TB21 - Check Wiring of Transmission Control Switch Module

- Key "OFF".

- Breakout box installed, Powertrain Control Module (PCM) disconnected.

- Transmission Control Switch Module (TCSM).

- Measure the voltage supply to the TCSM between the red/light green (+) wire and the black white (-) wire.

- Is the voltage greater than 1O.5V?

Yes -- Go to TB22. TB22 - Check Transmission Control Module Switch Input From TCS

No -- Service open circuit or fuse from the TCSM connector to the ignition switch. Remove breakout box. Reconnect all components. Rerun self-test. Quick Test Appendix (Detailed Testing Instructions)