P2D42
A/C Compressor Motor Voltage B Low
The voltage B feedback of the electric A/C compressor motor is below the expected window. Phase wire shorted to ground or driver fault.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- Phase B wire shorted to groundCommon
- Output driver low-side faultPossible
Parts involved
- AC Compressor Motor
- Wiring Harness
- ECM
P2D42 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.