Air Temperature Sensor ( Ambient / Intake ): Testing and Inspection

Air Temperature Sensor Schematic:

A faulty air temperature sensor will set code 26 in the on-board diagnostic system. Refer to the schematic diagram and test the sensor with the diagnostic chart.

Wire color code identification:

L: Blue
B: Black
Y: Yellow
G: Green
R: Red
W: White
Br: Brown
Lg: Light green
Gr: Gray

Air Temperature Sensor Diagnostic Chart:

AIR TEMPERATURE SENSOR DIAGNOSTIC CHART

Pressure Sensor Harness:

CHECK VOLTAGE AND RESISTANCE

1. With ignition "ON" and engine not running, measure voltage across ECU connector terminals as follows:

Connector & terminal: Voltage:
(F121)6-(F121)1 0.15-4.85V
(F121)6-(F121)2 0.15-4.85V

2. With ignition "OFF," disconnect ECU connector and measure resistance between ECU connector and sensor connector as follows:

Connector & terminal: Resistance:
(F121)6-(F113)2 Below 1 Ohm
(F121)1-(F113)1 Below 1 Ohm
(F121)2-(F113)1 Below 1 Ohm

3. Measure resistance between ECU connector terminal (F121)6 and ground. It should be infinite.

Air Temperature Sensor Testing:

CHECK AIR TEMPERATURE SENSOR

1. With ignition switch "OFF," disconnect sensor connector.
2. Measure resistance between sensor terminals (F113)1 and (F113)2 for these resistance values:

Resistance: Temperature:
2 - 3K Ohms 20° C (68° F)
270 - 370 Ohms 80° C (176° F)