B: Transmission Fluid/Oil Temperature (TFT/TOT) Sensor

PINPOINT TEST B: DIAGNOSTIC TROUBLE CODES 636: TOT HIGHER/LOWER THAN EXPECTED, 637: TOT ABOVE MAX VOLTAGE /-40F INDICATED, 638: TOT BELOW MIN VOLTAGE /+290F INDICATED, 657: TRANSAXLE OVERTEMP CONDITION


This Pinpoint Test is designed to diagnose the transmission oil temperature (TOT) sensor electrical system ONLY.
To prevent replacement of good components, note that the following areas may be at fault:
- Engine - Performance, cooling
- Electrical - Battery, wiring harnesses
- Transmission - Internal transmission components, cooling, fluid

This Pinpoint Test is designed to diagnose the following components:
- Transmission Wiring Harness, TOT, SIGNAL RETURN
- Powertrain Control Module (PCM)

Refer to the following schematic and charts when performing the Pinpoint Test steps.