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Displays and Gauges (CZ2)





DTC P0461-P0464, P2066, P2067, or P2068 (CZ2)

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 P0461
- Fuel Level Sensor Performance

DTC P0462
- Fuel Level Sensor 1 Circuit Low Voltage

DTC P0462
- Fuel Level Sensor Circuit Low Voltage

DTC P0463
- Fuel Level Sensor 1 Circuit High Voltage

DTC P0463
- Fuel Level Sensor 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 serial data to the body control module (BCM). The BCM then sends the fuel level percentage via serial data 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 change in fuel level of less than a specified amount (typically 3-10 L or 0.8-2.6 gal) over a specified driving distance (typically 240-320 km or 150-200 miles).

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 Sunshade - Left

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, 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.

• If the fuel level gauge sweeps

2. 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 does not turn ON or OFF as commanded
Replace the P16 Instrument Cluster.

• If the low fuel level indicator turns ON and OFF as commanded

3. Observe the scan tool ECM Fuel Level Sensor parameter. The reading should be 0.5-3.5 V and vary with fuel level.

• If the reading does not vary with fuel level
Refer to Circuit/System Testing.

• If the reading varies with fuel level

4. All OK.

Circuit/System Testing

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate fuel level sensor. It may take up to 2 minutes for all vehicle systems to power down.

2. Test for less than 10 ohms between the low reference circuit terminal 3 and ground.

• If 10 ohms or greater

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.

2. Test for less than 2 ohms in the low reference circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K20 Engine Control Module.

• If less than 10 ohms

3. Ignition ON.

4. Verify the scan tool Remaining Fuel In Tank parameter is less than 5%.

• If 5% or greater

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.

2. Test for infinite resistance between the signal circuit terminal 4 and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance, replace the K20 Engine Control Module.

• If less than 5%

5. Install a 3 A fused jumper wire between the signal circuit terminal 4 and the low reference circuit terminal 3.

6. Verify the scan tool Remaining Fuel In Tank is greater than 90%.

• If 90% or less

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.

2. Test for less than 1 V between the signal circuit and ground.

• If 1 V or greater, repair the short to voltage on the circuit.

• If less than 1 V

3. Ignition OFF

4. Test for less than 2 ohms in the signal circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K20 Engine Control Module.

• If greater than 90%

7. Test or replace the appropriate fuel level sensor.

Component Testing

1. Ignition OFF, remove the fuel level sender.

2. Sweep the fuel level sensor through its full range of motion while measuring resistance between the signal terminal 4 and the low reference terminal 3.

3. Test for a minimum resistance value of 37-43 ohms and a maximum value of 245-255 ohms without any spikes or dropouts.

• If minimum resistance is not 37-43 ohms, maximum resistance is not 245-255 ohms, or if there are any spikes or dropouts
Replace the fuel level sensor.

• If minimum resistance is 37-43 ohms, maximum resistance is 245-255 ohms, and if there are no spikes or dropouts

4. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Fuel Level Sensor Replacement Fuel Level Sensor Replacement for LHU

* Fuel Level Sensor Replacement Fuel Level Sensor Replacement for LEA or LUK

* Control Module References Control Module References for the ECM replacement, programming and setup

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