TE10 - Attempt To Generate DTC 66 or 638

Diagnostic Trouble Code (DTC) 637 indicate the Transmission Fluid Temperature (TFT) sensor output is greater than Self-Test maximum value of 4.8 volts.

Possible causes:
- Fluid levels not to specification.
- Damaged TFT sensor.
- Open harness circuit(s).
- Damaged Powertrain Control Module (PCM).

- Key "OFF".

- Disconnect transmission connector at TFT sensor. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

- Insert a jumper wire from the TFT circuit to SIG RTN circuit at transmission vehicle harness connector.

- Run Key On Engine Off Self-Test. Quick Test Appendix (Detailed Testing Instructions)

- Is DTC 638 present?

NOTE: Disregard any other DTC generated at this time. If no DTCs are generated (module not responding), go to TE12. TE12 - Check TFT Circuit For Short to VPWR

Yes -- Remove jumper wire.
Refer to Transmission and Drivetrain for TFT sensor service.

No -- Remove jumper wire. Go to TE11. TE11 - Check Continuity of TFT and SIG RTN Circuits