Circuit/System Testing

WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Ensure the TFT is near the temperature displayed in the Failure Records.
Start the engine and observe the TFP Switch 1 parameter while moving the range selector lever from Park to Reverse. The TFP Switch 1 should transition from Hi in Park to Low in Reverse.
- If the TFP Switch 1 parameter does not change, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection .
- If no concerns are found, replace the control solenoid valve and TCM assembly.