BMW DTC P0B21 – Hybrid/EV Battery Pack Voltage Sense ‘D’ Circuit High
DTC P0B21 meaning on BMW
DTC P0B21 on a BMW indicates an issue with the Hybrid/EV Battery Pack Voltage Sense ‘D’ Circuit being too high. This fault code is specific to the hybrid or electric vehicle system of the BMW.
BMW DTC P0B21 symptoms
Symptoms of DTC P0B21 on a BMW may include:
- Check Engine Light (MIL) illuminated
- Hybrid/EV system warning light on
- Reduced hybrid or electric vehicle performance
- Possible drivability issues
BMW DTC P0B21 causes
Common causes of DTC P0B21 on a BMW include:
- Faulty hybrid/EV battery pack voltage sensor
- Wiring or connection issues in the voltage sense circuit
- Hybrid/EV battery pack issues
- Software or control module issues
BMW DTC P0B21 seriousness
The seriousness of DTC P0B21 on a BMW depends on the underlying cause. Ignoring this fault code can lead to further damage to the hybrid or electric vehicle system, potentially resulting in drivability issues or complete system failure.
How to diagnose DTC P0B21 on BMW
To diagnose DTC P0B21 on a BMW, a mechanic would typically perform the following steps:
- Use a diagnostic scanner to retrieve the fault code and related data
- Inspect the hybrid/EV battery pack voltage sensor and its wiring for any visible damage
- Check the hybrid/EV battery pack voltage levels and overall health
- Perform system tests to identify any control module or software issues
How to fix DTC P0B21 on BMW
Fixing DTC P0B21 on a BMW may involve the following steps:
- Replace the faulty hybrid/EV battery pack voltage sensor
- Repair or replace any damaged wiring or connections in the voltage sense circuit
- Address any issues with the hybrid/EV battery pack itself
- Update software or reprogram control modules as needed
How to erase DTC P0B21 on BMW
To erase DTC P0B21 on a BMW, the fault code can be cleared using a diagnostic scanner or by disconnecting the vehicle’s battery for a few minutes. However, it is important to address the underlying cause of the fault code before clearing it to prevent it from reoccurring.
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.