P2536: Ignition Switch Accessory Position Circuit

P2536 is the general fault of the accessory input, the signal that is live when the key or start button is in the accessory position and that on many vehicles also acts as a wake-up line between body and powertrain modules. The code does not say whether the line is open, low or high, only that its state cannot be used. No manufacturer documents P2536 publicly. The best analogue is P2537, which GM evaluates in engine and transmission modules; in bulletin PIT5308 GM explains that the ECM and TCM receive a 12 V accessory wake-up from the body module on circuit 5985. A faulty accessory line can disable functions that need modules awake with the engine off, such as remote start. Low and high levels are P2537 and P2538.

Symptoms

• Remote start or key-off functions not working
• Accessories behave inconsistently in the accessory position

Most likely causes

• Fault in the accessory feed or wake-up output of the body module
• Loose or corroded terminal on the accessory line
• Worn accessory contact in the ignition switch

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the connector and wiring of the coil indicated
2. Check the condition of the spark plug
3. Swap the coil with another cylinder and see if the code changes
4. Measure the power supply and control signal using the manufacturer's wiring diagram

Good to know

• Repair difficulty: medium

What each character of P2536 means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 5: Speed and idle
• 36: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2536?

Drive as little as possible. If you feel jerking or the light flashes, stop: a misfire can damage the catalytic converter.

What causes code P2536?

The most common causes are: fault in the accessory feed or wake-up output of the body module; loose or corroded terminal on the accessory line; worn accessory contact in the ignition switch.

Related codes

• P2537Ignition Switch Accessory Position Circuit Low
• P2538Ignition Switch Accessory Position Circuit High
• P2530Ignition Switch Run Position Circuit
• P2533Ignition Switch On/Start Position Circuit

Sources

• law.cornell.edu: 13 CCR 1968.2
• static.nhtsa.gov: MC 10112146 9999
• gsi.ext.gm.com: 16OBDG02 Hybrid Diagnostics

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.