P2D42A/C Compressor Motor Voltage B Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- How the car detects it
- P2D42 is stored when voltage B at the electric A/C compressor motor stays below the lower limit of its working range, so the inverter cannot drive the motor properly and usually switches it off. Unlike a sensor circuit code, it refers to the voltage that is actually present. No manufacturer documents P2D42 on an official public source. Mazda's bulletin 07-002/26 for the CX-90 and CX-70 plug-in hybrids shows the classic cause on the voltage A side (P0D6D): an internal short blows the A/C high-voltage fuse. GM's 2011 Volt flagged a compressor input of 190 V or less as P0D6B. A loose high-voltage connector or open contactors also fit. The A/C stops cooling; plug-in hybrids may lose battery cooling too.
- What you may notice
- A/C blows warm air
- Hybrid system warning, possibly reduced battery cooling or charging power
- Likely causes
- LikelyBlown A/C high-voltage fuse, often after an internal compressor short
- PossibleLoose or corroded high-voltage connector at the compressor
- PossibleInternal fault in the compressor inverter or measurement
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.