P0110

CIRCUIT DESCRIPTION






The intake air temperature sensor is built into the air flow meter and senses the temperature of the intake air. A thermistor built into the intake air temp. sensor changes the resistance value according to the coolant temperature. The lower the intake air temperature, the greater the thermistor resistance value, and the higher the intake air temperature, the lower the thermistor resistance value. The intake air temp. sensor is connected to the Engine Control Module (ECM). The (5 volt) power source voltage in the ECM is applied to the intake air temp. sensor from the terminal THA via a resistor R. That is, the resistor R and the intake air temperature sensor are connected in series. When the resistance value of the intake air temperature sensor changes in accordance with changes in the intake air temperature, the potential at terminal THA also changes. Based on this signal, the ECM increases the fuel injection volume to improve driveability during cold engine operation.

NOTE: If the ECM records the DTC P0110, it operates the fail safe function, in which the intake air temperature is assumed to be 20°C (68°F).




HINT: After confirming DTC P0110 use the OBD II scan tool or LEXUS hand-held tester to confirm the intake air temperature from CURRENT DATA.






WIRING DIAGRAM

Intake Air Temperature Sensor Circuit:

INSPECTION PROCEDURE
HINT: If DTCs PO11O (Intake air temp. circuit malfunction), PO115 (Engine coolant temp. circuit malfunction), PO120 (Throttle position circuit malfunction) are output simultaneously, E2 (Sensor ground) may be open.