Engine-Codes.com
Engine-Codes – Generic – P20B9

P20B9 Code - Reductant Heater 1 Control Circuit

Quick Answer

The P20B9 code refers to a fault in the Reductant Heater 1 Control Circuit. Common causes include Faulty reductant heater, Wiring issues or shorts in the control circuit, Defective temperature sensor. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P20B9 indicates Reductant Heater 1 Control Circuit.
Common causes
Common causes include Faulty reductant heater, Wiring issues or shorts in the control circuit, Defective temperature sensor.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
What is this?
Table of contents Created and updated by William Orellana on Aug 19, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P20B9 Description

The P20B9 code refers to a fault in the Reductant Heater 1 Control Circuit. The reductant heater is a component of the Selective Catalytic Reduction (SCR) system, which is responsible for reducing harmful emissions in diesel vehicles. The reductant heater warms up the diesel exhaust fluid (DEF) to help it react with harmful nitrogen oxides (NOx) in the exhaust stream, converting them into harmless nitrogen and water vapor.

OBDII Code P20B9 - Reductant Heater 1 Control Circuit
P20B9 Code - Reductant Heater 1 Control Circuit

Common Causes of P20B9

  1. Faulty reductant heater
  2. Wiring issues or shorts in the control circuit
  3. Defective temperature sensor
  4. Corrosion or damage to electrical connections
  5. ECM (Engine Control Module) software issues

Symptoms of P20B9

  1. Check Engine Light illuminated
  2. Reduced fuel efficiency
  3. Increased emissions
  4. Reduced engine performance
  5. Failure to pass emissions tests

How to Fix P20B9

  1. Diagnose the code using a diagnostic scanner to pinpoint the exact cause of the issue
  2. Inspect the reductant heater and associated wiring for any visible damage or corrosion
  3. Test the temperature sensor for proper functionality
  4. Repair or replace any damaged wiring or electrical connections
  5. Clear the code, reset the ECM, and perform a test drive to ensure the issue has been resolved

Cost to Fix P20B9

The cost of repairing a P20B9 code can vary depending on the specific cause of the issue and the labor rates in your area. On average, the parts for this repair could range from $100 to $300, while labor costs could range from $100 to $300 as well. It's important to note that these are rough estimates and actual costs may vary. Be sure to consult with a qualified mechanic or repair shop for a more accurate quote.

What does this mean?

Tech Notes for P20B9













User Submitted Video

Need more information about the P20B9 code?

Need more information on how to fix the P20B9 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P20B9 code diagnosed by a professional: Find a repair shop in your area

Code P20B9 Information for Specific Makes

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P20B9 Code

No Frequently Asked Questions about P20B9 Code found.

Discuss the causes and fixes for P20B9 OBDII Code

Submit a New Comment

Code P20B9 comments

No comments found for this page.