P2266 OBD-II Trouble Code: Low Voltage in Water in Fuel Sensor

P2266 code definition

The P2266 code is set when low voltage is detected in the WIF (Water in Fuel) Sensor circuit at the Engine Control Module (ECM). Other fuel system codes may set along with P2266.

What the P2266 code means

P2266 is the generic OBD-II code for Water in Fuel Sensor Circ Low. This code indicates a low voltage signal in the WIF circuit.

What causes the P2266 code?

A variety of conditions may trigger a vehicle to set this code:

• The WIF Sensor Signal circuit may be shorted to the ground.
• The WIF Sensor Signal circuit may be shorted to the sensor ground.
• There may be water or other contaminants in the WIF Sensor.
• The ECM (Engine Control Module) may be faulty.

What are the symptoms of the P2266 code?

The P2266 code may cause no symptoms at all, or the vehicle may misfire, hesitate, or fail to start.

How does a mechanic diagnose the P2266 code?

Mechanics may use a variety of procedures in diagnosing the cause of a P2266 code, beginning with using a scan tool to verify that the code is active. If it is, the next step is to measure the voltage between the Water in Fuel Sensor Signal circuit and Water in Fuel Sensor Ground circuit of the harness connector to ensure that it measures at the correct voltage. Depending upon the results of the voltage test, the technician may replace the WIF Sensor, or go on to test voltage in other parts of the system, or the Engine Control Module itself. Appropriate repairs or replacement may then be made.

Common mistakes when diagnosing the P2266 code

If proper procedures aren’t followed, the source of the problem could be missed due to the fact that there are several components involved in the functioning of the WIF Sensor. Each step in the process must be followed in order to determine whether the fuel is being contaminated, or there is a fault in the wiring, connector, or ECM.

What repairs can fix the P2266 code?

Repairing the P2266 code may involve a variety of steps, depending upon the source of the fault:

• A scan tool is used to verify the code, then the codes are reset and the vehicle is road tested to determine if the code comes back.
• The voltage between the WIF Sensor Signal circuit and the WIF Sensor Ground circuit is tested, and if it measures correctly, the Water In Fuel Sensor may be replaced.
• Resistance between the WIF Sensor Signal circuit and the harness connector ground is measured, and repaired if there is a short.
• If resistance measures correctly, the ECM may be replaced.

Additional comments for consideration regarding the P2266 code

Sensors frequently demonstrate intermittent condition behaviors, only occasionally setting the P2266 code. This can make diagnostics a challenge, because it can be difficult to determine the source of the fault if the problem is not consistent. Vehicle sensors are typically considered part of regular maintenance procedures and should be replaced according to the manufacturer’s recommendations at routine intervals in order to prevent further potential damage.

Need help with a P2266 code?

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