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DTC - Diagnostic Trouble Codes information

P0742

Powertrain Codes

P0742 - SUZUKI - Torque Converter Clutch Solenoid Performance Or Stuck On

Symptoms

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

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 Detected

The TCM has detected slippage on the TCC during a period when the converter is commanded off

Tech Notes

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.

Description

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.