4T60E TCC Problem?

I have a '96 buick century. It shifts hard from sceond to third, and sometimes going up a hill it vibrates downshifting from third to second. The scanner says TCC stuck on. Using an Ohmmeter and back probing the connector, all solenoids test in the 23 ohm range, which is acceptable, except the TCC PWM solenoid, which reads 3 ohms. Its acceptable range is 10 to 15 ohms. Could this little device be causing all this problem? The TCC ON/OFF solenoid tests okay, so is there probably something else wrong besides just the PWM? Or is the solenoid possibly just stuck closed? Finally, is it possible to get the side cover off without removing the transaxle?

Welcome to AF.

Based on your testing it looks like the TCC-PWM solenoid is your problem. The coil resistance is abnormal based on what you are saying. If it is stuck on then it is probably stuck closed.

It is next to impossible to remove the side cover to replace a solenoid on the valve body without repositioning which normally includes supporting the engine and tranny and dropping it down with the complete subframe.