BMW DTC P20B6 – Reductant Metering Unit Heater Control Circuit Performance
DTC P20B6 meaning on BMW
DTC P20B6 on a BMW refers to the Reductant Metering Unit Heater Control Circuit Performance. This diagnostic trouble code indicates that there is a malfunction in the control circuit for the heater in the reductant metering unit. The reductant metering unit is a component of the Selective Catalytic Reduction (SCR) system, which helps reduce emissions in diesel engines by injecting a urea-based solution into the exhaust stream.
BMW DTC P20B6 symptoms
Symptoms of DTC P20B6 on a BMW may include:
- Check Engine Light illuminated
- Reduced engine performance
- Possible increase in emissions
BMW DTC P20B6 causes
Common causes of DTC P20B6 on a BMW include:
- Faulty reductant metering unit heater
- Wiring or connector issues in the heater control circuit
- Defective control module
BMW DTC P20B6 seriousness
DTC P20B6 should be addressed promptly as it can lead to increased emissions and potential engine performance issues. Ignoring this code may result in the vehicle failing emissions tests and could potentially cause damage to the SCR system.
How to diagnose DTC P20B6 on BMW
To diagnose DTC P20B6 on a BMW, a mechanic would typically perform the following steps:
- Use a diagnostic scanner to retrieve the fault codes
- Inspect the reductant metering unit heater and its wiring for any visible damage
- Check the control module for proper operation
- Perform electrical tests to verify the integrity of the heater control circuit
How to fix DTC P20B6 on BMW
To fix DTC P20B6 on a BMW, the following steps may be taken:
- Replace the faulty reductant metering unit heater
- Repair any damaged wiring or connectors in the control circuit
- If the control module is defective, replace it with a new one
- Clear the fault codes and perform a test drive to ensure the issue has been resolved
How to erase DTC P20B6 on BMW
To erase DTC P20B6 on a BMW, the fault codes can be cleared using a diagnostic scanner. After the repairs have been made and the issue resolved, the mechanic can use the scanner to clear the codes from the vehicle’s memory. It is important to ensure that the underlying issue causing the fault code has been addressed before clearing the code.
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
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