P2516: Air Conditioning Refrigerant Pressure Sensor B Circuit Range/Performance
What to do
Expect the air conditioning to work poorly or not at all. Ask for the system's pressures to be measured on gauges before the sensor is replaced — refrigerant leaks away slowly over years, so a low charge is a more likely explanation than a failed sensor, and the gauges tell you which it is in minutes.
What this code means
The second refrigerant pressure sensor is reporting a value the module cannot reconcile.
The most common explanation is not a sensor fault at all: the refrigerant charge is genuinely wrong. These systems lose refrigerant slowly through hoses and seals as a matter of course, so a system that has never been serviced is very likely low — and a low charge produces pressures outside the expected range while every sensor works perfectly.
That makes the first question a physical one: what are the actual pressures, measured on gauges? If they match what the sensor reports, the sensor is right and the system needs attention; if they disagree, the sensor is at fault. That check is routine air conditioning work and settles it immediately.
A sensor reporting implausibly with the system switched off and cold is the other free check — pressures should equalise and sit at a predictable figure for the ambient temperature.
Likely causes
Start here
- Low refrigerant charge · moderate
- Faulty air conditioning refrigerant pressure sensor · easy
- Refrigerant leak · moderate
Less common
- Blocked or restricted condenser · moderate
- Faulty air conditioning compressor · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about P2516.