Possible Solutions