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.
- Ignition OFF, disconnect the harness connector at the secondary fuel level sensor.
- Ignition ON, verify that the scan tool Fuel Tank Level Remaining parameter display is less than 4 percent.
- If greater than the specified value, test the secondary signal circuit terminal C for a short to ground. If the circuit tests normal, replace the ECM.
- If all circuits test normal, test or replace the secondary fuel level sensor.