B0408
Main Temperature Control Circuit
B0408 is an OBD-II diagnostic trouble code meaning: Main Temperature Control Circuit. Common causes: open or short circuit in temperature control circuit, temperature sensor malfunction. Estimated repair cost: $56–167.
Symptoms
- Incorrect operation of the climate system
- Lack of response to temperature changes
- Unstable temperature in the cabin
Causes
- Open or short circuit in temperature control circuit
- Temperature sensor malfunction
- Problems with the climate control unit
- Wiring harness damage
How to Fix
- Check the integrity of the wiring harness in the temperature control circuit
- Test the temperature sensor to specifications
- Check the operation of the climate control unit
- Replace faulty components
Related codes
Error B0408 by Vehicle Brand
FAQ
What does the B0408 code mean?
B0408 is an OBD-II diagnostic trouble code that indicates: Main Temperature Control Circuit
What causes a B0408 error code?
The most common causes of B0408 include: Open or short circuit in temperature control circuit; Temperature sensor malfunction; Problems with the climate control unit; Wiring harness damage.
How do I fix a B0408 diagnostic trouble code?
To fix B0408: Check the integrity of the wiring harness in the temperature control circuit. Test the temperature sensor to specifications. Check the operation of the climate control unit. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with B0408?
Limited driving only, diagnose soon
How much does it cost to fix B0408?
The estimated repair cost for B0408 is $56–167. Actual cost depends on your vehicle, location, and labor rates.
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