Possible causes

– Low transmission fluid level
– Dirty transmission fluid
– Faulty torque converter clutch solenoid valve
– Torque converter clutch solenoid valve harness or connectors
– Torque converter clutch solenoid valve circuit is open or shorted
– Transmission internal mechanical problem

When is the code detected?

Lock-up does not occur when driving in lock-up range or lockup remains ON in lock-up OFF range

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0741 CADILLAC Description

The torque converter clutch 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.

CADILLAC Technical Service Bulletins for P0741 code