P2537Ignition Switch Accessory Position Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- How the car detects it
- 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.
- What you may notice
- Remote start inoperative
- Power liftgate works only with ignition on
- Blower may keep running after engine shutdown (diesel)
- Likely causes
- 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
- Repair
- Medium · Usually a job for a workshop.Typical cost: €20 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.