P0112Intake Air Temperature Circuit Low Input
The OBD2 code P0112 indicates that the engine control module (ECM) has detected a low voltage signal from the intake air temperature (IAT) sensor, suggesting a potential issue with the sensor or its circuit
Definition
Common causes
- Faulty intake air temperature sensor
- Open or shorted wiring in the intake air temperature circuit
- Poor electrical connections
- Corroded connectors
- Faulty engine control module (ECM)
- Vacuum leaks
- Damaged or disconnected intake air ducting
Common misdiagnoses
- Faulty Mass Air Flow (MAF) Sensor
- Faulty Engine Coolant Temperature (ECT) Sensor
- Vacuum Leaks
- Faulty Engine Control Module (ECM)
- Wiring Issues or Short Circuits
- Faulty Intake Air Temperature (IAT) Sensor
- Air Filter Restrictions
- Throttle Position Sensor (TPS) Issues
Troubleshooting steps
1.Check for Additional Codes
Use an OBD-II scanner to check for any other trouble codes that may be present. This can help identify if there are related issues
2.Inspect the IAT Sensor
Locate the IAT sensor, which is usually found in the intake manifold or air intake duct
3.Check for physical damage to the sensor or its connector
4.Ensure that the sensor is properly connected and that there are no bent pins or corrosion
5.Test the IAT Sensor
Use a multimeter to measure the resistance of the IAT sensor. Compare the readings to the specifications provided in the vehicle's service manual
6.If the resistance is outside the specified range, the sensor may be faulty and should be replaced
7.Check Wiring and Connectors
Inspect the wiring harness and connectors leading to the IAT sensor for any signs of damage, fraying, or corrosion
8.Look for any loose connections or broken wires that could cause a poor signal
9.Check for Short Circuits or Open Circuits
Use a multimeter to check for continuity in the wiring between the IAT sensor and the ECM
10.Check for any short circuits to ground or power that could affect the sensor's signal
11.Inspect the Air Intake System
Check for any obstructions or leaks in the air intake system that could affect the air temperature readings
12.Ensure that the air filter is clean and not clogged
13.Check Engine Coolant Temperature (ECT) Sensor
Sometimes, issues with the ECT sensor can affect the IAT readings. Check the ECT sensor for proper operation
14.Clear Codes and Test Drive
After performing the above checks and repairs, clear the trouble codes using the OBD-II scanner
15.Take the vehicle for a test drive to see if the code reappears
16.Consult a Professional
If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician for further diagnosis. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P0112 code