P2068 — Fuel Level Sensor “B” Circuit High #

The code description may vary depending on the vehicle manufacturer.

• Fuel Level Sensor “B” Circuit High Input — General (SAE)
• Fuel Level Sensor 2 Circuit High — General Motors (GM)
• Fuel Tank Level Sensor B Circuit High — Nissan
• Fuel Sender B Circuit High — Ford

Summary of DTC P2068 #

P2068 is a diagnostic trouble code (DTC) that indicates the engine control module (ECM) or powertrain control module (PCM) has detected a high voltage signal in the Fuel Level Sensor “B” circuit. The fuel level sensor monitors the amount of fuel in the tank and provides this information to the vehicle’s fuel gauge and sometimes other systems. The “B” designation refers to a secondary or auxiliary fuel level sensor, commonly found in vehicles with complex fuel tanks or dual-tank systems. A “circuit high” fault means the sensor is sending a voltage higher than the expected range, which the computer interprets as an anomaly. This code can affect your fuel gauge accuracy and, in rare cases, influence engine or emissions performance.

Common Symptoms for Code P2068 #

When the P2068 code is active, you might notice several symptoms that can range from minor annoyances to more significant inconveniences. These symptoms primarily relate to incorrect fuel readings, which can impact your confidence in your vehicle’s displayed range and fuel level.

• Fuel gauge stuck at “Full” or “Empty”
• Erratic or fluctuating fuel level readings
• Illuminated check engine light (CEL/MIL)
• Low fuel warning light comes on unexpectedly
• Possible fuel range miscalculation on the driver display

Probable Causes for Code P2068 #

Most causes of P2068 relate to the sensor itself or issues within its circuit. Understanding these causes helps prioritize diagnostics and repairs:

1. Faulty fuel level sensor “B” (due to wear, corrosion, or manufacturing defect)
2. Open or shorted wiring harness between sensor and PCM/ECM
3. Poor electrical connections or corroded terminals at the sensor or module
4. Damaged fuel sender unit inside the tank
5. PCM/ECM software or hardware malfunction (rare)

Step-by-Step Diagnostic for Code P2068 #

A thorough and methodical approach is key for diagnosing P2068. Here’s a proven step-by-step guide:

• Verify the code with a compatible OBD-II scanner and check for other related codes.
• Inspect the fuel level sensor wiring and connectors for visible damage or corrosion.
• Test the sensor circuit voltage and ground with a digital multimeter, comparing to OEM specifications.
• Check the integrity and operation of the fuel sender unit inside the tank (may require tank removal).
• Test the sensor resistance (ohms) while moving the float arm manually, if accessible.
• Clear the code and road test to see if it returns after repairs or adjustments.
• If no fault found, consider PCM/ECM diagnostics or reprogramming as a last resort.

Possible Repairs for Code P2068 #

Repairs for P2068 should directly address the identified cause. The most effective fixes include:

• Replace the faulty fuel level sensor “B” or the entire sender unit
• Repair or replace damaged wiring and connectors in the sensor circuit
• Clean corroded electrical terminals and apply dielectric grease
• Reflash or replace the PCM/ECM if proven defective (very rare scenario)

Is It Safe to Drive with Code P2068? #

Limited — While P2068 typically does not affect drivability or engine performance, it can compromise your ability to accurately monitor fuel level. This increases the risk of unexpectedly running out of fuel and being stranded. If you rely on long-range driving or have little margin for error, address this code promptly.

Vehicles Most Commonly Affected by Code P2068 #

P2068 is most frequently encountered in vehicles with dual fuel tanks or complex fuel sender designs, often found in trucks, SUVs, and some performance cars. These models may include:

• Chevrolet Silverado and GMC Sierra (especially with dual tanks)
• Ford F-Series Super Duty trucks (with auxiliary tanks)
• Nissan Armada and Titan
• Ram 2500/3500 trucks
• Some BMW and Mercedes-Benz models with saddle-style fuel tanks

Common Mistakes & Best Practices for Code P2068 #

Incorrectly diagnosing or repairing P2068 can lead to frustration and unnecessary expense. Avoid these pitfalls:

• Replacing the sensor before checking wiring and connections
• Ignoring the possibility of a poor electrical ground
• Overlooking tight or corroded connectors in harsh climates
• Neglecting to clear codes and retest after repairs
• Failing to consult OEM wiring diagrams for accurate pin identification

Express FAQ for Code P2068 #

Q: Does P2068 mean my fuel pump is failing?
A: Not directly. This code relates to the fuel level sensor circuit, not the pump itself. However, in rare cases, a faulty sender unit (which sometimes includes the pump) could be at fault.

Q: Can a bad P2068 code cause my vehicle to stall?
A: Not under normal circumstances. This code affects the fuel level reading, not actual fuel delivery. But running out of fuel due to a false gauge reading can ultimately cause a stall.