P2066
Fuel Gauge Malfunction - DTC P0461-P0464 or P2066-P2068
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P0461
-
Fuel Level Sensor 1 Performance
DTC P0462
-
Fuel Level Sensor 1 Circuit Low Voltage
DTC P0463
-
Fuel Level Sensor 1 Circuit High Voltage
DTC P0464
-
Fuel Level Sensor 1 Circuit Intermittent
DTC P2066
-
Fuel Level Sensor 2 Performance
DTC P2067
-
Fuel Level Sensor 2 Circuit Low Voltage
DTC P2068
-
Fuel Level Sensor 2 Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
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.
Conditions for Running the DTC
* The engine is running.
* The system voltage is between 11-16 V.
Conditions for Setting the DTC
P0461 or P2066
* The ECM detects a difference between the fuel consumed by the engine and change of the fuel level signal of less than 1 L (0.26 gal) over a range of 30 L (7.92 gal) or 45.6% of the primary fuel tank.
* The above condition is present for about 300 seconds.
P0462 or P2067
* The signal voltage is less than 0.25 V.
* The above conditions must be met for 5 seconds.
P0463 or P2068
* The signal voltage is greater than 4.7 V.
* The above conditions must be met for 5 seconds.
P0464
* The fuel level change is greater than 10%.
* The above conditions must be met for 30 seconds.
* DTC P0464 runs and fails 2 out of 3 test cycles.
Action Taken When the DTC Sets
* P0461, P0462, P0463, P0464, P2066, P2067 and P2068 are Type B DTCs.
* The fuel gauge defaults to empty.
* The low fuel indicator illuminates.
Conditions for Clearing the DTC
* P0461, P0462, P0463, P0464, P2066, P2067 and P2068 are Type B DTCs.
* The DTC becomes history when the conditions for setting the DTC are no longer present.
* The history DTC clears after 40 malfunction-free warm-up cycles.
Reference Information
Schematic Reference
Instrument Cluster Schematics Instrument Cluster Schematics
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly - Primary
Description and Operation
Instrument Cluster Description and Operation Instrument Cluster
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
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 gauge sweeps from its low to high position.
• If the fuel level gauge does not sweep, replace the P16 instrument cluster.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the appropriate fuel level sensor.
2. Test for less than 10 ohms 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. Remove the fuel level sensor.
5. Verify there is no damage to any component in the surrounding area of the fuel level sensor that would inhibit the mechanical range of the sensor.
• Repair or replace any damaged component as necessary.
6. If all circuits test normal, replace the appropriate fuel level sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Fuel Level Sensor Replacement - Left Side Fuel Level Sensor Replacement - Left Side for the LLT engine
* Fuel Level Sensor Replacement - Right Side Fuel Level Sensor Replacement - Right Side for the LLT engine
* Fuel Level Sensor Replacement - Left Side Fuel Level Sensor Replacement - Left Side for the L99 or LS3 engine
* Fuel Level Sensor Replacement - Right Side Fuel Level Sensor Replacement - Right Side for the L99 or LS3 engine
* Control Module References Control Module References for the ECM replacement, programming and setup