OBD-II code · Powertrain (generic, extended)
P2535 Ignition Switch On/Start Position Circuit High
The On/Start input reads stuck high — short to battery voltage. The ECM cannot read the crank state, modules dependent on this signal are unable to time their wake-up correctly.
Is it safe to drive with P2535?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOn/Start 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
Related codes
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.