P20BB 2016 GMC Sierra Code - Reductant Heater 1 Control Circuit Low Voltage
Quick Answer
The P20BB diagnostic trouble code for a 2016 GMC Sierra specifically relates to the Reductant Heater 1 Control Circuit Low Voltage. Common causes include Faulty Reductant Heater: A malfunctioning reductant heater can lead to low voltage in the control circuit, Damaged Wiring or Connectors: Any damage to the wiring or connectors in the control circuit can disrupt the flow of electricity and result in low voltage, Defective Powertrain Control Module (PCM): A faulty PCM can affect the control circuit's operation and cause low voltage issues. 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
- P20BB 2016 GMC Sierra indicates Reductant Heater 1 Control Circuit Low Voltage.
- Common causes
- Common causes include Faulty Reductant Heater: A malfunctioning reductant heater can lead to low voltage in the control circuit, Damaged Wiring or Connectors: Any damage to the wiring or connectors in the control circuit can disrupt the flow of electricity and result in low voltage, Defective Powertrain Control Module (PCM): A faulty PCM can affect the control circuit's operation and cause low voltage issues.
- 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.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code P20BB 2016 GMC Sierra Description
The P20BB diagnostic trouble code for a 2016 GMC Sierra specifically relates to the Reductant Heater 1 Control Circuit Low Voltage. This code indicates that there is an issue with the electrical circuit controlling the reductant heater, which is a vital component of the selective catalytic reduction (SCR) system. The SCR system is responsible for reducing harmful emissions by converting nitrogen oxides (NOx) into nitrogen, water, and carbon dioxide.
Common Causes of P20BB 2016 GMC Sierra
- Faulty Reductant Heater: A malfunctioning reductant heater can lead to low voltage in the control circuit.
- Damaged Wiring or Connectors: Any damage to the wiring or connectors in the control circuit can disrupt the flow of electricity and result in low voltage.
- Defective Powertrain Control Module (PCM): A faulty PCM can affect the control circuit's operation and cause low voltage issues.
- Malfunctioning Temperature Sensor: If the temperature sensor responsible for monitoring the DEF temperature is not functioning correctly, it can impact the reductant heater's operation.
Symptoms of P20BB 2016 GMC Sierra
- Check Engine Light Illuminated: The most common symptom associated with the P20BB code is the illumination of the check engine light on the vehicle's dashboard.
- Reduced Fuel Efficiency: Due to the decreased efficiency of the SCR system, the vehicle may experience reduced fuel efficiency.
- Failed Emissions Test: If emissions levels are not within acceptable limits, the vehicle may fail emissions tests.
- Poor Performance: In some cases, the vehicle may exhibit poor performance or hesitation during acceleration.
How to Fix P20BB 2016 GMC Sierra
- Diagnose the Issue: Use a diagnostic scanner to retrieve the trouble codes and perform a thorough inspection of the reductant heater, wiring, connectors, and temperature sensor to identify the root cause of the problem.
- Replace Faulty Components: If a specific component such as the reductant heater, wiring, connectors, or temperature sensor is found to be defective, replace it with a new part.
- Clear Codes and Test Drive: After replacing the faulty components, clear the trouble codes from the PCM's memory and take the vehicle for a test drive to ensure that the issue has been resolved.
- Perform Emissions Test: If the vehicle previously failed emissions tests, it's essential to conduct another test after the repair to verify that emissions levels are within acceptable limits.
- Monitor Performance: Keep an eye on the vehicle's performance and check for any recurring issues related to the reductant heater or SCR system.
Cost to Fix P20BB 2016 GMC Sierra
The typical repair costs for addressing a P20BB code on a 2016 GMC Sierra can vary depending on the specific cause of the issue and the parts and labor involved. In general, replacing components such as the reductant heater, wiring, connectors, or temperature sensor can range from $200 to $800, including parts and labor. Additionally, diagnostic time and labor rates at auto repair shops can vary significantly, with hourly rates typically ranging between $80 and $150. It's advisable to check with local repair shops for a more accurate estimate based on your location and vehicle specifics.
Need more information about the P20BB 2016 GMC Sierra code?
Need more information on how to fix the P20BB 2016 GMC Sierra code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P20BB 2016 GMC Sierra code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P20BB 2016 GMC Sierra Code
1. What does the OBDII code P20BB mean for a 2016 GMC Sierra?
P20BB indicates a problem with the Reductant Heater 1 Control Circuit, specifically low voltage, which affects the functioning of the diesel exhaust fluid (DEF) system.
2. What are the symptoms of code P20BB in a 2016 GMC Sierra?
Common symptoms include a check engine light, possible reduction in DEF system efficiency, and in some cases, limited engine performance due to emissions system issues.
3. What causes the P20BB code on a GMC Sierra?
Causes may include a faulty reductant heater, damaged wiring or connectors in the control circuit, or a malfunctioning powertrain control module (PCM).
4. Is it safe to drive a 2016 GMC Sierra with code P20BB?
While the truck may still be drivable, ignoring this code could lead to reduced emissions system performance and eventually trigger limp mode, restricting power.
5. How do you diagnose the P20BB code on a 2016 GMC Sierra?
Diagnosis involves inspecting the reductant heater, checking the wiring and connectors for damage, and testing the circuit for proper voltage and continuity.
6. Can a faulty reductant heater cause code P20BB?
Yes, a defective reductant heater can lead to low voltage in the control circuit, triggering the P20BB code.
7. How is the P20BB code repaired on a 2016 GMC Sierra?
Repairs may include replacing the reductant heater, repairing or replacing damaged wiring, or reprogramming or replacing the PCM if needed.
8. What tools are needed to fix code P20BB on a GMC Sierra?
You’ll need an OBDII scanner, a multimeter to test voltage and continuity, and possibly replacement parts like a reductant heater or wiring harness.
9. Does the P20BB code affect emissions on a 2016 GMC Sierra?
Yes, this code can impact the DEF system, potentially increasing emissions and reducing compliance with environmental regulations.
10. How much does it cost to fix code P20BB on a GMC Sierra?
Repair costs vary but typically range from $200 to $600, depending on whether the reductant heater or wiring needs replacement. Labor costs may increase if extensive diagnostics are required.
Discuss the causes and fixes for P20BB 2016 GMC Sierra OBDII Code
Code P20BB 2016 GMC Sierra comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.