What can occur when the torque converter clutch does not lock?
There are basically three ways a torque converter lockup clutch can fail: It can stay locked up, stalling the engine when the car is braked to a stop; it can never lock up, which shows up as an increase in fuel consumption and radiator temperature; or it can slip when engaged, allowing engine speed surges at a constant …
How do you unlock a torque converter clutch?
Unlocking the torque converter is achieved by disconnection of the +12 volts, or the transmission downshifts out of 4th gear. We also include a cruise control style brake switch that works perfectly to disconnect the +12 volt power to the lock up module when the brakes are applied.
What is the difference between a lock-up and non lockup torque converter?
Towing will add heat to the transmission. A non-lock-up torque converter will add more heat. With a lock-up when you get to speed, the torque converter will lock-up, which creates a direct drive from engine to transmission. No additional heat will be added into the tranny fluid due to slippage during operation.
What causes the torque convertor clutch to disengage?
There is a solenoid in your GM converter that causes the the torque convertor clutch (TCC) to engage and disengage. When the TCC solenoid receives a signal from the engine control module (ECM), it opens a passage in the valve body and hydraulic fluid applies the TCC.
What to do if your torque converter is stuck?
Mechanics would disconnect the four wire connector from the torque converter clutch solenoid. This was not a scientific test and if the solenoid was permanently stuck applied it would not tell you what was wrong with the car. But often simply disconnecting the clutch solenoid connector solved the shuddering or stalling condition.
Where is the torque converter clutch solenoid circuit located?
At certain speeds, the torque converter clutch (located inside the converter) creates a mechanical connection between the engine and transmission. The control module operates the TCC via one or more solenoid valves. Applying the TCC improves fuel economy, reduces engine speed, and lowers the temperature of the transmission fluid.
What causes a GM torque converter to lock up?
Most of the time it is a stuck Torque Converter Clutch (TCC) solenoid, but this is not the only cause of this problem. General Motors has issued a few Technical Service Bulletins (TSBs) relating to this problem. There is also a specific diagnostic procedure to determine the exact cause of the TCC problem.