Ignition Switch Run/Start Position Circuit
The P2535 code means the vehicle's onboard diagnostic system has detected: Ignition Switch Run/Start Position Circuit. This is a critical severity code.
- Keep driving?
- No — stop driving
- DIY difficulty
- hard
- Estimated cost
- $150 - $700 (parts and labor)
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What Are the Symptoms of P2535?
- Engine will not crank
- No response when turning key to start
- Dashboard lights come on but starter does not engage
- Push button start not functioning
What Causes P2535? (Most Likely First)
- Failed ignition switch start position contacts Very High
- Faulty starter relay driven by ignition circuit High
- Neutral safety switch preventing start signal Moderate
- ECM not receiving start/run transition signal Low
Can I Still Drive with P2535?
No — stop driving. P2535 is rated critical severity. Continuing to drive in this state risks further damage — get it looked at before your next trip.
Frequently Asked Questions
Why won't my engine crank with P2535?
The ECM is not receiving the proper signal indicating the ignition switch has moved from run to start position, so it does not command the starter relay to engage.
Is this related to the neutral safety switch?
It can be. The neutral safety switch is in the start circuit path on many vehicles. If it fails, the start signal cannot reach the ECM or starter relay.
Does P2535 affect push-button start vehicles?
Yes. Push-button vehicles still have an electronic ignition switch circuit. P2535 can set if the start button signal is not properly reaching the ECM.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose P2535?
-
Test voltage at ignition switch start terminal during cranking attempt
-
Check starter relay operation
-
Verify neutral safety switch operation in park and neutral
-
Confirm ECM receives both run and start signals
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
Which Vehicles Commonly Get P2535?
- 2008-2018 Ford F-150
- 2010-2020 Chevrolet Silverado
- 2010-2019 Toyota Tundra
- 2012-2020 Honda Pilot
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