P2516
A/C Refrigerant Pressure Sensor B Circuit Range/Performance
A/C refrigerant pressure sensor B is electrically intact, but its reading does not match the system model — for example pressures that do not fall when the compressor is off, do not change with ambient temperature, or contradict pressure sensor A. Often a refrigerant charge issue or a contaminated sensor.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Low refrigerant chargeCommon
- Contaminated or aged sensor diaphragmPossible
- Sensor element aged beyond calibration windowLess likely
Parts involved
- AC Pressure Sensor B
- Refrigerant Charge
P2516 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.