P05F1: Reductant Pump Supply Voltage Circuit Stuck On
Methodology: We combine code standards with complaint and reliability patterns, then review for clear, vehicle-first diagnosis steps.
Sources: SAE/OBD-II definitions, manufacturer service information, and public reliability reports (including NHTSA where applicable).
Limits: Guidance is informational and may not match every model-year or revision. Confirm with the official manual and diagnostics before replacing parts. For safety-critical or electrical work, use a qualified technician.
What Does P05F1 Mean?
P05F1 is a diagnostic trouble code indicating: Reductant Pump Supply Voltage Circuit Stuck On. This code relates to the vehicle speed and idle control system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.
Symptoms of P05F1
- β οΈ Check Engine Light (MIL) illuminated
- β οΈ Reductant Pump Supply Voltage remains active when it should be off
- β οΈ Related system running continuously
- β οΈ Erratic idle speed
Common Causes
- π Reductant Pump Supply Voltage mechanically stuck in active position
- π Short circuit holding Reductant Pump Supply Voltage control on
- π Faulty Reductant Pump Supply Voltage driver circuit in ECM/PCM
Frequently Asked Questions
What does P05F1 mean?
Can I drive with code P05F1?
How much does it cost to fix P05F1?
What To Do Next
Possible Fixes
- π§ Inspect Reductant Pump Supply Voltage for mechanical binding or debris
- π§ Replace stuck Reductant Pump Supply Voltage
- π§ Check Reductant Pump Supply Voltage control circuit for short
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1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
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2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
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Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50β$150) pinpoints the root cause.