P2537 — Ignition Switch Accessory Position Circuit Low
powertrain (engine/transmission)
Is it safe to drive?
Drive with caution Drive with caution and avoid load. Ignition faults cause misfires that quickly overheat and destroy the catalytic converter; if the Check Engine Light flashes, stop and fix it first.
How to diagnose with an OBD scanner
- Read the code and freeze frame Connect an OBD2 scanner, confirm P2537 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
- Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
- Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the ignition system for damage, corrosion, chafing or poor contact.
- Subsystem check Check for supply voltage at the ignition switch accessory position connector first; then measure resistance from the signal wire to ground — near-zero ohms confirms a short to ground in the harness.
- Subsystem check Swap the coil to another cylinder and see if the fault code follows it.
- Subsystem check Inspect spark plugs for wear, oil or carbon tracks and check plug gaps.
- Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2537 does not return.
Approximate repair cost
Repair cost depends on which component actually failed. Typical scenarios for P2537 (parts and labor, USD, independent shop rates): Replace spark plugs: $90–$250; Replace an ignition coil: $150–$380; Repair coil wiring or connector: $80–$250. Overall, fixing P2537 usually costs between $80 and $380. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.
Common questions
How do I diagnose P2537 myself?
Start with a scan: confirm P2537, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the ignition switch accessory position, and verify the suspect component against live data before buying parts.
What does OBD2 code P2537 mean?
Ignition Switch Accessory Position Circuit Low (P2537): a powertrain (engine/transmission) fault affecting the ignition system. Short, gentle driving to a shop is usually possible. Most often caused by failed ignition coil or coil pack, damaged coil wiring or connector, moisture or oil in the spark plug wells.
What are the symptoms of P2537?
Drivers most often notice: increased fuel consumption, Check Engine Light on, loss of power and jerking, hard starting, especially in damp weather.
How much does it cost to fix P2537?
Replace spark plugs — $90–$250; Replace an ignition coil — $150–$380; Repair coil wiring or connector — $80–$250. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.
What is the most common cause of P2537?
The most common causes are: failed ignition coil or coil pack, damaged coil wiring or connector, moisture or oil in the spark plug wells.
What does P2537 mean?
The engine control module sets P2537 when it detects a fault in the ignition system. In practical terms: ignition switch accessory position circuit low. The code belongs to the powertrain (engine/transmission) group of OBD2 codes.
“Circuit low” means the voltage on the ignition switch accessory position circuit stays below the expected minimum — close to ground. The usual physical reasons are a short to ground, a chafed wire touching metal, a missing supply voltage, or a failed component dragging the signal down.
The module monitors this system continuously while driving. When readings fall outside the expected range for a defined number of drive cycles, it stores P2537 and switches on the warning light. Freeze frame data saved with the code shows the exact conditions — rpm, load, temperature, speed — at the moment the fault was detected, which is the best starting point for diagnosis.
What causes P2537?
- failed ignition switch accessory position pulling the signal low
- signal wire shorted to ground (chafed insulation)
- missing supply voltage to the ignition switch accessory position
- damaged coil wiring or connector
- faulty ignition control circuit in the ECM
- moisture or oil in the spark plug wells
- failed ignition coil or coil pack
- worn spark plugs or wrong plug gap
Common symptoms of P2537
- increased fuel consumption
- Check Engine Light on
- loss of power and jerking
- hard starting, especially in damp weather
- misfires under load or at idle
How to diagnose P2537
- Connect an OBD2 scanner, confirm P2537 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
- Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
- Visually inspect the wiring harness and connectors related to the ignition system for damage, corrosion, chafing or poor contact.
- Check for supply voltage at the ignition switch accessory position connector first; then measure resistance from the signal wire to ground — near-zero ohms confirms a short to ground in the harness.
- Swap the coil to another cylinder and see if the fault code follows it.
- Inspect spark plugs for wear, oil or carbon tracks and check plug gaps.
- Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2537 does not return.
How to fix P2537
Start with the cheapest and most common causes before replacing expensive parts:
- Replace spark plugs — $90–$250
- Replace an ignition coil — $150–$380
- Repair coil wiring or connector — $80–$250
How much does it cost to fix P2537?
Repair cost depends on which component actually failed. Typical scenarios for P2537 (parts and labor, USD, independent shop rates):
- Replace spark plugs: $90–$250
- Replace an ignition coil: $150–$380
- Repair coil wiring or connector: $80–$250
Overall, fixing P2537 usually costs between $80 and $380. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.
Can you drive with P2537?
Drive with caution and avoid load. Ignition faults cause misfires that quickly overheat and destroy the catalytic converter; if the Check Engine Light flashes, stop and fix it first.