P20B8
Reductant Metering Unit Heater Control Circuit High
P20B8 is an OBD-II diagnostic trouble code meaning: Reductant Metering Unit Heater Control Circuit High. Common causes: open or short circuit in the heater circuit, malfunction of the heating element of the dosing unit. Estimated repair cost: $56–278.
Symptoms
- Check Engine Light Is On
- Reduced engine power
- Increased fuel consumption
- SCR System Error Message
- Problems starting in cold weather
Causes
- Open or short circuit in the heater circuit
- Malfunction of the heating element of the dosing unit
- Problems with the relay or circuit fuse
- Engine control unit malfunction
- Corrosion or poor contact in connectors
How to Fix
- Check heater circuit fuses and relays
- Check the integrity of wiring and connectors
- Measure the resistance of the heating element
- Check control signals from the computer
- If necessary, replace the dosing unit or its heater
Related codes
Error P20B8 by Vehicle Brand
FAQ
What does the P20B8 code mean?
P20B8 is an OBD-II diagnostic trouble code that indicates: Reductant Metering Unit Heater Control Circuit High
What causes a P20B8 error code?
The most common causes of P20B8 include: Open or short circuit in the heater circuit; Malfunction of the heating element of the dosing unit; Problems with the relay or circuit fuse; Engine control unit malfunction.
How do I fix a P20B8 diagnostic trouble code?
To fix P20B8: Check heater circuit fuses and relays. Check the integrity of wiring and connectors. Measure the resistance of the heating element. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P20B8?
Yes, but get it checked soon
How much does it cost to fix P20B8?
The estimated repair cost for P20B8 is $56–278. Actual cost depends on your vehicle, location, and labor rates.
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