P20B4 Code - Diesel Exhaust Fluid Reductant Heater Control Valve Circuit High
Quick Answer
The P20B4 code indicates a problem with the Diesel Exhaust Fluid (DEF) reductant heater control valve circuit being high. Common causes include Faulty reductant heater control valve, Wiring or connection issues in the heater circuit, Corrosion or damage to the control valve. 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
- P20B4 indicates Diesel Exhaust Fluid Reductant Heater Control Valve Circuit High.
- Common causes
- Common causes include Faulty reductant heater control valve, Wiring or connection issues in the heater circuit, Corrosion or damage to the control valve.
- 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 P20B4 Description
The P20B4 code indicates a problem with the Diesel Exhaust Fluid (DEF) reductant heater control valve circuit being high. DEF is a fluid used in diesel engines to reduce emissions by converting harmful nitrogen oxides into harmless nitrogen and water. The reductant heater control valve is responsible for regulating the flow of DEF and maintaining the proper temperature for optimal performance. When this valve circuit is reading high, it means that there is an issue with the control of the heater, which can lead to inefficient DEF usage and increased emissions.
Common Causes of P20B4
- Faulty reductant heater control valve.
- Wiring or connection issues in the heater circuit.
- Corrosion or damage to the control valve.
- Defective temperature sensor.
- Software or programming issues in the engine control module.
Symptoms of P20B4
- Check engine light is illuminated on the dashboard.
- Reduced engine power or acceleration.
- Increased DEF consumption.
- Rough idling or stalling.
- Failed emissions test.
How to Fix P20B4
- Diagnose the exact cause of the high circuit reading using a scan tool.
- Inspect the wiring and connections for any damage or corrosion.
- Test the reductant heater control valve and temperature sensor for proper function.
- Replace any faulty components identified during the diagnostic process.
- Clear the error code and reset the engine control module to verify the repair.
Cost to Fix P20B4
The cost of repairing a P20B4 code can vary depending on the specific cause of the issue and the labor rates at the auto repair shop. In general, the cost can range from $200 to $500 for parts and labor. Keep in mind that additional diagnostics or repairs may be necessary, so it's advisable to consult with a professional technician for a more accurate estimate.
Need more information about the P20B4 code?
Need more information on how to fix the P20B4 code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P20B4 code diagnosed by a professional: Find a repair shop in your area
Code P20B4 Information for Specific Makes
- P20B4 Dodge — Diesel Exhaust Fluid Reductant Heater Control Valve Circuit High
- P20B4 RAM — Diesel Exhaust Fluid Reductant Heater Control Valve Circuit High
Frequently Asked Questions about P20B4 Code
No Frequently Asked Questions about P20B4 Code found.
Discuss the causes and fixes for P20B4 OBDII Code
Code P20B4 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.