FUEL SYSTEM (DFI) 3-55

Inlet Air Temperature Sensor (Service Code 13)

Inlet Air Temperature Sensor Removal/Installation

CAUTION

Never drop the inlet air temperature sensor especially on a hard surface. Such a shock to the sensor can damage it.

•Remove the fuel tank (see Fuel Tank Removal).

•Disconnect the connector [A].

•Remove the screw [B].

•Pull out the inlet air temperature sensor [C].

•Put the inlet air temperature sensor into the air cleaner

housing.

•Tighten:

Torque - Inlet Air Temperature Sensor Screw: 0.80 N·m (0.081 kgf·m, 7.1 in·lb)

Inlet Air Temperature Sensor Output Voltage

Inspection

NOTE

○Be sure the battery is fully charged.

•Turn the ignition switch OFF.

•Remove the fuel tank (see Fuel Tank Removal).

•Disconnect the inlet air temperature sensor connector and connect the harness adapter [A] between these connectors as shown in the figure.

Main Harness [B]

Inlet Air Temperature Sensor [C]

Special Tool - Measuring Adapter: 57001-1700

•Connect a digital meter [D] to the harness adapter leads.

Inlet Air Temperature Sensor Output Voltage Connections to Adapter:

Digital Meter (+) → R (sensor G/Y) lead Digital Meter (–) → BK (sensor BR/BK) lead

•Measure the output voltage with the engine stopped and the connector joined.

•Turn the ignition switch ON.

Output Voltage

Standard: About DC 2.25 2.50 V at inlet air temperature 20°C (68°F)

NOTE

○The output voltage changes according to the inlet air temperature.

•Turn the ignition switch OFF.

If the reading is within the standard, check the ECU for its ground and power supply (see ECU Power Supply Inspection).

If the ground and power supply are good, replace the ECU (see ECU Removal/Installation).

3-56 FUEL SYSTEM (DFI)

Inlet Air Temperature Sensor (Service Code 13)

If the reading is out of the standard, remove the ECU and check the wiring for continuity between main harness connectors.

Special Tool - Hand Tester: 57001-1394

○Disconnect the ECU and sensor connectors.

Wiring Continuity Inspection

ECU Connector [A] ←→

Inlet Air Temperature Sensor Connector [B]

G/Y lead (ECU terminal 26) [C]

BR/BK lead (ECU terminal 28) [D]

If the wiring is good, check the inlet air temperature sensor resistance (see Inlet Air Temperature Sensor Resistance Inspection).

Inlet Air Temperature Sensor Resistance Inspection

•Remove the inlet air temperature sensor (see Inlet Air Temperature Sensor Removal/Installation).

•Suspend the sensor [A] in a container of machine oil so that the heat-sensitive portion is submerged.

•Suspend a thermometer [B] with the heat-sensitive portion [C] located in almost the same depth with the sensor.

NOTE

○The sensor and thermometer must not touch the container side or bottom.

•Place the container over a source of heat and gradually raise the temperature of the oil while stirring the oil gently for even temperature.

•Using a digital meter, measure the internal resistance of the sensor across the terminals at the temperatures shown in the following.

Inlet Air Temperature Sensor Resistance Standard: 5.4 6.6 kΩ at 0°C (32°F)

0.29 0.39 kΩ at 80°C (176°F)

If the reading is out of the standard, replace the sensor. If the reading is within the standard, but the problem still exists, replace the ECU (see ECU Removal/Installation).

FUEL SYSTEM (DFI) 3-57

Inlet Air Temperature Sensor (Service Code 13)

Inlet Air Temperature Sensor Circuit

1.Inlet Air Temperature Sensor

2.ECU