FixVault

Circuit/System Testing

WARNING: This page is about a different car, the 2007 Chevrolet Monte Carlo and 2007 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at the fuel level sensor. Install a signal generator and instrument panel tester between the signal circuit and the low reference circuit.
  2. Ignition ON, vary the resistance on the signal generator from 40-250 ohms. Verify that the scan tool Fuel Level Sensor parameter displays the correct voltage levels as the resistance is varied from 40 - 250 ohms. Refer to Fuel Level Specifications .
    • If the fuel level sensor voltage is incorrect, test the signal circuit and the low reference circuit for an open/high resistance. If the circuits test normal, replace the ECM.
  3. If all circuits test normal, test or replace the fuel level sensor.