P2516A/C Refrigerant Pressure Sensor B Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2516 flags a pressure sensor B whose reading is electrically valid but does not behave like real refrigerant pressure. In GM's hybrid OBD tables sensor B is the low-side sensor, evaluated by the hybrid processor that also runs the electric compressor. The 2019 edition looks for a stuck sensor: once the car has soaked and the compressor starts, the low-side value must shift by at least 4.0 kPa within 180 s of compressor running; if it barely moves, the test fails, type B with two trips. The 2011 edition used a sample counter of 32 fails in 40 checks at 250 ms intervals. GM also blocks its charge-loss check P0534 while P2516 is active. Out-of-range voltages are P2517 and P2518 instead. Typical result: compressor control falls back to defaults, cooling is weaker.
- What you may notice
- A/C cools poorly
- Check engine light after two drives (GM type B)
- Refrigerant charge diagnosis not completed
- Likely causes
- LikelyPressure sensor stuck at one value
- PossibleCompressor runs but hardly changes pressure (very low charge, blockage)
- RareHigh resistance in signal or ground wire
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.