P0112 Code Meaning and Next Steps

First checks take 10 to 15 minutes for the first checks. No special tools are usually needed for the first checks.

Can you keep driving?

Stop driving if any of these apply

!The engine starts running much worse, stalls, or the warning light flashes.
!The vehicle begins to overheat or lose power sharply while the code is active.

If the light is steady and the vehicle still drives normally: Often yes for a short time, but it should not be ignored.

What to check first

Step-by-step checks

1
Free - no tools
Check the IAT connector, harness, and nearby wiring for damage or corrosion
2
Free - no tools
Compare the live IAT reading to the ambient temperature when the engine is cold
3
Basic tool needed
Inspect the intake path for anything that could affect the sensor reading or the connector fit
4
Basic tool needed
If the sensor is integrated with another unit, make sure you are testing the right circuit before buying parts
5
Basic tool needed
If other air-fuel codes are present, consider them part of the same diagnosis

If the code returns

-If the reading is unrealistically cold, circuit testing becomes more important than another visual check.
-If unplugging or moving the harness changes the reading, the wiring side moves higher on the list.
-If the code returns after a sensor replacement, revisit the connector and reference circuit before assuming the new part is wrong.

Background

What this code means

P0112 is a generic OBD-II intake air temperature sensor code.

A low signal usually points to the sensor, its wiring, or a circuit fault that makes the reading look colder than it should.

Hard starting when cold or fuel trims that look off can appear when the intake temperature signal is too low.

Diagnosis

Common causes

Most common

Shorted IAT sensor

The sensor can report colder than ambient if it has failed internally.

Common

Wiring short or connector issue

A short to ground or poor connection can pull the signal low.

Common

Water or contamination

Moisture in the connector can distort the signal.

Possible

Shared circuit fault

The sensor may be fine but the circuit feeding it is not.

Avoid these mistakes

What not to do

xDo not replace the sensor first if there is an obvious wiring, connector, or intake issue.
xDo not ignore drivability changes just because the code sounds like a sensor problem.

Parts

Parts that may need replacing

PartTypical costNotes

Intake air temperature sensor$20-$80Relevant when the signal is clearly low and the circuit tests poorly.

Connector or pigtail repair$15-$90Worth checking if there is corrosion or a loose fit.

Intake duct repair$10-$70Relevant if the sensor area has obvious damage or water intrusion.

Related OBD codes

P0111

P0111 usually means the intake air temperature signal is out of the expected range.

P0113

P0113 usually means the intake air temperature signal is reading too high.

P0101

P0101 usually means the mass airflow signal is outside the expected range or performance window.

Source notes

Generic OBD-II (SAE J1979 / ISO 15031-5). P0112 was expanded around common low IAT signal faults, including shorts, connector issues, and contamination.

This guide is written as a generic multi-make reference, so bulletin history, sensor locations, and repair order can still change by manufacturer and engine family.

This is generic OBD-II guidance and should not override vehicle-specific service information. Exact diagnosis and repair steps vary by make, engine family, and model year.

Last reviewed: 2026-04-10

Reference: Open reference

P0112 - P0112 Usually Means the Intake Air Temperature Signal Is Reading Too Low