OBD-II code · Powertrain (generic, extended)

P25C3 Alternative Fuel Disable Signal Circuit Low

The disable feedback signal sits below its valid window. Usually a short to ground or an open pull-up that lets the input float low.

Is it safe to drive with P25C3?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyFeedback wire shorted to ground
  • Less likelyOpen pull-up resistor in the controller input
  • Less likelyConnector pins corroded - high contact resistance

Repair at a glance

Difficulty
Medium
DIY friendly
Best left to a mechanic
Typical labour
0.8–2 h
Emissions test
Usually unaffected
Parts involved
Alt Fuel Control Module, Wiring Harness

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