AutoCodes – GMC – P20BE GMC

P20BE GMC Code - Reductant Heater 2 Performance

Quick Answer

As reductant will freeze at temperatures below -11°C (12°F), there are 2 reductant heaters located in the reductant tank. Common causes include Faulty Reductant Heater, Reductant Heater harness is open or shorted, Reductant Heater circuit poor electrical connection. 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: P20BE GMC indicates Reductant Heater 2 Performance.
Common causes: Common causes include Faulty Reductant Heater, Reductant Heater harness is open or shorted, Reductant Heater circuit poor electrical connection.
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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 4,764

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 29, 2022

Description
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P20BE GMC Description

As reductant will freeze at temperatures below -11°C (12°F), there are 2 reductant heaters located in the reductant tank. One heats the reductant in the tank, and one heats the reductant supplied to the reductant injector supply pipe. The Engine Control Module (ECM) monitors the reductant temperature in the tank in order to determine if the reductant temperature is below its freeze point. If the ECM determines that the reductant may be frozen, it activates a "defrost strategy" energizing the reductant eater. This energizing action terminates when the temperature sensor measures a threshold value over which the heater must be deactivated.
The Diagnostic Trouble Code (DTC) will be set when the ECM indicates the reductant line heater resistance is greater or less than a calibrated value for greater than 8 s.

OBDII Code P20BE GMC - Reductant Heater 2 Performance - AutoCodes.com — P20BE GMC Code - Reductant Heater 2 Performance

What does this mean?

What are the Possible Causes of the DTC P20BE GMC?

Faulty Reductant Heater
Reductant Heater harness is open or shorted
Reductant Heater circuit poor electrical connection
Faulty Reductant Pump and Sensor Assembly
Faulty Reductant Control Module

How to Fix the DTC P20BE GMC?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

User Submitted Video

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P20BE GMC code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P20BE GMC code?

Need more information on how to fix the P20BE GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P20BE GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P20BE 2014 GMC Sierra — Reductant Heater 2 Performance
P20BE 2015 GMC Sierra — Reductant Heater 2 Performance
P20BE 2016 GMC Sierra — Reductant Heater 2 Performance
P20BE 2017 GMC Sierra — Reductant Heater 2 Performance
P20BE 2018 GMC Sierra — Reductant Heater 2 Performance

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 P20BE GMC Code

1. What does the OBDII code P20BE mean on a GMC?

P20BE indicates "Reductant Heater 2 Performance," meaning there’s an issue with the second reductant heater used to prevent diesel exhaust fluid (DEF) from freezing.

2. What are the common symptoms of the P20BE code on a GMC?

Symptoms may include a Check Engine Light, DEF system warnings, poor DEF performance, or issues with emissions control.

3. What causes the P20BE code on a GMC?

Common causes include a faulty reductant heater, damaged wiring or connectors, or a malfunctioning reductant control module.

4. Can I drive my GMC with the P20BE code?

While the vehicle may still be drivable, prolonged driving with this issue can lead to reduced emissions performance and may eventually cause DEF system failure.

5. How do I fix the P20BE code on my GMC?

Repairs typically involve replacing the faulty reductant heater, inspecting and repairing wiring or connectors, or reprogramming the reductant control module if needed.

6. How much does it cost to repair the P20BE code on a GMC?

Repair costs can range from $200 to $600 or more, depending on whether the heater or associated components need replacement.

7. How can I diagnose the P20BE code on my GMC?

Diagnosis involves using an OBDII scanner to confirm the code, inspecting the DEF tank for heater operation, and checking wiring for damage or corrosion.

8. What role does the reductant heater play in the DEF system?

The reductant heater prevents DEF from freezing in cold temperatures, ensuring proper flow and functionality of the emissions system.

9. Can a bad reductant heater damage other parts of the DEF system?

Yes, a malfunctioning heater can lead to DEF crystallization, clogging, or failure of other DEF system components over time.

10. Is the P20BE code covered under GMC’s emissions warranty?

Depending on your vehicle's age and mileage, the reductant heater may be covered under the emissions warranty. Check with your dealership for specifics.