What would cause a torque converter to lock-up?

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.

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.

Where is the lockup clutch in a transmission converter?

To prevent slipping at certain speeds (normally speeds exceeding 37 mph) a lockup clutch located inside the converter locks the engine’s output drive to the transmission’s input shaft to achieve a 1:1 ratio – meaning 100% of the engine’s power is now reaching the transmission.

What happens when a torque converter goes bad?

A transmission that slips while in lockup because the system is overloaded will generate tremendous heat. These situations normally end with complete transmission failure. A faulty torque converter clutch solenoid normally sets a Diagnostic Trouble Code (DTC), which causes the Check Engine Light to come on.

What would cause a torque converter to lock up?

1. Engine temperature too cold – most converters will not lockup until the coolant reaches about 120°F. 2. Overdrive unit locked out – when an automatic overdrive is “locked-out” the torque converter lockup feature will also be locked out.

How do I know if my TCC solenoid is bad?

Symptoms Of Failing TCC Solenoid The main symptom of a TCC solenoid failure is the converter is not locking up. When the converter is not locking up you will notice the engine’s RPMs staying higher under load at highway speeds. Another symptom of a failed TCC solenoid is a fault code.

What happens to the solenoid on a torque converter?

When the ECM signal stops, the solenoid closes the valve and pressure is vented, causing the TCC to disengage. This lets the torque converter lock in “gear” or unlock out of “gear.”

Can You unplug the solenoid on a GM converter?

Generally, if you unplug the TCC solenoid at the transmission and the symptoms go away, you have found the problem. But sometimes this can be misleading because you don’t know for sure if it’s a bad solenoid, dirt in the valve body or a bad signal from the ECM.

What causes the torque convertor clutch to disengage?

What causes the torque converter to lock in gear?

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. When the ECM signal stops, the solenoid closes the valve and pressure is vented, causing the TCC to disengage. This lets the torque converter lock in “gear” or unlock out of “gear.”

Where is the solenoid valve on a torque converter?

Today we’ll be dealing with a Torque Converter Clutch Solenoid Valve. You will see how to locate, remove and test this solenoid valve. The torque converter on an automatic transmission transmits engine torque and power to the transmission. To prevent slippage a lockup clutch is located inside the converter.

What does the TCC solenoid do on a toque converter?

What Does The TCC Solenoid Do? The main function of the toque converter clutch or TCC solenoid is to send pressurized fluid to the torque converter’s clutch allowing it to achieve lock up in 4th gear based on a signal from the engine control module (ECM).

Where is the solenoid valve on an automatic transmission?

You will see how to locate, remove and test this solenoid valve. The torque converter on an automatic transmission transmits engine torque and power to the transmission. To prevent slippage a lockup clutch is located inside the converter.

Where is the TCC solenoid located on a 4L60E?

In essence, the TCC solenoid is like a computer controlled on and off switch for your 4l60e’s torque converter lock up. Where Is The TCC Solenoid Located The 4l60e TCC Solenoid is located on the front passenger side of the transmission near the valve body. The image below shows the locations of various solenoids.