B0170

HVAC Mode Door Position Sensor

Moderate severity

The HVAC control module reports an implausible position signal from the mode (air distribution) door feedback sensor. Without valid feedback the actuator cannot be regulated to the correct position.

Common causes

Mode door position sensor failed
One of the most commonly reported causes for this code — check this first.
high
Typical part cost: $90-660
Wiring or connector fault to actuator
A plausible cause — test and verify before replacing parts.
medium
Typical part cost: $90-660
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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.

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Related codes

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Frequently asked questions

What does B0170 mean?

B0170 means "HVAC Mode Door Position Sensor". It is a generic OBD-II code that points to a fault in the body.

What are the most common causes of B0170?

mode door position sensor failed; wiring or connector fault to actuator — 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.

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