Common Symptoms
- Check Engine Light illuminated
- Poor fuel economy
- Rough idle or hesitation during acceleration
- Black smoke from exhaust under load
- Hard starting in cold weather
- Engine runs rich or lean
Most Likely Root Causes
- Contaminated or faulty Intake Air Temperature sensor
- Corroded or damaged IAT sensor connector
- Intake air leaks allowing unmetered air
- Wiring harness damage or chafing between IAT sensor and ECM
- ECM software calibration issue
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Component Location
The IAT sensor is typically integrated into the Mass Airflow sensor housing or mounted in the intake air duct between the air filter and throttle body.
Manufacturer Notes
Some vehicles integrate the IAT sensor into the MAF sensor assembly requiring replacement as a complete unit rather than individually.
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Heavy-duty trucks often throw both OBD-II and J1939 faults simultaneously. AI Diesel Tech handles both protocols in a single guided session.
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