OBD-II Generic Error Code P2517: How to Fix It

Q: Can I drive my car with a P2517 code?

Yes, in most cases your vehicle will still drive normally with a P2517 code active. However, your A/C system may not work properly or may shut itself off to protect the compressor. You should address the code promptly, because running the A/C compressor with low refrigerant can cause it to overheat and fail — and compressor replacement is significantly more expensive than fixing the sensor or a small leak.

Q: What is the difference between the A/C pressure sensor A and B circuits?

On vehicles equipped with dual pressure sensors, sensor A typically refers to the low-pressure side of the A/C system while sensor B refers to the high-pressure side, or vice versa depending on the manufacturer. P2517 specifically refers to the B sensor circuit reading low. Always consult your vehicle's specific wiring diagram to identify which physical sensor corresponds to the B designation on your make and model.

Q: How much does it cost to fix code P2517?

Costs vary depending on the root cause. Replacing the A/C refrigerant pressure sensor itself typically costs $30–$100 for the part, plus $50–$150 in labor. If the system needs refrigerant recovered, a leak repaired, and then recharged, total costs can range from $150 to $400 or more. Wiring repairs are usually $75–$200 depending on complexity. Getting a diagnosis from a shop first — usually $75–$150 — helps pinpoint the exact cause before spending money on parts.

Q: Will a low refrigerant charge cause the P2517 code?

Yes, absolutely. If the refrigerant level drops due to a leak, the actual system pressure will be lower than normal, and the A/C pressure sensor B will report a low-voltage signal to the PCM — triggering P2517. In this case, simply replacing the sensor will not fix the code. The underlying refrigerant leak must be found and repaired, and the system must be recharged to the correct specification before the code will clear permanently.

Q: Can a bad PCM cause code P2517?

It is possible but uncommon. A faulty PCM that is not supplying the correct 5-volt reference voltage to the sensor circuit can cause P2517 to set. Before suspecting the PCM, thoroughly check all wiring connections and the sensor itself — PCM failures are relatively rare and expensive to diagnose. If all wiring and the sensor test correctly but the reference voltage is absent or incorrect, have the PCM checked by a professional using factory-level scan tools before replacing it.

Abstract

The P2517 diagnostic trouble code means your vehicle's onboard computer has detected an abnormally low signal from the A/C refrigerant pressure sensor B circuit. This sensor monitors the pressure of the refrigerant in your air conditioning system, and a low reading typically points to a faulty sensor, a wiring problem, or an actual drop in refrigerant pressure. While your vehicle will usually still drive normally, ignoring this code can lead to A/C compressor damage or a complete loss of cabin cooling.