P2D78
Battery Charger Control Module B Processor Performance
The battery charger control module B reports a processor performance fault. CPU watchdog or RAM check failed.
- 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.
- CPU watchdog repeatedly resetsCommon
- RAM check failedPossible
- Module software outdated, reflash may resolveLess likely
Parts involved
- Battery Charger Cm B
P2D78 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.