P0112 Code: Intake Air Temperature Sensor 1 Circuit Low
🟢 Low severity · drivable
You can usually drive, but expect worse fuel economy while the computer adds extra fuel.
What P0112 means
The IAT sensor signal is too low, which the computer reads as very hot air. The sensor or its wiring has a problem, often a short to ground. The engine may run rich and use more fuel.
Symptoms
- Check engine light on
- Poor fuel economy
- Engine runs rich
- Black exhaust smoke in severe cases
Common causes
- most common: Faulty IAT sensor
- common: Wiring shorted to ground in the sensor circuit
- less common: Corroded connector
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Replace the IAT sensor | Yes | $20–80 |
| Repair the wiring short to ground | Yes | $20–80 |
| Clean the connector | Yes | $0–20 |
Frequently asked questions
Can I drive with P0112?
Yes, but expect worse fuel economy because the computer thinks the air is hotter than it is and adds fuel.
What does a low IAT signal mean?
The sensor voltage is very low, which the computer reads as extremely hot intake air.
Should I replace the sensor first?
A bad sensor is the most common cause, but check the wiring for a short before buying parts.
Related codes
P0110
P0110 Code: Intake Air Temperature Sensor 1 Circuit
P0111P0111 Code: Intake Air Temperature Sensor 1 Range/Performance
P0113P0113 Code: Intake Air Temperature (IAT) Sensor Circuit High Input
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.