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P2AAF

Diesel Fuel Presence Sensor Circuit High

Voltage on the diesel fuel presence sensor signal line is above the expected window. Wire shorted to B+ or sensor open.

  • Check engine light: Yes
  • Emissions related: Yes
  • Repair difficulty: easy

Common causes

Ordered by how often each turns out to be the cause.

  • Signal wire shorted to B+Common
  • Open sensorPossible
  • Connector pins corroded - high contact resistanceLess likely

Parts involved

  • Diesel Fuel Presence Sensor
  • Wiring Harness
  • ECM

P2AAF is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.