OBD-II code · Powertrain (generic, extended)
P2538 Ignition Switch Accessory Position Circuit High
The ACC input reads stuck high — short to battery voltage. The ECM cannot detect when the operator releases the switch from ACC, accessory power timeouts do not work.
Is it safe to drive with P2538?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyACC 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
- 0.5–2 h
- Emissions test
- Usually unaffected
- Parts involved
- Ignition Switch, Wiring Harness
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.