OBD-II code · Powertrain (generic, extended)

P2A79 Alternative Fuel Hydraulic Pump Pressure Sensor Circuit Intermittent/Erratic

The alternative fuel hydraulic pump pressure sensor signal drops out or jumps intermittently. Loose connector or noisy ground.

Is it safe to drive with P2A79?

The car may go into limp mode (reduced power). Get it diagnosed before a long trip.

Common causes

  • Most likelySensor connector not seated
  • PossibleNoisy ground reference
  • Less likelyConnector with intermittent contact under vibration

Repair at a glance

Difficulty
Medium
DIY friendly
Best left to a mechanic
Typical labour
1–4 h
Emissions test
Likely to fail
Parts involved
Alt Fuel Hyd Pump Pressure Sensor, Wiring Harness, Afcm

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.