OBD Guide

P20A4

Reductant Purge Control Valve A Stuck Open

P20A4 is an OBD-II diagnostic trouble code meaning: Reductant Purge Control Valve A Stuck Open. Common causes: mechanical valve jamming, open or short circuit in valve control circuit. Estimated repair cost: $28–89.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$28–89 (est.)

Symptoms

  • Check Engine light comes on
  • Increased AdBlue fluid consumption
  • Reduced engine power
  • SCR system malfunction message appears
  • Possible smell of urea from the exhaust system

Causes

  • Mechanical valve jamming
  • Open or short circuit in valve control circuit
  • Malfunction of the solenoid part of the valve
  • Problems with the wiring harness to the valve
  • Contamination or crystallization of urea in the valve

How to Fix

  1. Check the condition of the reducing agent purge valve
  2. Check control circuit and valve power supply
  3. Clean the valve from possible deposits
  4. Replace faulty valve if necessary
  5. Reset the error code and check the system operation

Related codes

Error P20A4 by Vehicle Brand

FAQ

What does the P20A4 code mean?

P20A4 is an OBD-II diagnostic trouble code that indicates: Reductant Purge Control Valve A Stuck Open

What causes a P20A4 error code?

The most common causes of P20A4 include: Mechanical valve jamming; Open or short circuit in valve control circuit; Malfunction of the solenoid part of the valve; Problems with the wiring harness to the valve.

How do I fix a P20A4 diagnostic trouble code?

To fix P20A4: Check the condition of the reducing agent purge valve. Check control circuit and valve power supply. Clean the valve from possible deposits. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P20A4?

Yes, but get it checked soon

How much does it cost to fix P20A4?

The estimated repair cost for P20A4 is $28–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat