torque converter solenoid plug

[samuraitekno]

I am having a trans problem and i asked the trans guy at my work about it and he said that it sounds like my torque converter is locking and unlocking back and forth. What it does is when i am cruising after about 10 minutes my car will fluctuate rpms about 300 up and down. that is only if i have my foot on the gas. if i dont the problem goes away. If i have the overdrive off and it is in a different rpm range i dont have the problem either. so he suggested that i can test this by unpluging the connector for the torque converter lockup solenoid. Now i have looked on alldata and on this website but i can not figure out what plug i need to unplug to test this. So any help would be appreciated. This is on a 1990 talon non turbo automatic.

 

[samuraitekno]

so if anyone is having the same problem as me i found out it was my torque converter lockup solenoid. There is a plug at your transmission that has 4 wires going to it in a square plug. The red wire controls the solenoid that tries to lock the torque converter. well mine was locking and unlocking..over and over. so i removed the wire from the harness and test drove the car and now no problem. so deeper investigation is going to have to happen but i know its the solenoid . so now i need to figure out if it is bad or the trans computer is telling it to open and close.

 

[HighPSI TSi Guy]

How do you know it is not locking and unlocking under the conditions it's normally supposed to?

 

[samuraitekno]

well i dont think that driving at a constant speed (65mph) should make the ocnverter lock and unlock over and over and continue at any speed. the only time it is not doing it is when i am not on the gas.

 

[HighPSI TSi Guy]

well i dont think that driving at a constant speed (65mph) should make the ocnverter lock and unlock over and over and continue at any speed. the only time it is not doing it is when i am not on the gas.

Is your TPS and TPS plug functioning properly and adjusted properly?

 

[samuraitekno]

yes it is and the problem went away after i disconnected the red wire that controls the lockup solenoid.

 

[rbwtrans]

One of the most common causes of this is overtightening of the filter bolts. That causes the lower portion of the valve body to distort slightly, binding the lock up valve. Another problem is the TCU. They fail just as often as the ECU's for the same reason. The Caps leak and damage the board. Where the caps are located is right next the the speed sensor circuit. If the TCU sees erratic fluctuations from the speed sensors (acid damage on the board) then it will assume that you are speeding up and slowing down. That being said, a speed sensor that is going bad will also do this. A partially clogged filter or cooler will cause the same symptoms. If you would like to test weither the TCU is locking and unlocking the solenoid then a simple light bulb can be put into the circuit.