B0166

HVAC Discharge Air Temperature Sensor

Moderate severity

The HVAC control module reports an implausible signal from the discharge (vent outlet) air temperature sensor. This sensor verifies that the actual outlet air temperature matches the commanded value.

Common causes

Discharge air temp sensor failed
One of the most commonly reported causes for this code — check this first.
high
Typical part cost: $60-330
Wiring or connector fault
A plausible cause — test and verify before replacing parts.
medium
Typical part cost: $60-330
See all causes + fix costs
Create a free Wrenchify account to unlock the rest for B0166.
Unlock causes
Free forever · No credit card

First things to check

1Confirm the code with a scan tool and check for additional related codes.
2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.

Get the full step-by-step diagnosis

Create a free Wrenchify account to unlock the rest for B0166.

Unlock diagnosis

Free forever · No credit card

Related codes

See related trouble codes

Create a free Wrenchify account to unlock the rest for B0166.

Unlock related codes

Free forever · No credit card

Frequently asked questions

What does B0166 mean?

B0166 means "HVAC Discharge Air Temperature Sensor". It is a generic OBD-II code that points to a fault in the body.

What are the most common causes of B0166?

discharge air temp sensor failed; wiring or connector fault — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.

Can I keep driving with this code?

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.

Get the full B0166 diagnosis for your vehicle

Year, make, model + step-by-step repair help — free plan included.

Diagnose B0166