Powertrain, generic (extended)

P2266 Water in Fuel Sensor A Circuit Low

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P2266 is set when the signal line of water-in-fuel sensor A stays below its valid range, typical of a grounded signal wire or of a conductive path that should not be there. Ford documents the code on 2017 and 2018 Super Duty trucks with the 6.7L diesel built up to 15 March 2018: bulletin 18-2133 links P2266, P2269 and P1140 with a lit water-in-fuel lamp to water entering connector C3080 at the sensor, which sits between tank and frame rail. The procedure checks the sensor across pins 1 and 2 for 795 to 815 kOhm, replaces it if out of range, then dries and wraps the connector. As water itself conducts, a wet plug can fake both a low circuit and a water alarm. P2267 is the high side, P2264 the general circuit code.

Likely causes

Water intrusion into the sensor connector bridging signal and ground
Sensor with internal resistance outside specification
Signal wire chafed against the frame and shorted to ground

Symptoms

  • Water-in-fuel lamp on although no water is in the separator
  • Often stored together with P2269

Repair estimate

DifficultyEasyDIY possible
Parts and labour€20–200
Time0.3–1 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

water in fuel sensorfuel filter

Related codes

P2267P2264P2268P2269

References: static.nhtsa.gov, patents.google.com, law.cornell.edu.