OBD-II code · Powertrain (generic, extended)

P2524 A/C Request B Circuit High

The A/C request input B reads stuck high — typically a short to battery voltage. The ECM cannot read the switch state, request B is treated as invalid.

Is it safe to drive with P2524?

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

Common causes

  • Most likelyRequest wire shorted to battery voltage
  • Less likelyConnector pins corroded - high contact resistance
  • Less likelySupply wire pinched against B+ source

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
AC Request Input B

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