OBD Guide

P20B2

Reductant Heater Coolant Control Valve Performance/Stuck Open

P20B2 is an OBD-II diagnostic trouble code meaning: Reductant Heater Coolant Control Valve Performance/Stuck Open. Common causes: mechanical valve jamming, open or short circuit in control circuit. Estimated repair cost: $50–133.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$50–133 (est.)

Symptoms

  • Check Engine Light Is On
  • Reduced engine power
  • Increased AdBlue urea consumption
  • Increased NOx emissions
  • SCR error message on dashboard

Causes

  • Mechanical valve jamming
  • Open or short circuit in control circuit
  • Valve solenoid malfunction
  • Problems with the SCR control unit
  • Valve contaminated or corroded

How to Fix

  1. Check the condition of the valve and its electrical connections
  2. Test the resistance of the electromagnet winding
  3. Check voltage at valve connector
  4. Clean or replace faulty valve
  5. If necessary, reflash the SCR control unit

Related codes

Error P20B2 by Vehicle Brand

FAQ

What does the P20B2 code mean?

P20B2 is an OBD-II diagnostic trouble code that indicates: Reductant Heater Coolant Control Valve Performance/Stuck Open

What causes a P20B2 error code?

The most common causes of P20B2 include: Mechanical valve jamming; Open or short circuit in control circuit; Valve solenoid malfunction; Problems with the SCR control unit.

How do I fix a P20B2 diagnostic trouble code?

To fix P20B2: Check the condition of the valve and its electrical connections. Test the resistance of the electromagnet winding. Check voltage at valve connector. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P20B2?

Yes, but get it checked soon

How much does it cost to fix P20B2?

The estimated repair cost for P20B2 is $50–133. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat