P2517
A/C Refrigerant Pressure Sensor B Circuit Low
A/C refrigerant pressure sensor B signal voltage reads below the lower limit. Either a short to ground in the signal wire, an open reference voltage at the sensor, or an internal short. The ECM ignores the reading and disables A/C closed-loop control until the circuit recovers.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Signal wire shorted to groundCommon
- Missing 5 V reference at the sensorPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- AC Pressure Sensor B
- Sensor Wiring
P2517 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.