P031D
Ignition D Control Signal Circuit/Open
Generic OBD-II
Common symptoms
What you'll notice
- Check the ignition coil for any loose connections or damaged wiring.
- Inspect the ignition control module for any faults or malfunctions.
- Test the ignition switch to ensure it is functioning properly.
- Verify the condition of the spark plugs and replace if necessary.
- Perform a diagnostic scan to identify any other potential issues with the ignition system.
Common causes
Most likely first
- Malfunctioning ignition coil
- Faulty ignition control module
- Broken or loose wiring connections in the ignition system
- Defective ignition switch
- Issues with the Engine Control Unit (ECU) communication with the ignition system
How to diagnose & fix
Work through it in order
- Engine misfires or runs rough
- Difficulty starting the vehicle
- Decreased engine performance
- Check engine light is illuminated
- Poor fuel economy
Read & clear P031D yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.