P0112 — Intake Air Temperature Sensor 1 Circuit Low
Drive with caution — fix soon.
What P0112 means
P0112 means the engine computer is reading an unusually low voltage from the Intake Air Temperature (IAT) sensor, which usually points to a wiring short, a bad connection, or a failed sensor. The IAT sensor tells the computer how warm or cold the incoming air is so it can fine-tune the fuel mixture. When the signal looks wrong, the computer ignores it and uses a fixed estimate instead, which can make the engine run slightly rich or lean.
Common symptoms
- Check Engine light is on
- Slightly rough idle or hesitation
- Reduced fuel economy
- Harder starting, especially when cold
- Occasional black smoke from the exhaust
Common causes
- Failed intake air temperature sensor
- Wiring short to ground in the sensor circuit
- Corroded or loose sensor connector
- Damaged or chafed wiring harness
- Water or oil contamination at the sensor
Typical repair cost
$90 – $220
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0112 code?
For short trips, usually yes, since the engine uses a backup temperature value to keep running. You may feel some rough idle or weaker fuel economy, though, so it's best to get it diagnosed soon rather than letting it drag on.
How much does it cost to fix a P0112?
Most repairs run between $90 and $220. If it's just the IAT sensor, the part is inexpensive, but tracing a wiring short or connector problem can add some labor time.
Is a P0112 code serious?
It's usually moderate rather than urgent. Your car won't be damaged immediately, but driving with a bad air-temperature reading can hurt fuel economy and emissions, so it shouldn't be ignored.
What's the difference between P0112 and P0113?
P0112 means the sensor signal is too low (often a short to ground), while P0113 means it's too high (often an open circuit or disconnected sensor). Both point to the same IAT sensor circuit, just opposite failures.