What Does P2535 Mean?
The PCM has detected an abnormally high voltage signal in the ignition switch RUN/START position circuit. This indicates the voltage is above the normal operating range, typically caused by a short to power or internal switch fault.
Common Causes
35%
Short to voltage in RUN/START position wiring between switch and PCM
30%
Ignition switch internal fault causing incorrect voltage output
20%
Damaged or pinched wiring harness shorting to power source
10%
Corroded connector causing cross-circuit contamination
5%
PCM internal input circuit failure
Diagnostic Steps
1
Step 1: Disconnect ignition switch connector and check for voltage on PCM-side of RUN/START circuit (should be 0V)
2
Step 2: Inspect wiring harness routing for damage, chafing, or areas where wire may contact power sources
3
Step 3: Test for short to voltage by measuring resistance between RUN/START circuit and B+ with ignition off
4
Step 4: Verify ignition switch output voltages in each key position match manufacturer specifications
5
Step 5: Check for aftermarket installations or modifications that may have compromised ignition switch wiring
Estimated Repair Cost
$100 - $750
Parts + labor, varies by vehicle and location
The PCM has detected an abnormally high voltage signal in the ignition switch RUN/START position circuit. This indicates the voltage is above the normal operating range, typically caused by a short to power or internal switch fault.
The most common cause of P2535 (Ignition Switch Run/Start Position Circuit High) is: Short to voltage in RUN/START position wiring between switch and PCM
Typical repair costs for P2535 range from $100 to $750, depending on the vehicle, location, and whether you do it yourself or go to a shop.
May cause starting problems or unexpected electrical system behavior. Vehicle may experience difficulty starting or intermittent stalling, creating potential safety hazards.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2535 to identify the root cause.
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Quick Info
Category
Powertrain
System
Ignition System / Starting System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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