TCC Solenoid Switch Repair

Symptoms:  RPM gauge jumps up and down about 250 RPM and car shudders under mild acceleration or maintaining speed on level or slight incline.  It feels the same as if you are cruising along at constant speed, and then touching the brake with your left foot while keeping your right foot on the gas, thus disengaging the Torque Converter Clutch Solenoid.  I also experienced the problem when on rough/bumpy road.  Basically, the switch is not being securely engaged by the brake pedal so vibrations/bumps cause it to disengage and the Torque Converter disengages from the lock-up state.

Repair:

  1. Remove the 2 sections of plastic panels that cover the area under the steering column.  This includes removing 3 7mm screws and a plastic flare plug.
  2. This will give you access to the 2 switches as you see in the pictures below
  3. Disconnect the wire harnesses from both switches
  4. Remove the upper switch (brake switch) by twisting 1/4 turn and test with ohmmeter on the harness contacts to ensure proper switch functionality.  There are 2 sections to this switch, so check each accordingly with the ohmmeter.
  5. Reinstall brake switch*
  6. Remove the lower switch in the same fashion as the brake switch (this is the TCC Switch), and disconnect the wire harness.  Test with ohmmeter for proper switch functionality.
  7. Reinstall TCC switch*
  8. Plug in wire harnesses to corresponding switches...don't worry, they only fit one way so you can't mess them up.

*Here's the important info you need to know...this is what fixed my problem:

When reinstalling the 2 switches, slightly depress the brake pedal with one hand while inserting the switches and twist 1/4 turn to seat them properly.  You will see a sort of thread on the 2 sides of each switch that actually allows you to seat each switch at the desired depth.  Make sure that both switches are seated and protruding the same distance from the bracket...this ensures both are completely depressed when the brake pedal is released.  See the second picture below to see the properly seated switches while they are fully engaged by the brake pedal.  The first time I reinstalled them I wasn't careful enough and they weren't close enough to equal, so I had to do it again.  The second time, there was sufficient pressure to engage both switches properly and no more problems!

Depressed Brake Pedal Depressed (TCC & Brake Switch Disengaged) Released Brake Pedal Released (TCC & Brake Switch Engaged)