P05F3
Exhaust Aftertreatment Power Relay Control Circuit/Open
Generic OBD-II
Common symptoms
What you'll notice
- Check and replace the faulty exhaust aftertreatment power relay
- Inspect and repair any damaged or loose wiring connections related to the exhaust aftertreatment power relay
- Clean or replace the exhaust aftertreatment sensors if necessary
- Replace the power relay
Common causes
Most likely first
- Faulty or malfunctioning exhaust aftertreatment power relay
- Open circuit or damaged wiring in the exhaust aftertreatment power relay control circuit
- Loose or corroded connections in the exhaust aftertreatment power relay control circuit
- Faulty exhaust aftertreatment system components
- ECM (Engine Control Module) or PCM (Powertrain Control Module) malfunction
How to diagnose & fix
Work through it in order
- Engine misfires or runs rough
- Reduced engine power or acceleration
- Poor fuel economy
- Check engine light illuminated
- Difficulty starting the vehicle
Read & clear P05F3 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.