Refrigerant Pressure Sensor Error
Indicates a fault in the refrigerant pressure sensor circuit.
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What it means (plain English)
The computer can't correctly read the pressure of the refrigerant in the AC system, which can lead to cooling issues or system damage.
What the computer is actually seeing
The refrigerant pressure sensor is sending a signal that doesn't match expected pressure values, typically indicated by voltage levels outside of the normal range (0.5V to 4.5V).
What a healthy reading looks like
Expected refrigerant pressure in the system should range from 25-45 psi when the system is running in cool mode at ambient temperatures.
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 for damage or corrosion; repair any that are faulty. If wiring looks good, move to the next step.
- 22. Check refrigerant level with a gauge. If low, recharge the system and retest. If level is normal, proceed to step 3.
- 33. Test the refrigerant pressure sensor; unplug and measure the voltage with a multimeter while the system is running. It should read between 0.5V and 4.5V. If not, replace the sensor. If reading is good, continue to step 4.
- 44. Check for any faults stored in the ECU related to the AC system or refrigerant pressure and address those if present.
Common causes
- Faulty refrigerant pressure sensor
- Wiring or connector issues
- Low refrigerant level
- AC system contamination
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
Yes, but the AC may not work properly, and continued use can damage the AC system.
Will the code come back after repairs?
As long as the underlying issue is fixed, it shouldn't return.
Why does this code pair with SPN 1978?
SPN 1978 is related to refrigerant temperature; both issues pertain to the AC system's performance.
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