OBD Guide
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P04AB

EVAP System Purge Control Valve B Circuit/Open

P04AB is an OBD-II diagnostic trouble code meaning: EVAP System Purge Control Valve B Circuit/Open. Common causes: purge valve b control circuit wire open, poor contact in valve connector. Estimated repair cost: $17–78.

Severity
✅ Low
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$17–78 (est.)

Symptoms

  • Check Engine Light Is On
  • The smell of gasoline from the engine compartment or in the cabin
  • Deteriorating fuel economy
  • Increased fuel evaporation (environmental disturbances)
  • Unstable idle when warming up
  • Difficulty starting after a long stay in the heat

Causes

  • Purge Valve B Control Circuit Wire Open
  • Poor contact in valve connector
  • Blown EVAP circuit fuse
  • Faulty purge valve solenoid (winding break)
  • Damage to wiring from environmental influences (corrosion, chafing)
  • ECU malfunction (rare)

How to Fix

  1. Check the EVAP circuit fuse according to the car diagram
  2. Measure the resistance of the purge valve solenoid B (standard: 20-50 ohms depending on the brand)
  3. Check the supply voltage at the valve connector when the ECU commands to open
  4. Inspect the connector and wiring for damage and oxidation.
  5. Check the circuit from the ECU to the valve for open circuit with a multimeter
  6. Perform valve activation test via scanner
  7. Replace the valve if the solenoid is internally broken
  8. Reset codes and perform EVAP system check

Related codes

P04ACP04ADP04AEP04AFP0440P0441P0446

Error P04AB by Vehicle Brand

AcuraAudiBAICBMWBYDBuickCadillacChanganCheryChevroletChryslerCitroenDodgeDongfengExeedFAWFordForthingFotonGACGMGMCGeelyGreat WallHavalHondaHongqiHyundaiInfinitiJACJaecooJaguarJeepJetourKaiyiKiaLadaLexusLi AutoLifanLincolnLivanMazdaMercedes-BenzMercuryMitsubishiNIONissanOldsmobileOmodaOpelPeugeotPlymouthPontiacRenaultSWMSaturnSkodaSkywellSubaruSuzukiTankToyotaVolkswagenVolvoVoyahXPengZeekrZotye

FAQ

What does the P04AB code mean?

P04AB is an OBD-II diagnostic trouble code that indicates: EVAP System Purge Control Valve B Circuit/Open

What causes a P04AB error code?

The most common causes of P04AB include: Purge Valve B Control Circuit Wire Open; Poor contact in valve connector; Blown EVAP circuit fuse; Faulty purge valve solenoid (winding break).

How do I fix a P04AB diagnostic trouble code?

To fix P04AB: Check the EVAP circuit fuse according to the car diagram. Measure the resistance of the purge valve solenoid B (standard: 20-50 ohms depending on the brand). Check the supply voltage at the valve connector when the ECU commands to open. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P04AB?

Do not drive — repair immediately

How much does it cost to fix P04AB?

The estimated repair cost for P04AB is $17–78. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat