OBD-II code · Powertrain (generic, extended)

P2507 ECM/PCM Power Input Signal Low

The ECM/PCM switched-battery input reads below threshold while the ignition is on. Either the main relay does not close, the supply wire is broken or shorted to ground, or the battery is too low. Engine usually fails to start until the input recovers.

Is it safe to drive with P2507?

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

Common causes

  • Most likelyMain relay does not pull in
  • PossibleOpen supply wire
  • PossibleSeverely discharged battery

Repair at a glance

Difficulty
Medium
DIY friendly
Best left to a mechanic
Typical labour
0.4–2 h
Emissions test
Usually unaffected
Parts involved
Main Relay, Power Input Wire, Battery

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