OBD-II code · Powertrain (generic, extended)
P2518 A/C Refrigerant Pressure Sensor B Circuit High
A/C refrigerant pressure sensor B signal voltage reads above the upper limit. Typically a short to reference voltage in the signal line, an open signal return, or an overpressure event briefly pegging the sensor. ECM disables variable compressor control to protect the system.
Is it safe to drive with P2518?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySignal wire shorted to reference voltage
- PossibleOpen signal return at the sensor
- Less likelyConnector pins corroded - high contact resistance
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.4–1.5 h
- Emissions test
- Usually unaffected
- Parts involved
- AC Pressure Sensor B, Sensor Wiring
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.