TC30 - Visually Check Shift Solenoid Harness

Continuous Memory Diagnostic Trouble Codes (DTC) 621 (SS1), 622 (SS2), 641 (SS3) and 643 (TCC) indicate that sometime during the last 80 warm-up cycles, a failure was detected in the respective shift solenoid circuit.

Possible causes:
- Intermittent open/shorted harness.
- Intermittent fault in shift solenoid.

- Check shift solenoid wires between transmission and Powertrain Control Module (PCM).

- Do the shift solenoid wires appear OK?

Yes -- Go to TC31. TC31 - Check Harness and Connectors For Opens or Shorts

No -- Service as necessary. Clear continuous memory. Clearing Diagnostic Trouble Codes

Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)