• Accessories not working when key is in accessory position
• Check Engine Light illuminated
• Intermittent power to accessories
• Faulty ignition switch
• Short circuit in the wiring
• Faulty PCM
PCM: Powertrain Control Module
OBD-II: On-Board Diagnostics, Second Generation
• P2539
• P2540
Ignition Switch Accessory Position Circuit High
This code means that the car's computer has detected a problem with the part of the ignition switch that controls things like the radio and lights when the key is turned to the accessory position.
The P2538 code is triggered when the Powertrain Control Module (PCM) detects a voltage signal from the ignition switch accessory circuit that is higher than expected.
The ignition switch accessory position circuit is responsible for sending a signal to the car's computer to activate accessories like the radio, interior lights, and power windows when the ignition key is turned to the accessory position. A 'high' signal indicates that the voltage is above the expected range, possibly due to a short circuit or a faulty ignition switch.
• Check for any blown fuses related to the ignition circuit.
• Inspect the ignition switch for damage or wear.
• Test the wiring for shorts or open circuits.
• Replace the faulty ignition switch.
• Repair or replace damaged wiring.
• Reprogram or replace the PCM if necessary.
• Multimeter
• Screwdriver set
• OBD-II scanner
$100 - $400
Moderate
• Chevrolet Silverado
• Ford F-150
• Toyota Camry
• Regularly inspect the ignition switch for signs of wear.
• Ensure wiring is properly insulated and secured.
• Avoid overloading the accessory circuits with aftermarket devices.
Electrical Circuit Issue
• Avoid using accessories until the issue is resolved.
• Consult a professional mechanic for accurate diagnosis.
Repairs may be covered under the vehicle's electrical system warranty if the vehicle is still under warranty.
This code is commonly associated with older vehicles where the ignition switch has experienced wear and tear.
Moderate – While the vehicle may still be drivable, the accessory functions will be impaired, and the issue should be addressed to prevent further electrical problems.
Driving with a faulty ignition switch can lead to unexpected accessory failures, which may affect driving comfort and safety.
• Vehicle in accessory mode
• Monitoring voltage levels with a multimeter
The ignition switch is typically located on the steering column, near the steering wheel.
Q: Can I drive my car with a P2538 code?
A: Yes, but you may experience issues with accessory functions like the radio and lights.
Q: How do I know if my ignition switch is bad?
A: If accessories don't work when the key is in the accessory position, or if the Check Engine Light is on, the ignition switch may be faulty.
