Powertrain, generic (extended)

P2536 Ignition Switch Accessory Position Circuit

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P2536 is the general fault of the accessory input, the signal that is live when the key or start button is in the accessory position and that on many vehicles also acts as a wake-up line between body and powertrain modules. The code does not say whether the line is open, low or high, only that its state cannot be used. No manufacturer documents P2536 publicly. The best analogue is P2537, which GM evaluates in engine and transmission modules; in bulletin PIT5308 GM explains that the ECM and TCM receive a 12 V accessory wake-up from the body module on circuit 5985. A faulty accessory line can disable functions that need modules awake with the engine off, such as remote start. Low and high levels are P2537 and P2538.

Likely causes

Fault in the accessory feed or wake-up output of the body module
Loose or corroded terminal on the accessory line
Worn accessory contact in the ignition switch

Symptoms

  • Remote start or key-off functions not working
  • Accessories behave inconsistently in the accessory position

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€10–400
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

ignition switchwiring harness

Related codes

P2537P2538P2530P2533

References: law.cornell.edu, static.nhtsa.gov, gsi.ext.gm.com.