Circuit Description

WARNING: This page is about a different car, the 2010 Pontiac G5 and 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

The fuel level sensor changes resistance in response to the fuel level. The engine control module (ECM)/powertrain control module (PCM) monitors the signal circuit of the fuel level sensor in order to determine the fuel level. When the fuel tank is full, the fuel level sensor resistance is low and the ECM/PCM senses a low signal voltage. When the fuel tank is empty, the fuel level sensor resistance is high and the ECM/PCM senses a high signal voltage. The ECM/PCM uses the signal circuit of the fuel level sensor in order to calculate the percentage of fuel remaining in the tank. The ECM/PCM sends the fuel level information via the serial data circuit to the body control module (BCM). The BCM sends the fuel information to the instrument panel cluster via the serial data circuit in order to control the fuel gauge and display the fuel level.

This diagnostic tests for an intermittent fuel level sensor signal. If a change in fuel level is detected, the engine-off natural vacuum small leak test DTC P0442 is aborted due to a refueling event. Before aborting DTC P0442 a refueling event test is executed to confirm that a refueling event has occurred. If refueling is confirmed, the test is considered a pass. Otherwise, the DTC P0464 sets indicating an intermittent signal problem.