U0296
Lost Communication With AC/DC Converter Control Module A
The vehicle bus reports loss of communication with AC/DC converter (on-board charger) module A. Charging from AC sources cannot be controlled and the high-voltage battery does not refill via this path.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Common causes
Ordered by how often each turns out to be the cause.
- Bus wiring open or shortedCommon
- Module without power or groundPossible
- Module failedPossible
Parts involved
- AC Dc Converter Module A
- Vehicle Bus Wiring
U0296 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.