P2D77
Battery Charger Control Module B Performance
The battery charger control module B reports a performance fault. Internal self-tests fail or response time outside calibration.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Symptoms
- Charge status indicator shows fault
- Charging may not start or interrupts
- Slower-than-expected charge rate
Common causes
Ordered by how often each turns out to be the cause.
- Internal module faultCommon
- Communication with BMS degradedPossible
Parts involved
- Battery Charger Cm B
- Bms
P2D77 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.