What it means
The control module monitors the humidity sensor circuit for a valid signal. It sets this code when the circuit is open or the signal path is otherwise interrupted.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The humidity sensor measures moisture in the air, and its signal can help the control module manage related functions such as climate control. This code sets when the module detects an open or interrupted humidity sensor signal path rather than a usable reading.
Common causes
Most likely first.
- Signal wire open
- Pin pushed back out of connector body
- Cracked solder joint inside the module or sensor
Symptoms
- Check-engine light on
- Automatic climate control may work less accurately
- Windshield may fog more easily
How to diagnose it
- Save freeze-frame data and check scan-tool data for a missing or invalid humidity reading and any related sensor or module codes.
- Locate the humidity sensor from vehicle service information and inspect its connector for a pin pushed back, corrosion, or a loose fit.
- Trace the signal wire for breaks, pulled terminals, or damage where the harness bends or passes through trim.
- Use the wiring diagram to check circuit continuity and connector contact between the sensor and control module.
- If the wiring and connectors are sound, test the sensor and inspect for an internal cracked solder joint only where the component can be evaluated according to service information.
Common fixes
- Reconnect the humidity sensor plug and seat any displaced terminal correctly.
- Repair an open or damaged signal wire.
- Clean or replace corroded or damaged connector terminals.
- Replace the humidity sensor or affected module only if testing confirms an internal circuit fault.
Can I keep driving?
The code usually does not prevent normal driving, but automatic climate control may respond less accurately and the windshield may fog more readily. Keep the glass clear before driving and pull over if visibility becomes impaired.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.