P20B9 2015 GMC Sierra Code - Reductant Heater 1 Control Circuit
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
- P20B9 2015 GMC Sierra indicates Reductant Heater 1 Control Circuit.
- 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.
Code P20B9 2015 GMC Sierra Description
The Diagnostic Trouble Code (DTC) will be set when the ECM indicates the reductant tank heater control circuit is open for greater than 4 s.
What are the Possible Causes of the DTC P20B9 2015 GMC Sierra?
- 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 P20B9 2015 GMC Sierra?
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 is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P20B9 2015 GMC Sierra 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.
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Frequently Asked Questions about P20B9 2015 GMC Sierra Code
What does the OBDII code P20B9 mean on a 2015 GMC Sierra?
The P20B9 code indicates an issue with the Reductant Heater 1 Control Circuit, which is responsible for heating the diesel exhaust fluid (DEF) to prevent it from freezing in cold temperatures.
What are the common symptoms of a P20B9 code on a 2015 GMC Sierra?
Common symptoms include the check engine light turning on, reduced engine performance, a DEF system warning message, and potential difficulty meeting emissions standards.
What causes the P20B9 code to appear on a 2015 GMC Sierra?
Common causes include a faulty DEF heater, damaged wiring or connectors in the heater circuit, a malfunctioning control module, or corrosion in the electrical components.
Can I drive my 2015 GMC Sierra with a P20B9 code?
While you may still be able to drive, the vehicle could enter reduced power mode over time, and prolonged driving with this issue may lead to further emissions system damage.
How do I diagnose the P20B9 code on a 2015 GMC Sierra?
Diagnosis involves scanning for codes with a compatible OBDII scanner, visually inspecting the wiring and connectors for damage or corrosion, and testing the DEF heater circuit for proper voltage and resistance.
How is the P20B9 code fixed on a 2015 GMC Sierra?
The repair typically involves replacing the faulty DEF heater, repairing or replacing damaged wiring, cleaning corroded connectors, or updating the vehicle’s software if necessary.
What tools are needed to troubleshoot the P20B9 code?
You’ll need an OBDII scanner, a digital multimeter to test electrical circuits, and possibly a wiring diagram for the DEF system.
How much does it cost to fix the P20B9 code on a 2015 GMC Sierra?
The cost varies depending on the issue. Replacing the DEF heater can cost $200-$600, while wiring repairs may cost less if only minor fixes are needed.
Can a software issue cause the P20B9 code on a 2015 GMC Sierra?
Yes, outdated or corrupted software in the powertrain control module (PCM) can sometimes cause the P20B9 code and may require a software update from the dealership.
Is the P20B9 code related to emissions compliance?
Yes, the DEF heater is crucial for proper DEF function, which is required to reduce NOx emissions and keep the vehicle compliant with emissions regulations.
Discuss the causes and fixes for P20B9 2015 GMC Sierra OBDII Code
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