P0112: Intake Air Temperature Sensor 1 Circuit Low Input

Short answer: P0112 means “Intake Air Temperature Sensor 1 Circuit Low Input”. It is a standard OBD-II code, so the basic meaning is the same on every car. Below is what it means on each of the 6 cars we cover, with a link to the full page for each car.

Standard OBD-II code Same meaning on all cars (SAE J2012).

P0112 on each car

Symptoms

1. Check engine light on
2. There may be no noticeable symptoms of a
3. P0112
4. Indicator Lamp). However, a emissions test may reveal higher Nox readings depending
5. On the type of IAT failure. Or the engine may ping under load, depending on the
6. Type of IAT failure

Likely causes

1. Usually the P0112 is caused by a bad IAT (internally shorted or open or otherwise damaged)
2. But it could also be
3. No reference voltage to the IAT sensor due to an open wire
4. Excessively high intake air temperatures
5. Short to ground on signal circuit
6. Damaged IAT connector
7. Bad PCM

What to check, in order

1. Read the code and freeze-frame data with an OBD-II scanner
2. Check the connector and wiring of the part named in the code
3. Test the part with scanner live data or a multimeter, using the values in the repair manual
4. Fix the cause, clear the code and test-drive

Causes and checks above are the general meaning. The exact test steps and values differ by car: open your car’s page.

All fault codes