P2517
A/C Refrigerant Pressure Sensor B Circuit Low
Air conditioning
Generic OBD-II
Low
What it means
P2517 means the air-conditioning refrigerant pressure sensor 'B' is sending a signal that's too low, typically from a wiring short, an open circuit, or a failed sensor. The car uses this reading to control the A/C compressor and cooling fans, so the effect is limited to weak or disabled air conditioning — the engine runs normally.
Low
Can I keep driving? Safe to drive — this affects the air-conditioning system, not the engine. The A/C may cool poorly or shut off, but the car runs normally.
Common symptoms
What you'll notice
- Check-engine light on
- Weak or intermittent air-conditioning cooling
- A/C compressor may not engage
- Cooling fans may run constantly or not at the right time
Common causes
Most likely first
- Faulty A/C refrigerant pressure sensor 'B'Likely
- Short to ground or open in the sensor's signal wiringCommon
- Corroded or loose sensor connectorCommon
- Very low or lost refrigerant chargeLess often
- Loss of the 5-volt reference or ground to the sensorLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check the A/C pressure sensor's live reading with a scan tool.
- Inspect the sensor connector and wiring for a short to ground, an open, or corrosion.
- Verify the 5-volt reference and ground at the sensor connector.
- Check the system's refrigerant charge with A/C gauges.
- Replace the pressure sensor if its signal stays low with good wiring, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2517?+
Yes. It only affects the A/C system. The compressor may not run, but the engine and the rest of the car are unaffected.
Can I just clear P2517?+
It will come back until the sensor, wiring, or refrigerant charge is corrected. Clearing alone won't restore cooling.
Related codes
Often seen with P2517
Read & clear P2517 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX