Climate Control Temperature Sensor Circuit Range/Performance Problem
The climate control system has detected a temperature sensor issue.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The temperature sensor in the climate control system is reading a value that is outside its normal range, indicating a potential malfunction.
What the computer is actually seeing
The climate control module expects the temperature sensor to provide a voltage signal correlating to a temperature reading. Normally, this signal should vary between 0.5 to 4.5 volts, depending on the temperature range. A reading outside of this range leads to the B1255 code.
What a healthy reading looks like
0.5 to 4.5 volts from the temperature sensor, equating to temperatures from approximately 32°F to 150°F.
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.
- 1Check for any obvious wiring issues or damaged connectors related to the temperature sensor. If found, repair before further testing and retest.
- 2Use a multimeter to check the voltage at the temperature sensor connector. You should see a voltage between 0.5 and 4.5 volts. If it’s out of range, proceed to check the sensor itself.
- 3If the voltage reading is correct, verify the sensor ground and signal return path. Check for any opens or shorts in the wiring to ensure proper connectivity.
- 4If the sensor ground and signal path are good, replace the temperature sensor and clear the code. Retest operation to ensure the problem is resolved.
Common causes
- Faulty temperature sensor
- Wiring issues in the sensor circuit
- Poor connections at the sensor or climate control module
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Yes, but you may experience climate control issues until it's fixed.
Will this code come back after clearing it?
If the underlying issue isn't resolved, the code will likely return.
Why does this relate to the climate control system?
The climate system relies on accurate temperature readings to adjust heating and cooling. An incorrect sensor value can affect comfort.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →