Ignition Switch Accessory Position Circuit High Voltage
The P2538 code indicates that the powertrain control module (PCM) has detected a voltage signal from the ignition switch accessory position circuit that is higher than the specified range. This circuit provides power to accessories like the radio and power windows when the key is in the accessory position. A high voltage condition can be caused by a faulty ignition switch, a short to voltage in the wiring, or a problem with the PCM. This issue may prevent accessories from working correctly or cause the vehicle to not start.
01. Most Common Causes
- Faulty ignition switch
- Short to voltage in the accessory circuit wiring
- Corroded or damaged connectors
- Failed PCM (rare)
02. Symptoms You Will Notice
- Accessories (radio, windows) not working in accessory position
- Engine may not start or stall
- Check Engine Light illuminated
- Battery drain
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm the code and check for other related codes.
Step 2: Visually inspect the ignition switch and wiring for damage or corrosion.
Step 3: Test the voltage at the ignition switch accessory terminal with a multimeter; should be battery voltage when key is in accessory position.
Step 4: Check for shorts to voltage in the accessory circuit by disconnecting components and measuring resistance.
Step 5: If wiring and switch are okay, test the PCM for proper operation.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as it can cause electrical issues, battery drain, or prevent the engine from starting. Have it diagnosed promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, depending on the cause. Replacing the ignition switch can cost $100-$200 including labor.