Circuit description: Notes

Inlet temperature sensor, which is built into the intake air flow meter SUB-ASSY, detects intake air temperature. The resistance of the thermistor built into the inlet air temperature sensor changes as the intake air temperature varies. The lower the intake air temperature, the greater the thermistor resistance, and the higher the intake air temperature, the lower the thermistor resistance. The inlet air temperature sensor is connected to the engine control computer. The 5-V power supply voltage is supplied from THA terminal of the computer, and grounded in the computer via the resistor integrated into the inlet air temperature sensor. Therefore, since the resistor and the inlet air temperature sensor are connected in series, the resistance changes as the inlet air temperature changes, and the potential at the THA terminal also changes. Based on this signal, the engine control computer increases the fuel injection amount to improve driveability when the engine is cold.

NOTE: When either of these DTCs is stored, the engine control computer enters fail-safe mode. The engine control computer fixes the inlet air temperature at 20°C {68°F} during the fail-safe mode operation. The engine control computer continues fail-safe mode operation until the normal condition is restored.

DTC No.	DTC detection condition	Suspected parts
P0112	The voltage for the inlet air temperature sensor is less than 0.400V for 0.5 seconds or more. (1 trips detection logic)	Open or short condition in inlet air temperature sensor circuit Inlet air temperature sensor (integrated into intake air flow meter SUB-ASSY) ECM
P0113	The voltage for the inlet air temperature sensor is 4.707 V or more for 0.5 seconds or more. (1 trips detection logic)