P0742 CADILLAC Torque Converter Clutch Circuit Stuck On

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
Tech description
When the a transmission solenoid is stuck on, in most cases the problem is not the electrical part of the solenoid; the problem is foreign material obstructing the mechanical function of the solenoid or the flow of the fluid through the transmission valve body. If the transmission fluid is very dirty, it is recommend changing the transmission fluid and if possible removing the transmission pan for further diagnosis. Excessive debris or metal particles on the transmission pan could be an indication that there is a transmission mechanical failure and that the transmission will need to be rebuilt or replaced.
When is the obd code mean?
When the Powertrain Control Module (PCM) no longer provides a ground path, the Torque Converter Clutch (TCC) solenoid valve de-energizes and apply fluid exhausts, releasing the TCC.
When the PCM detects low torque converter slip when the PCM commands the TCC OFF, then is sets the P0742 code.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0742 CADILLAC OBD Code Description