Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Cadillac Escalade EXT. 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 5 parameter while commanding 1st gear and then commanding 2nd gear with the scan tool. The TFP switch 5 should transition from low in 1st gear to high in 2nd gear.
- If the TFP Switch 5 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.