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.
Affected components
- Ac pressure sensor b
- Sensor wiring
Common causes
- High likelihood: Signal wire shorted to ground
- Medium likelihood: Missing 5 V reference at the sensor
- Low likelihood: Connector pins corroded - high contact resistance
Diagnostic notes
- The malfunction indicator lamp may illuminate
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.