P2537 code meaning
Ignition Switch Accessory Position Circuit Low
Powertrain system Generic code P25xx codes Check engine light
What P2537 means
P2537 reports that the accessory or accessory wake-up input sits low where a high level is expected. GM documents it in detail: on the 2016 Volt the ECM fails it when the accessory input is false while the propulsion system has been active for more than 0.5 s; it is a Type B fault over 2 trips, and the 6-speed TCM tables evaluate the same input with no MIL. GM bulletin PIT5308 for 2014–2015 Silverado, Sierra, Tahoe, Yukon, Suburban and Escalade links P2537 to remote start, and a power liftgate that only works with the ignition on, because ECM and TCM do not get the 12 V accessory wake-up from the BCM on circuit 5985; that wire is checked with a voltmeter, not a test lamp. A diesel follow-up (PIT5308A) adds a blower that keeps running after shutdown.
P2537 at a glance
- Check engine lightYes, usually on
- 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 P2537
- Remote start inoperative
- Power liftgate works only with ignition on
- Blower may keep running after engine shutdown (diesel)
Common causes of P2537
- Most likelyOpen or high-resistance accessory wake-up circuit between BCM and ECM/TCM
- PossibleBody control module not driving the wake-up output
- PossiblePoor terminal contact at ECM or TCM connector
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 P2537 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. |
| 37 | The exact fault in that area. |
What to do next
- Note P2537 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 P2537
What does P2537 mean?
P2537 means "Ignition Switch Accessory Position Circuit Low". P2537 reports that the accessory or accessory wake-up input sits low where a high level is expected. It is a generic code, so it means the same on every make.
Is it safe to drive with P2537?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2537 fail an emissions test?
P2537 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 P2537 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2537 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.