Intake Air Temperature Sensor 1 Circuit Range/Performance
What it means
The engine computer compares the intake air temperature (IAT) reading with other temperature sensors, such as the coolant temperature sensor after a long cold soak, or watches how it changes while driving. If the reading is illogical or stuck, it sets this code even though the electrical circuit may be intact.
Symptoms4
- Check engine light on.
- Slightly higher fuel consumption.
- Occasional mildly hard starting.
- Often no noticeable symptom besides the light.
Possible causes5
- Slow-responding IAT sensor or one whose resistance has drifted with age.
- Sensor coated with oil or dust.
- Extra resistance in the connector or wiring from corrosion.
- Sensor mounted where engine heat affects it, such as in a non-original air duct.
- Fault in the sensor it is compared with, such as the coolant temperature sensor.
How to diagnose5
- After the car has sat for several hours, compare the IAT reading with coolant temperature and outside air; they should be close.
- Watch the reading while driving; it should move toward outside air temperature as speed rises.
- Inspect the connector for corrosion that adds resistance.
- Measure sensor resistance at several temperatures and compare with the manufacturer table.
- Confirm the air duct is original and the sensor is in its correct place.
How to fix5
- Clean or replace the connector pins.
- Clean the sensor if it is contaminated.
- Return the sensor or air duct to the original setup.
- Replace the IAT sensor, or the MAF sensor if it is built in.
- Clear the codes and confirm the readings agree after a long cold soak.
Repair cost
In Saudi riyals; the highlighted part is the expected range for this fault.
The cost is low for a connector cleaning or a separate sensor, and rises when the sensor is built into the MAF sensor.
Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026
Frequently asked questions
Why does the computer compare air and engine temperature?
Because after a long rest all sensors settle near outside air temperature, so if one reads very differently the computer knows it is inaccurate.
Can extreme summer heat cause this code?
Heat alone usually does not, but an air duct routed near the engine or a weak sensor can make the reading illogical in hot weather.
This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.
Report a mistake
Spotted something inaccurate? Tell us and we will review and correct it.
Report received — thank you
This is your private tracking link. It shows the status and our reply as soon as it is posted.
The link is saved in this browser only.