The P0112 diagnostic trouble code (DTC) indicates that the Engine Control Unit (ECU) has detected a low voltage signal from the Intake Air Temperature (IAT) sensor circuit.
The IAT sensor measures the temperature of the air entering the engine. This information helps the ECU determine the proper fuel injection amount and ignition timing.
When the sensor sends a signal lower than expected, the ECU stores the P0112 code and usually triggers the Check Engine Light.
Why the IAT Sensor Is Important
The Intake Air Temperature sensor helps the engine control system adjust combustion parameters.
It helps calculate:
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air density
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fuel injection timing
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ignition timing adjustments
-
emission control
Incorrect readings may cause the engine to run too rich, increasing fuel consumption and emissions.
Common Causes of the P0112 Code
Several issues may cause this fault.
Faulty IAT sensor
A damaged or worn sensor may send incorrect low-voltage signals.
Short circuit in wiring
A short to ground in the sensor wiring can produce a low input signal.
Corroded connectors
Poor electrical contact may affect signal transmission.
Dirty air intake system
Contamination around the sensor may affect its operation.
Faulty ECU (rare)
In rare cases, the ECU may incorrectly interpret the signal.
Symptoms of the P0112 Code
Drivers may experience the following symptoms:
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Check Engine Light
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rough engine idle
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poor acceleration
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increased fuel consumption
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reduced engine efficiency
Some vehicles may also experience engine hesitation during acceleration.
How to Diagnose P0112
Diagnosing this issue requires several steps.
Step 1 – Scan the vehicle
Confirm the P0112 code using an OBD2 scanner and check for related codes such as:
-
P0110
-
P0111
-
P0113
Step 2 – Inspect the IAT sensor
Check the sensor location in the intake system and inspect it for damage or contamination.
Step 3 – Inspect wiring and connectors
Look for damaged wires, loose connectors or corrosion.
Step 4 – Test sensor voltage
Using a multimeter, verify that the voltage signal from the sensor is within specification.
Repair Solutions for P0112
Common repair solutions include:
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replacing the intake air temperature sensor
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repairing damaged wiring
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cleaning the sensor
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replacing corroded connectors
Most cases are resolved by replacing the IAT sensor.
Estimated Repair Cost
Typical repair costs include:
| Repair | Estimated Cost |
|---|---|
| IAT sensor replacement | $80 – $200 |
| Wiring repair | $100 – $250 |
| Connector replacement | $50 – $150 |
Can You Drive With Code P0112
Driving with P0112 is possible for short distances, but it may cause inefficient engine operation.
Ignoring the problem may lead to:
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increased fuel consumption
-
poor engine performance
-
higher emissions
Repairing the issue quickly is recommended.
FAQ – P0112 Code
What does P0112 mean
The P0112 code indicates a low voltage signal from the intake air temperature sensor circuit.
Can a bad IAT sensor cause P0112
Yes. A faulty IAT sensor is the most common cause.
Is P0112 serious
It is usually moderately serious, as it affects engine efficiency.
How do you fix P0112
Start by checking the IAT sensor and its wiring connections.
✍️ Author: Bejenaru Alexandru Ionut – [email protected]
🔗 Internal link: https://diagnozabam.ro/sfaturi
