P0112

Intake Air Temperature Sensor 1 Circuit Low

Car Fault Codes Fuel & air

Severity Low It can wait a little, but get it checked soon.
Can you still drive? Yes, normally
Who can fix it? DIY with some experience
Typical repair time 15 minutes – 1.5 hours
Typical cost SAR 60 to 1,200

What it means

The engine computer has seen an intake air temperature (IAT) signal voltage below the lowest acceptable level. For this type of sensor, low voltage means high temperature, so the computer sees illogically hot air; the cause is usually the signal wire shorted to ground or an internal short in the sensor.

Symptoms4

  • Check engine light on.
  • Very high air temperature reading on the scan tool that does not match the weather.
  • Slight loss of performance or higher fuel consumption.
  • Occasional hard cold starting.

Possible causes5

  • Signal wire shorted to ground through damaged insulation.
  • Internal short in the IAT sensor.
  • Water in the connector creating an unwanted electrical path.
  • Failed MAF sensor when the IAT sensor is built into it.
  • Engine computer fault (rare).

How to diagnose5

  1. Watch the IAT reading on a scan tool and compare it with outside air temperature.
  2. Unplug the sensor with the key on; if the reading flips to the lowest value, the short is most likely inside the sensor.
  3. If the reading stays high with the sensor unplugged, look for a short to ground in the signal wire.
  4. Inspect the connector for water or corrosion.
  5. Measure sensor resistance and compare with the manufacturer table.

How to fix5

  1. Dry, clean and reconnect the connector.
  2. Repair the damaged insulation on the signal wire.
  3. Replace the IAT sensor if the short is internal.
  4. Replace the MAF sensor if the IAT sensor is built into it.
  5. Clear the codes and confirm the temperature reading is close to outside air.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

The cost is low for a wire repair 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 low voltage mean high temperature?

Because this type of sensor loses resistance as it warms up, so the voltage the computer reads drops.

Does this code affect the engine?

Usually only slightly, since the computer uses a backup value, but fix it to avoid higher fuel use and hard starting.

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.

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