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P2068




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

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 both sensor to determine the fuel level. When the fuel tank is full, the resistances of both fuel level sensors are low. When the fuel tank is empty, the resistances of the fuel level sensors are high. The ECM uses the signal voltages of the primary fuel level sensor and the secondary fuel level sensor 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 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 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

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

With UDD

1. Ignition ON.

2. Verify the fuel level gauge sweeps when performing the scan tool Instrument Cluster Gauge Sweep control function.

• If the fuel level gauge does not sweep
Replace the P16 instrument cluster

• If the fuel level gauge sweeps

3. Verify the low fuel level indicator turns ON and OFF when commanding the scan tool All Indicators control function ON and OFF.

• If the low fuel level indicator does not turn ON and OFF
Replace the P16 instrument cluster

• If the low fuel level indicator turns ON and OFF

4. Verify the scan tool Fuel Level Sensor Left Tank parameter is between 0.5-3.5 V and varies with fuel level.

• If not between 0.5-3.5 V or does not vary with fuel level
Refer to Primary Fuel Level Sensor Malfunction in Circuit/System Testing

• If between 0.5-3.5 V and varies with fuel level

5. Verify the scan tool Fuel Level Sensor Right Tank parameter is between 0.5-3.5 V and varies with fuel level.

• If not between 0.5-3.5 V or does not vary with fuel level
Refer to Secondary Fuel Level Sensor Malfunction in Circuit/System Testing

• If between 0.5-3.5 V and varies with fuel level

6. All OK.

With UDV

1. Ignition ON.

2. Verify the scan tool Fuel Level Sensor Left Tank parameter is between 0.5-3.5 V and varies with fuel level.

• If not between 0.5-3.5 V or does not vary with fuel level
Refer to Primary Fuel Level Sensor Malfunction in Circuit/System Testing

• If between 0.5-3.5 V and varies with fuel level

3. Verify the scan tool Fuel Level Sensor Right Tank parameter is between 0.5-3.5 V and varies with fuel level.

• If not between 0.5-3.5 V or does not vary with fuel level
Refer to Secondary Fuel Level Sensor Malfunction in Circuit/System Testing

• If between 0.5-3.5 V and varies with fuel level

4. All OK.

Circuit/System Testing

Primary Fuel Level Sensor Malfunction

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the A7 fuel pump and level sensor assembly. 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 Fuel Level Sensor Left Tank parameter is greater than 4.8 V.

• If 4.8 V or less

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 greater than 4.8 V

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 Fuel Level Sensor Left Tank parameter is less than 0.2 V.

• If 0.2 V or greater

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 less than 0.2 V

7. Test or replace the A7 fuel pump and level sensor assembly.

Secondary Fuel Level Sensor Malfunction

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B46B fuel level sensor - secondary. 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 Fuel Level Sensor Right Tank parameter is greater than 4.8 V.

• If 4.8 V or less

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 greater than 4.8 V

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 Fuel Level Sensor Right Tank parameter is less than 0.2 V.

• If 0.2 V or greater

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 less than 0.2 V

7. Test or replace the B46B fuel level sensor - secondary.

Component Testing

1. Ignition OFF, remove the appropriate 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 appropriate 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 Service and Repair

* Control Module References Control Module References for engine control module or instrument cluster replacement, programming, and setup

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