Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. 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.