BMW DTC P20B7 – Reductant Metering Unit Heater Control Circuit Low
DTC P20B7 meaning on BMW
DTC P20B7 on a BMW indicates a fault with the Reductant Metering Unit Heater Control Circuit. This fault code is specific to the heating element control circuit within the reductant metering unit, which is a component of the Selective Catalytic Reduction (SCR) system used to reduce emissions in diesel engines.
BMW DTC P20B7 symptoms
Symptoms of DTC P20B7 on a BMW may include:
- Check Engine Light illuminated
- Reduced engine performance
- Possible DEF (Diesel Exhaust Fluid) system warnings
BMW DTC P20B7 causes
Common causes of DTC P20B7 on a BMW include:
- Faulty reductant metering unit heater
- Wiring or connector issues in the heater control circuit
- Defective SCR system components
BMW DTC P20B7 seriousness
The seriousness of DTC P20B7 on a BMW lies in its impact on emissions control and engine performance. Ignoring this fault code can lead to increased emissions and potential engine damage over time.
How to diagnose DTC P20B7 on BMW
To diagnose DTC P20B7 on a BMW, you can perform the following steps:
- Use a diagnostic scanner to retrieve the fault code and related data
- Inspect the reductant metering unit heater and its wiring for any visible damage
- Check the heater control circuit for continuity and proper voltage
- Test the SCR system components for proper operation
How to fix DTC P20B7 on BMW
To fix DTC P20B7 on a BMW, you may need to:
- Replace the faulty reductant metering unit heater
- Repair any damaged wiring or connectors in the heater control circuit
- Address any issues with the SCR system components
How to erase DTC P20B7 on BMW
To erase DTC P20B7 on a BMW, you can:
- Use a diagnostic scanner to clear the fault code
- Ensure that the underlying issue causing the fault code has been resolved
- Perform a test drive to confirm that the fault code does not return
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.