P2538 code meaning
Ignition Switch Accessory Position Circuit High
What P2538 means
P2538 is set when the accessory input reads high in a state where it should be inactive, for instance once the vehicle is switched off and the body module should have released the line. Backfeed from an aftermarket device, a stuck accessory relay or a wire touching a battery feed are the obvious causes. A permanently high accessory line can keep modules awake and drain the battery. No manufacturer publishes P2538; the documented counterpart is GM's P2537, judged on the accessory wake-up signal against propulsion status, and GM's PIT5308 notes that some voltage after key-off is normal while the body module is still awake, so timing matters before calling the line faulty. P2536 is the general and P2537 the low fault.
P2538 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2538
- Battery drain while parked
- Radio or accessories stay on after key-off
Common causes of P2538
- PossibleBackfeed from aftermarket equipment connected to the accessory line
- PossibleAccessory relay stuck closed
- Less likelyAccessory wire chafed against a battery feed
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Ignition switchWiring harness
What each part of P2538 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 5 | Area: vehicle speed, idle control and auxiliary inputs. |
| 38 | The exact fault in that area. |
What to do next
- Note P2538 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2538
What does P2538 mean?
P2538 means "Ignition Switch Accessory Position Circuit High". P2538 is set when the accessory input reads high in a state where it should be inactive, for instance once the vehicle is switched off and the body module should have released the line. It is a generic code, so it means the same on every make.
Is it safe to drive with P2538?
P2538 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will P2538 fail an emissions test?
P2538 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P2538 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2538 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.