P2517

A/C Refrigerant Pressure Sensor "B" Circuit Low

Severity: Low
Driving: No driving restriction

The refrigerant pressure signal from sensor "B" is reading low - typically shorted to earth or an open circuit, though a genuinely empty system reads low too.

Possible causes

CommonLow refrigerant charge, usually from a slow leak
CommonFailed refrigerant pressure sensor
CommonCorroded connector or damaged wiring
PossibleBlocked condenser restricting flow
PossibleLoss of reference voltage or earth
PossibleFailed compressor

What you might notice

Air conditioning not cooling
Compressor not engaging
Cooling fans running constantly
Air conditioning cutting in and out
Check engine light on

What to check, in order

Have the refrigerant charge checked. The pressure sensor exists to protect the compressor, and a low charge makes it do exactly what this code describes - the sensor is often right.
Inspect the connector for corrosion and water.
Check the reference voltage and earth at the sensor.
Check the condenser is clear of leaves, insects and road debris.
If refrigerant has been lost, find the leak rather than simply recharging. A system topped up without repair will be empty again within months.

Read this code from your own car

Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.

Get Pin16 on Google Play

Where this code sits

B · Body C · Chassis P · Powertrain U · Network and communication

Vehicle speed control, idle control and auxiliary inputs