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 place the transmission range selector in D6.
- Observe the TFP Switch 3 parameter while commanding 1st gear and then commanding 2nd gear with the scan tool. The TFP Switch 3 should transition from Low in 1st gear to High in 2nd gear.
- If the TFP Switch 3 parameter state does not change, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection .
- If no concerns are found, replace the control solenoid (w/body and TCM) valve assembly.