BMW DTC P202B – Reductant Tank Heater Control Circuit Low
DTC P202B meaning on BMW
DTC P202B on a BMW indicates a fault with the Reductant Tank Heater Control Circuit being detected as low. The reductant tank heater is responsible for maintaining the temperature of the diesel exhaust fluid (DEF) to prevent freezing in cold temperatures. This fault code suggests that there is an issue with the control circuit that manages the reductant tank heater.
BMW DTC P202B symptoms
Symptoms of DTC P202B on a BMW may include:
- Check Engine Light illuminated
- Reduced engine performance
- Possible DEF freezing in cold weather
BMW DTC P202B causes
Common causes of DTC P202B on a BMW include:
- Faulty reductant tank heater
- Wiring issues in the heater control circuit
- Defective temperature sensor
BMW DTC P202B seriousness
The seriousness of DTC P202B on a BMW lies in the potential for DEF freezing in cold weather conditions, which can lead to emission control system malfunctions and reduced engine performance. It is important to address this issue promptly to ensure proper operation of the vehicle.
How to diagnose DTC P202B on BMW
To diagnose DTC P202B on a BMW, you can perform the following steps:
- Use a diagnostic scanner to retrieve the fault code and freeze frame data
- Inspect the reductant tank heater and its wiring for any visible damage
- Check the temperature sensor for proper operation
- Perform a continuity test on the heater control circuit
How to fix DTC P202B on BMW
To fix DTC P202B on a BMW, you can try the following solutions:
- Replace the faulty reductant tank heater
- Repair any damaged wiring in the heater control circuit
- Replace the defective temperature sensor
- Clear the fault code and reset the Check Engine Light
How to erase DTC P202B on BMW
To erase DTC P202B on a BMW, you can use a diagnostic scanner to clear the fault code from the vehicle’s memory. Once the issue has been addressed and fixed, you can reset the Check Engine Light by erasing the fault 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
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.