DTC 0401

Intake Air Temperature Sensor (DTC: 0401)
The intake air temperature sensor is mounted to the air duct (behind front turn signal lamp RH). The sensor detects intake air temperature and transmits a signal to the ECM.
The temperature sensing unit uses a thermistor, which is sensitive to the change in temperature. Electrical resistance of the thermistor decreases in response to the temperature rise.
This sensor is not used to control the engine system. It is used only for the on board diagnosis.




DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE
Procedure for malfunction A

With Consult
1) Turn ignition switch "ON".




2) Select "DATA MONITOR" mode with CONSULT
3) Wait at least 5 seconds.

OR

With GST
1) Turn ignition switch "ON" and wait at least 5 seconds.




2) Select MODE 3 with GST.

OR

Without Scan Tools
1) Turn ignition switch "ON" and wait at least 5 seconds.
2) Turn ignition switch "OFF", wait at least 5 seconds and then turn "ON".
3) Perform diagnostic test mode II (Self-diagnostic results) with ECM.

Procedure for malfunction B

With Consult
1) Lift up vehicle and open engine hood.
2) Wait until engine coolant temperature is less than 90°C (194°F).
(a) Turn ignition switch "ON".
(b) Select "DATA MONITOR" mode with CONSULT
(c) Check the engine coolant temperature.
(d) If the engine coolant temperature is not less than 90°C (194°F), turn ignition switch "OFF" and cool down engine.
Perform the following steps before engine coolant temperature is above 90°C (194°F).
3) Turn ignition switch "ON".
4) Select "DATA MONITOR" mode with CONSULT.
5) Start engine.
6) Shift selector lever to "D" position (A/T), or set shift lever to 4th gear position (M/T).
7) Hold vehicle speed at 70 to 80 km/h (43 to 50 MPH) for 2 minutes.

OR

With GST
1) Lift up vehicle and open engine hood.
2) Wait until engine coolant temperature is less than 90°C (194°F).
(a) Turn ignition switch "ON".
(b) Select MODE 1 with GST.
(c) Check the engine coolant temperature.
(d) If the engine coolant temperature is not less than 90°C (194°F), turn ignition switch "OFF" and cool down engine.
Perform the following steps before engine coolant temperature is above 90°C (194°F).
3) Start engine.
4) Shift selector lever to "D" position (A/T), or set shift lever to 4th gear position (M/T).
5) Hold vehicle speed at 70 to 80 km/h (43 to 50 MPH) for 2 minutes.
6) Select MODE 3 with GST.

OR

Without Scan Tools
1) Lift up vehicle and open engine hood.
2) Wait until engine coolant temperature is less than 90°C (194°F).
(a) Turn ignition switch "ON".




(b) Check voltage between ECM terminal (59) and ground.

Voltage: More than 1.0 (V)

(c) If the voltage is not more than 1.0 (V), turn ignition switch "OFF" and cool down engine.
Perform the following steps before the voltage is below 1.0V.
3) Start engine.
4) Shift selector lever to "D" position (A/T), or set shift lever to 4th gear position (M/T).
5) Hold vehicle speed at 70 to 80 km/h (43 to 50 MPH) for 2 minutes.
6) Turn ignition switch "OFF", wait at least 5 seconds and then turn "ON".
7) Perform diagnostic test mode II (Self-diagnostic results) with ECM.




WIRING DIAGRAM




DIAGNOSTIC PROCEDURE

COMPONENT INSPECTION
Intake air temperature sensor










Check resistance as shown in the figure.