One quick strategy is to pull and visually check the TCM fuse. The TCM fuse is in the main fuse block and is probably 10 amps. If the fuse is blown, that is confirmation but the faulty fuse means there is a short circuit in the TCM and/or wiring that would have to be traced and repaired.
What causes a TCM to fail?
Damage to the control module can be caused by voltage overload, when there is a short in the solenoid or actuator circuit; when water causes the circuits to get shorted out; or vibration and thermal stress.
What does a bad TCM look like?
Trouble shifting into higher gear. Trouble downshifting. Getting stuck in the same gear. Poor fuel economy.
Does a used TCM need to be reprogrammed?
Re: Used TCM Need Reprogramming or Not? Short answer is NO. No programing is required if the new TCM came out of a working car of the same elk as yours.
Related Question How do I know if my TCM is bad?
How do I check my transmission?
Pull out the dipstick, wipe it clean, replace it slowly, and then pull it back out. Check the fluid level—how high the fluid comes up on the dipstick—against the "full" and "low" or "fill" marks on the dipstick. The color of transmission fluid can tell you a lot about the health of your car's transmission.
What is a TCM relay?
The TCM power relay control circuit exists between the battery and the transmission control module, and protects the transmission's computer from voltage irregularities. It also allows for a self test when the ignition key is turned on.
How much is a TCM module?
How Much Does a New Transmission Control Module Cost? A replacement transmission control module can cost you anywhere between $100 and $400. Expect to spend around $50 to $200 on labor costs. Parts and labor combined, installing the new part will cost you in the range of $150 to $600.