Air Conditioning (A/C) System Refrigerant Temperature Sensor Fault
Indicates an issue with the A/C refrigerant temperature sensor.
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What it means (plain English)
The A/C system has a temperature sensor that monitors the refrigerant’s temperature. If this sensor fails or is disconnected, the system can't tell if it's too hot or too cold, causing improper cooling or heating.
What the computer is actually seeing
The computer is expecting a voltage signal from the refrigerant temperature sensor that correlates with refrigerant temperature; when the sensor is faulty, the voltage stays at a fixed level (typically between 0.5V and 4.5V depending on temperature) or drops out altogether.
What a healthy reading looks like
Expected sensor voltage should vary from 0.5V to 4.5V as the temperature of the refrigerant changes from -20°C to 55°C.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Inspect the wiring and connectors leading to the refrigerant temperature sensor. Check for corrosion or damage.
- 22. Use a multimeter to measure voltage at the sensor connector with the A/C system running. Expected values should be between 0.5V and 4.5V.
- 33. If the voltage is outside the expected range, replace the refrigerant temperature sensor.
- 44. If voltage is within range, check for other A/C system codes or perform a system operation check to confirm proper cooling performance.
Common causes
- Faulty refrigerant temperature sensor
- Wiring issues (frayed or broken wires)
- Corroded connectors
- Refrigerant leaks
- Faulty A/C control module
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Yes, it's drivable but A/C performance will be affected. It’s advisable to fix it soon.
Will this code come back after clearing it?
If the underlying issue isn't fixed, the code will likely return after the A/C system is used.
Why does this code show up with other A/C codes?
A/C system faults often intertwine, particularly when multiple sensors or components are involved.
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