OBD-II Code P0112 is a diagnostic trouble code that indicates a low input from the Intake Air Temperature (IAT) Sensor. This sensor plays a critical role in measuring the temperature of the air entering the engine, which is essential for the engine control module (PCM) to manage fuel efficiency and engine performance effectively.
What Does the P0112 Code Mean?
The P0112 code is defined as Intake Air Temperature Circuit Low Input. It means that the voltage signal sent to the PCM from the IAT Sensor stays below 0.5 volts when it should be fluctuating within an appropriate range corresponding to the coolant temperature readings. This condition suggests a fault in the IAT circuit or sensor itself.
What Causes the P0112 Code?
There are several potential causes for the P0112 code, including:
- Defective Intake Air Temperature Sensor
- Dirty air filter
- Faulty Mass Air Flow Sensor
- Corroded or damaged wiring and connections related to the IAT Sensor
What Are the Symptoms of the P0112 Code?
The symptoms associated with the P0112 code can include:
- Illuminated Check Engine Light
- Hard starting of the engine
- Poor fuel economy
- Poor engine performance or hesitation during acceleration
How Serious Is the P0112 Code?
While the P0112 code is classified as a moderate severity issue, it does not pose an immediate threat to vehicle safety or functionality. However, it is advisable to diagnose and repair the problem within a reasonable timeframe to maintain optimal vehicle performance and prevent further issues.
How to Diagnose the P0112 Code
Diagnosing the P0112 code involves several steps:
- Record the freeze frame data to understand the conditions under which the code was set.
- Conduct a test drive to replicate the code-setting conditions while monitoring engine load, throttle position, RPM, and road speed using a data streaming scan tool.
- Compare the IAT sensor readings to the coolant temperature readings, ensuring they rise and fall in tandem.
- Check the IAT sensor connector for a steady 5-volt reference voltage and a good ground.
- Perform a voltage output test of the IAT sensor using a heat source, such as a heat gun, to observe changes in sensor readings.
Common Repairs for the P0112 Code
Common repairs for the P0112 code may include:
- Replacing the faulty Intake Air Temperature Sensor
- Cleaning or replacing a dirty air filter
- Repairing or replacing corroded wiring or connectors in the IAT circuit
- Replacing a defective Mass Air Flow Sensor if identified as the root cause
How Much Does It Cost to Fix the P0112 Code?
The cost to fix the P0112 code can vary widely based on the underlying issue and labor rates in your area. Typical repair costs can range from $100 to $400, depending on whether you need to replace the IAT sensor or perform more extensive repairs like wiring harness replacements.
Can I Fix the P0112 Code Myself?
Yes, if you have basic automotive repair skills and tools, you can troubleshoot and potentially fix the P0112 code yourself. Start by inspecting the IAT sensor and its connections, cleaning the air filter, and checking for any visible damage to the wiring. However, if you are not comfortable with electrical diagnostics or repairs, it is advisable to seek professional assistance.
