P0112 Technical Description
Intake Air Temperature Circuit Low Input
If you’re seeing the P0112 trouble code flash up on your dashboard, you’re likely searching for what it means and how you can fix it.
This guide will cover everything from symptoms to solutions.
In my years as a mechanic, I’ve fixed the P0112 issue more times than I can count.
In this article, we’ll explore why the P0112 code appears and what it indicates about your vehicle’s intake air temperature sensor. We’ll also discuss the common symptoms and step-by-step fixes.
Ready to roll up our sleeves and tackle this? Let’s get to work.
Key Takeaways
- P0112 Code Explained: Indicates a low input problem with the Intake Air Temperature (IAT) sensor.
- Common Symptoms: Includes poor fuel economy, rough idling, engine misfires, and difficulty starting.
- Potential Causes: Ranges from a faulty IAT sensor, bad electrical connections, to air intake leaks.
- Diagnostic Steps: Check the IAT sensor, inspect wiring, and test sensor functionality with a multimeter.
- Fixing the Issue: Often involves replacing the IAT sensor and ensuring all connections are secure and intact.
- Maintenance Tips: Regular checks on the sensor and electrical connections can prevent future occurrences of the P0112 code.
Table of ContentsShow
What Does the P0112 Trouble Code Mean?
The P0112 trouble code is an indicator that there’s a problem with the Intake Air Temperature (IAT) sensor in your vehicle.
Specifically, this code is triggered when the IAT sensor sends a voltage input to the vehicle’s computer that is lower than expected, which is often significantly colder than the actual ambient air temperature entering your engine.
Why does this matter?
Well, the IAT sensor plays a crucial role in your vehicle’s engine management system by monitoring the temperature of the air entering the engine.
The engine control unit (ECU) uses this temperature data to adjust the air-fuel mix and ignition timing.
Cold air is denser than warm air and requires more fuel to maintain a balanced mixture.
When the IAT sensor reports that the air is colder than it truly is, the ECU responds by richening the mixture unnecessarily. This can lead to a variety of performance issues.
When the P0112 code appears, it suggests that the sensor might be failing, or there could be a wiring problem affecting the sensor’s ability to accurately report air temperature.
The misreading can lead to decreased fuel efficiency, as the engine might consume more fuel than required.
It can also cause the engine to run rough, stall, or exhibit difficulty starting, especially in cold conditions where precise air-fuel mixtures are critical for proper engine operation.
Understanding this code is essential because it helps you identify and rectify a potential issue that can affect the overall performance and health of your engine.
Ignoring the P0112 code can lead to more significant engine problems, higher emissions, and failed emissions tests due to improper air-fuel mixtures and incomplete combustion.
By addressing this issue promptly, you ensure that your vehicle runs optimally and maintains efficiency.
P0112 Trouble Code Symptoms
When the P0112 code is active, your vehicle may exhibit several noticeable symptoms, including:
- Check Engine Light is On: The most apparent symptom that alerts you to the P0112 code.
- Poor Fuel Economy: The vehicle consumes more fuel due to incorrect air-fuel mixture adjustments.
- Rough Idling: The engine may run unevenly or stall during idle.
- Engine Misfires: Improper air-fuel mix can cause the engine to misfire, especially under load.
- Hard Starts: Difficulty in starting the engine, particularly in cold conditions.
- Decreased Engine Performance: Overall reduction in power and responsiveness.
- Failed Emissions Test: Due to improper combustion and increased emissions.
P0112 Trouble Code Causes
The P0112 trouble code can be triggered by several different issues within your vehicle’s intake air temperature system:
- Faulty Intake Air Temperature Sensor: The most common cause where the sensor itself is malfunctioning.
- Poor Electrical Connections: Damaged or loose connections at the IAT sensor can cause incorrect readings.
- Shorted or Open Wiring: Issues in the wiring harness leading to or from the IAT sensor.
- Corrosion at Sensor Connector: Corrosion can interrupt the sensor’s ability to transmit accurate data.
- Problems with the ECU: Rare, but faults in the engine control unit can manifest as sensor issues.
- Air Intake System Leak: Leaks can allow unmeasured, cold air to enter, affecting sensor readings.
How To Fix A P0112 Trouble Code
Fixing a P0112 trouble code involves a few diagnostic and repair steps to ensure that the issue is correctly identified and resolved. Here’s how you can tackle it:
1. Inspect the Intake Air Temperature Sensor
Start by checking the IAT sensor itself. Look for any signs of damage or corrosion on the sensor and its connector. Ensure the sensor is securely connected and that the connector pins are clean and in good condition.
2. Check the Wiring
Examine the wiring leading to the IAT sensor. Look for any signs of fraying, corrosion, or breaks. Pay special attention to the wiring harness for shorts or disconnections that could affect the sensor’s operation.
3. Test the Sensor
Use a multimeter to test the IAT sensor’s resistance. Compare your findings with the specifications in your vehicle’s service manual. An out-of-specification resistance reading indicates a faulty sensor that needs replacement.
4. Verify the Air Intake System
Ensure there are no leaks in the air intake system. Leaks can introduce extra air into the system, leading to erroneous sensor readings. Check all clamps, hoses, and the air filter housing for proper sealing.
5. Replace the Sensor if Necessary
If your diagnostic tests indicate a malfunctioning IAT sensor, replace it. Sensors are generally affordable and can be swapped out relatively easily.
6. Clear the Trouble Code
After repairs, clear the P0112 code from the ECU with an OBD-II scanner. This reset will turn off the check engine light and allow you to check if the issue reoccurs.
7. Road Test the Vehicle
Finally, take your vehicle for a test drive to ensure that it operates normally and the P0112 code does not reappear. Monitor the vehicle’s performance and check engine light during the test.
By methodically following these steps, you can effectively address the P0112 trouble code and restore your vehicle’s performance and efficiency.
Conclusion
Now that you’ve got the scoop on what P0112 means and how to fix it, you’re set to tackle it head-on.
Ever had to replace an IAT sensor before? How did it go?
Drop a comment below and share your experience or tips on dealing with P0112 or similar issues.
