OBD Guide
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P05F1

Reductant Pump Supply Voltage Circuit Stuck On

P05F1 is an OBD-II diagnostic trouble code meaning: Reductant Pump Supply Voltage Circuit Stuck On. Common causes: welded adblue pump relay contacts, malfunction of the control transistor in the adblue control unit. Estimated repair cost: $11–111.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$11–111 (est.)

Symptoms

  • AdBlue pump runs when ignition is off
  • Fast consumption of AdBlue reagent
  • Check Engine Light and AdBlue Warning Light On
  • Possible pump overheating
  • Battery discharge when parked for a long time

Causes

  • Welded AdBlue pump relay contacts
  • Malfunction of the control transistor in the AdBlue control unit
  • Relay control circuit short circuit
  • AdBlue ECU malfunction

How to Fix

  1. Check if the AdBlue pump works with the ignition off (by hand or by ear)
  2. Find and remove the AdBlue pump power relay - if the pump stalls, the relay is welded
  3. Measure the relay contacts with a multimeter with the relay removed
  4. Replace the AdBlue pump power relay
  5. If after replacing the relay the error repeats, check the relay control circuit
  6. Diagnose the AdBlue system control unit

Related codes

P05F2P05F0P05EEP20E8P204F

Error P05F1 by Vehicle Brand

AcuraAudiBAICBMWBYDBuickCadillacChanganCheryChevroletChryslerCitroenDodgeDongfengExeedFAWFordForthingFotonGACGMGMCGeelyGreat WallHavalHondaHongqiHyundaiInfinitiJACJaecooJaguarJeepJetourKaiyiKiaLadaLexusLi AutoLifanLincolnLivanMazdaMercedes-BenzMercuryMitsubishiNIONissanOldsmobileOmodaOpelPeugeotPlymouthPontiacRenaultSWMSaturnSkodaSkywellSubaruSuzukiTankToyotaVolkswagenVolvoVoyahXPengZeekrZotye

FAQ

What does the P05F1 code mean?

P05F1 is an OBD-II diagnostic trouble code that indicates: Reductant Pump Supply Voltage Circuit Stuck On

What causes a P05F1 error code?

The most common causes of P05F1 include: Welded AdBlue pump relay contacts; Malfunction of the control transistor in the AdBlue control unit; Relay control circuit short circuit; AdBlue ECU malfunction.

How do I fix a P05F1 diagnostic trouble code?

To fix P05F1: Check if the AdBlue pump works with the ignition off (by hand or by ear). Find and remove the AdBlue pump power relay - if the pump stalls, the relay is welded. Measure the relay contacts with a multimeter with the relay removed. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P05F1?

Yes, but get it checked soon

How much does it cost to fix P05F1?

The estimated repair cost for P05F1 is $11–111. Actual cost depends on your vehicle, location, and labor rates.

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