The P20B8 OBD-II code refers to an issue with the Reductant Metering Unit Heater Control Circuit, specifically indicating that the circuit is reporting a high voltage. This code is crucial for vehicles equipped with a diesel exhaust fluid (DEF) system as it relates to the heating unit that prevents DEF fluid from freezing or crystallizing.
What Does the P20B8 Code Mean?
The P20B8 code signals a problem within the reductant metering unit heater’s control circuit. This heater is essential for keeping the DEF fluid at an optimal temperature, ensuring proper function of the system that reduces emissions in diesel engines.
What Causes the P20B8 Code?
Several factors can trigger the P20B8 code, including:
- Failure of the delivery module heater
- Malfunction of the power heater module power switch
- Wiring issues within the control circuit
What Are the Symptoms of the P20B8 Code?
Symptoms associated with the P20B8 code may include:
- Inability to perform DPF (Diesel Particulate Filter) regeneration
- Check Engine Light illumination
- Possible performance issues in the vehicle
How Serious Is the P20B8 Code?
The P20B8 code is classified as urgent. Ignoring this code can lead to severe damage to the vehicle’s emissions system and potentially harm the driver and passengers due to improper exhaust treatment.
How to Diagnose the P20B8 Code
To diagnose the P20B8 code, a mechanic should:
- Use an OBD-II scanner to confirm the presence of the code
- Inspect the wiring and connectors related to the reductant metering unit for any signs of damage or corrosion
- Test the delivery module heater and the power switch for proper function
- Perform continuity tests to ensure there are no breaks in the circuit
Common Repairs for the P20B8 Code
Common repairs to address the P20B8 code may include:
- Replacing a faulty delivery module heater
- Repairing or replacing the power heater module power switch
- Fixing any wiring issues found in the circuit
How Much Does It Cost to Fix the P20B8 Code?
The cost to fix the P20B8 code can vary significantly depending on the specific repairs needed. On average, repairs can range from $150 to $600, which includes parts and labor. Diagnosing the issue may incur additional costs.
Can I Fix the P20B8 Code Myself?
While some vehicle owners may be capable of diagnosing and even repairing issues associated with the P20B8 code, it is generally recommended to consult a professional mechanic. This is especially true for electrical issues and component failures, as improper repairs can lead to further damage.
