Severity and Symptoms
Severity depends on the failure. In case of mechanical failure: severe. In case of electrical failure, less severe, which the PCM can compensate for. Compensation typically means the fuel gauge reads empty or full all the time.
Symptoms of an engine code P2069 may include:
- Malfunction Indicator Light (MIL) illuminated
- Perceived decrease in fuel economy
- Reduced distance to empty mileage
- Incorrect fuel level on the gauge in the instrument cluster – always reads incorrectly
Potential Causes
Typically, the causes for this code to set are as follows:
- Intermittent open in the signal circuit to the FLS sensor – possible
- Intermittent short to voltage in the signal circuit to the FLS sensor – possible
- Intermittent short to ground in the signal circuit to the FLS sensor – possible
- Failed FLS sensor/float arm mechanically stuck – probable
- Failed PCM – unlikely
Diagnostic and Repair Procedures
A good starting point is always to search for a Technical Service Bulletin (TSB) for your specific vehicle. The vehicle manufacturer may have a PCM flash/reprogramming to address this issue, and it’s worth checking before discovering you’ve taken a long/wrong path.
Next, locate the Fuel Level Sensor (FLS) on your specific vehicle. This sensor is usually mounted in the fuel tank or possibly even on top of the fuel tank module/fuel pump. Once located, visually inspect the connector and wiring. Look for scratches, rubbing, bare wires, burns, or melted plastic. Disconnect the connector and carefully inspect the terminals (the metal parts) inside the connector. See if they appear burnt or have a greenish tint indicating corrosion. Use electrical contact cleaner and a plastic bristle brush if terminal cleaning is necessary. Let it dry and apply electrical grease where the terminals make contact.
If you have a scan tool, clear the diagnostic codes from memory and see if the P2069 code returns. If it does not, the connections were likely your problem.
This is the most common area of concern for this code, as fuel tank connections have the highest number of corrosion issues.
If the P2069 code returns, we will need to test the FLS sensor and its associated circuits. With the key off, disconnect the electrical connector from the FLS sensor. Connect a black wire from the Digital Voltmeter (DVOM) to the ground or low reference terminal at the FLS sensor wiring harness connector. Connect the red wire from the Digital Voltmeter to the signal terminal at the FLS sensor wiring harness connector. Turn the key to the engine off position. Check manufacturer specifications; the voltmeter should read 12 volts or 5 volts. Wiggle the connections to see if they change. If the voltage is incorrect, repair the power or ground wire or replace the PCM.
If the previous test was successful, connect one wire of an ohmmeter to the signal terminal of the FLS sensor and the other wire to the ground or low reference terminal of the sensor. The ohmmeter reading should not be zero ohms nor infinite. Check manufacturer specifications for sensor resistance to accurately test resistance at fuel level (1/2 tank of fuel may read 80 ohms). Wiggle the fuel level sensor connector while monitoring the resistance. If the ohmmeter readings do not pass, replace the FLS.
If all previous tests have passed and you continue to get a P2069, this would most likely indicate a faulty FLS sensor, although a faulty PCM cannot be ruled out until the FLS sensor has been replaced. If in doubt, seek assistance from a qualified automotive diagnostician. PCMs must be programmed or calibrated to the vehicle to be installed correctly.