OBD Guide

P20B9

Reductant Heater A Control Circuit/Open

P20B9 is an OBD-II diagnostic trouble code meaning: Reductant Heater A Control Circuit/Open. Common causes: broken wire in the heater circuit, heating element malfunction. Estimated repair cost: $17–89.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–89 (est.)

Symptoms

  • Check Engine Light Is On
  • Reduced engine power
  • Increased fuel consumption
  • SCR System Error Message
  • Emission control system malfunction

Causes

  • Broken wire in the heater circuit
  • Heating element malfunction
  • Heater control relay problems
  • Short circuit in the circuit
  • SCR control module malfunction

How to Fix

  1. Check the integrity of wires and connections
  2. Check the resistance of the heating element
  3. Check the operation of the control relay
  4. Check heater circuit fuses
  5. Diagnostics of the SCR control module

Related codes

Error P20B9 by Vehicle Brand

FAQ

What does the P20B9 code mean?

P20B9 is an OBD-II diagnostic trouble code that indicates: Reductant Heater A Control Circuit/Open

What causes a P20B9 error code?

The most common causes of P20B9 include: Broken wire in the heater circuit; Heating element malfunction; Heater control relay problems; Short circuit in the circuit.

How do I fix a P20B9 diagnostic trouble code?

To fix P20B9: Check the integrity of wires and connections. Check the resistance of the heating element. Check the operation of the control relay. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P20B9?

Yes, but get it checked soon

How much does it cost to fix P20B9?

The estimated repair cost for P20B9 is $17–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat