Circuit Description

Fuel level sender changes resistance based on fuel level. Powertrain Control Module (PCM) monitors signal circuit of fuel level sender in order to determine fuel level. When fuel tank is full, sender resistance is high and PCM senses a high signal voltage. When fuel tank is empty, sender resistance is low and PCM senses a low signal voltage. PCM uses signal circuit of fuel level sender in order to calculate the total remaining fuel percentage in the tank. PCM sends fuel level percent via class 2 serial data circuit to Instrument Panel Cluster (IPC) in order to control fuel gauge. Fuel level information is also used for misfire and EVAP diagnostics. This DTC sets when fuel level signal is greater than 99 percent for more than 20 seconds. When DTC is in effect, the following occurs:

• Fuel gauge defaults to EMPTY.
• LOW FUEL indicator illuminates.
• PCM records operating conditions at time the diagnostic fails. PCM displays failure information in the FAILURE RECORDS on scan tool.