HVAC Temperature Sensor Circuit High Input
The HVAC system has detected an abnormal voltage level at the temperature sensor.
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What it means (plain English)
Your vehicle's heating and air conditioning system is getting a voltage reading from the temperature sensor that's too high, meaning it may be faulty or shorted.
What the computer is actually seeing
The HVAC control module sees a voltage over 4.5 volts from the temperature sensor circuit when it should be under 4.5 volts, indicating a potential issue.
What a healthy reading looks like
The voltage from the sensor should range between 0.5 volts (cold) to 4.5 volts (hot).
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 at the temperature sensor for damage or corrosion. If faulty, repair or replace as needed.
- 22. Check the voltage at the temperature sensor connector with the ignition on (engine off). It should be between 0.5 and 4.5 volts. If it's above 4.5 volts, there’s a short.
- 33. With the sensor unplugged, measure the resistance across the sensor terminals while checking for continuity. Replace the sensor if it reads outside manufacturer specifications (usually 2k-4k ohms at 20°C).
- 44. If the circuit voltage is normal and the sensor tests good, inspect the HVAC control module for faults.
Common causes
- Shorted sensor circuit
- Faulty temperature sensor
- Wiring harness damage or corrosion
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Yes, you can drive, but your HVAC functions may be compromised until the issue is resolved.
Will the code come back after a repair?
If the problem is fixed correctly, the code should not return unless there's a new issue.
Why does this code pair with other codes?
Usually because they indicate related issues like other HVAC sensors or circuits that interact with the temperature sensor.
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