Error Code P0114 is described as Intake Air Temperature (IAT) Circuit Intermittent. It’s a generic error code which indicates that the PCM (powertrain control module, sometimes referred as ECM or engine control module) has recorded an intermittent or erratic voltage signal from the IAT.
It is associated with error codes P0111, P0112 and P0113.
An IAT sensor is built into the MAF (Mass Airflow Sensor) sensor (or for some vehicles, it is mounted to air filter duct housing). This sensor detects the intake air temperature (rise and fall of air temperature) and transmits that information to the PCM. It comes with a thermistor, a device sensitive to changes in the temperature. The PCM then uses this data to control many aspects of the engine’s emission control system, including fuel ratio, and ignition spark timing.
Most vehicles use a reference voltage of 5V and a ground signal to complete the circuit of IAT sensor, making a two-wire thermistor sensor. Changes in the resistance levels in the IAT sensor element will cause fluctuations in the voltage of the input circuit. The PCM reads the fluctuations as changes in the air temperature.
If the PCM detects intermittent signals from the IAT sensor, throughout a set period of time, then it will trigger the Error Code P0114. This erratic voltage signal is usually caused by a fault in the wiring, poor connection, problem in the IAT or the PCM itself (though rare).
This error code puts the PCM into failsafe mode and activates the Check Engine light. Other common symptoms include:
- Hard starting
- Increase in fuel consumption
- Black smoke emission from the exhaust
- Engine running lean or may have pre-ignition
- Poor engine performance, hesitation on acceleration
The erratic and intermittent problem of the IAT is usually caused by shorting and open circuit, wiring or connectors. Other common causes include:
- Defective IAT sensor
- Dirty and/or clogged air filter
- Defective MAF sensor
- Corroded or faulty IAT sensor wiring or connectors
- Broken intake air inlet pipe
How to Check
As with other error codes, it is important to record the freeze frame rate data and replicate the conditions when the error code was set to a test drive. A qualified mechanic will use his data streaming scan tool and pay close attention to the engine load, RPM, throttle position, and road speed. When driving the vehicle, values will be compared to Intake Air Temperature sensor parameter ID. The Intake Air Temperature sensor voltage values should rise and fall depending on the changes in engine temperature. He will then compare the IAT readings to the readings from the Coolant Temperature sensor, which should move in tandem with each other. The temperature of engine coolant sensor will have a slightly higher range.
With key on, engine off, the IAT sensor connector must be checked. There should be 5V reference volt age and a good ground. Find your vehicle’s proper engine performance wiring diagram to determine the proper color and position of these connectors and wires.
How to Fix
As with most error codes associated with the IAT sensor, the repair for P0114 is pretty simple.
- The easiest thing you can do is to check whether the IAT connector needs fixing or replacement for short or open circuit caused by carrion damages.
- Repair or replace wiring to fix shorted or open circuits in the harness.
- If you have determined that your IAT sensor is faulty, then it needs replacement.
As said earlier, this error code will put the PCM to failsafe mode, and depending on the make and model of the vehicle, the failsafe strategy may vary, causing erratic drivability issues. Driving a vehicle for extended period of time while on failsafe mode may cause bigger ignition problems, which would definitely require a more thorough repair.