Captiva

Fuel Gauge Malfunction - DTC P0461-P0464 or P2066-P2068

E85 Fuel Applications

For regular unleaded fuel the ECM monitors a constant signal. When the vehicle has approximately 20% or greater ethanol for E85 applications, the ECM controls a pulse cycle signal where it monitors the signal and calculates the fuel level percentage only during the on pulse of approximately 100 ms.

Single Fuel Tank Applications

For a single tank application, the fuel level sensor changes resistance in response to the fuel level. The engine control module (ECM) monitors the signal circuit of the fuel level sensor and the type of fuel in order to determine the fuel level.

When the fuel tank is full, the sensor resistance is low and the ECM senses a low signal voltage. When the fuel tank is empty, the sensor resistance is high and the ECM senses a high signal voltage. The ECM uses the signal circuit of the fuel level sensor in order to calculate the percentage of remaining fuel in the tank. The ECM sends the fuel level percentage via the serial data circuit to the instrument cluster in order to control the fuel gauge.

Dual Fuel Tank Applications

The primary fuel level sensor and, the secondary fuel level sensor change resistance based on fuel level. The engine control module (ECM) monitors the signal circuits of the primary fuel level sensor and the secondary fuel level sensor in order to determine the fuel level. When the fuel tank is full, the resistances of both fuel level sensors are low and the ECM senses a low signal voltage on both the signal circuits of the primary fuel level sensor and the secondary fuel level sensor. When the fuel tank is empty, the resistances of the fuel level sensors are high and the ECM senses a high signal voltage. The ECM uses the signal circuits of the primary fuel level sensor and the secondary fuel level sensor in order to calculate the percentage of remaining fuel in the tank. The ECM sends the fuel level percentage via the serial data circuit to the instrument cluster in order to control the fuel gauge.

P0461 or P2066

P0462 or P2067

P0463 or P2068

P0464

The following engines have two fuel level sensor

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Instrument Cluster Description and Operation

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, observe the scan tool ECM - Fuel Level Sensor parameters. The reading should be between 0.5-3.5 V and vary with fuel level.
2. Ignition ON, perform the Instrument Cluster Gauge Sweep test with the scan tool, verify that the fuel level gage sweeps from its low to high position

⇒	If the fuel level gauge does not sweep, replace the P16 instrument cluster.

3. Command the All Indicators test ON and OFF with the scan tool, verify that the low fuel level indicator turns ON and OFF.

⇒	If the low fuel level indicator always stays on or always off, replace the P16 instrument cluster.

1. Ignition OFF, disconnect the harness connector at the appropriate fuel level sensor.
2. Test for less than 10 Ω at the low reference circuit terminal 3.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 engine control module.

3. Ignition On, test for 4.8-5.2 V between the signal circuit terminal 4 and ground.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.

4. If all circuits test normal, replace the appropriate fuel level sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.