P05F1
Reductant Pump Supply Voltage Circuit Stuck On
Generic OBD-II
Common symptoms
What you'll notice
- Check and replace the reductant pump fuse if necessary
- Inspect and clean the reductant pump connectors for any loose or corroded wires
- Test the reductant pump relay and replace if faulty
- Replace the reductant pump if all other solutions fail
Common causes
Most likely first
- Faulty reductant pump
- Blown fuse in the reductant pump supply circuit
- Short circuit in the reductant pump wiring
- Malfunctioning reductant pump relay
- Wiring issue in the reductant pump supply circuit
How to diagnose & fix
Work through it in order
- Engine warning light illuminates on the dashboard
- Decreased engine performance or reduced power
- Difficulty starting the vehicle or failure to start
- Increased fuel consumption
- Presence of a strong or unusual smell from the vehicle's exhaust
Read & clear P05F1 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.