Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2003 Lincoln Navigator RWDFACTORY OEM SERVICE PROCEDURE
In-Vehicle Temperature/Humidity Sensor
The in-vehicle temperature/humidity sensor operates in the following manner:
- A thermistor in the in-vehicle temperature/humidity sensor measures air temperature inside the passenger compartment.
- A humidity transducer in the in-vehicle temperature/humidity sensor measures in-vehicle humidity.
- A hose and elbow is connected between the plenum chamber and the in-car temperature/humidity sensor.
- Airflow through the plenum chamber creates a venturi-type suction through the hose which draws passenger compartment air through the in-vehicle temperature/humidity sensor and across the thermistor and humidity transducer.
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.