Fuel Level Sensor "B" Circuit High
P2068 indicates the fuel level sensor B circuit is receiving a voltage signal that is higher than expected. This typically means the sensor circuit has an open connection, a short to battery voltage, or a ground path problem that prevents the ECU from reading accurate fuel level information.
What You Might Notice
- Check Engine Light (MIL) illumination
- Fuel gauge fluctuates abnormally or reads empty when tank has fuel
- Fuel gauge reads full when tank is not full
- Low fuel warning light illuminates prematurely
- Fuel level gauge becomes stuck at one position
Most Common Causes
- 1
Open or shorted signal circuit
The wiring from the fuel sender to the ECU is open (broken connection) or shorted to battery voltage, causing the high voltage reading that triggers the code.
- 2
Ground circuit failure
The ground connection for the fuel sender is open or has high resistance due to corrosion, rust, or a missing ground strap on the fuel tank, preventing proper voltage return.
- 3
Faulty fuel level sensor
The fuel sender unit inside the fuel tank has failed internally or the resistor element is damaged, sending an out-of-range signal to the instrument cluster.
- 4
Fuel tank or wiring damage
Physical damage to the fuel tank, sender connector, or the wiring harness has compromised the circuit integrity and signal transmission.
How to Diagnose It
- 1
Check Open or shorted signal circuit — The wiring from the fuel sender to the ECU is open (broken connection) or shorted to battery voltage, causing the high voltage reading that triggers the code.
- 2
Check Ground circuit failure — The ground connection for the fuel sender is open or has high resistance due to corrosion, rust, or a missing ground strap on the fuel tank, preventing proper voltage return.
- 3
Check Faulty fuel level sensor — The fuel sender unit inside the fuel tank has failed internally or the resistor element is damaged, sending an out-of-range signal to the instrument cluster.
- 4
Check Fuel tank or wiring damage — Physical damage to the fuel tank, sender connector, or the wiring harness has compromised the circuit integrity and signal transmission.
How to Fix It
- 1
Inspect and repair wiring harness
Visually inspect the fuel sender wiring harness from the fuel tank to the ECU for breaks, corrosion, loose connectors, or damage. Repair or replace damaged sections and ensure all connections are clean and tight.
- 2
Clean and restore ground connections
Remove the fuel tank ground strap and clean both connection points with a wire brush to remove corrosion and rust. Reinstall the ground strap securely and ensure a solid metal-to-metal connection on both ends.
- 3
Replace fuel level sensor
Access the fuel tank and remove the fuel sender unit. Install a new fuel level sensor assembly and reconnect the wiring harness, ensuring the connector is fully seated.
- 4
Check instrument cluster and ECU connectors
Inspect the ECU connector and instrument cluster connections for corrosion or loose pins. Clean contacts with electrical contact cleaner and reseat all connectors firmly to ensure proper signal reception.
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