PIN-G.E.T. 4T4708 - Caterpillar

Illustration 1 g02380096
(1) Intake air temperature sensor Diagnostics
Illustration 2 g02515276
Partial Electrical Schematic
(A) Connector
(C) Connector
(CC) Connector
(K) Connector
(1) Intake air temperature sensor
(2) Control panel
Disconnect intake air temperature sensor (1) connector from connector (K). Measure the value of the resistance in the intake air temperature sensor. See "Specifications" below for the correct resistance value. Proceed to Step 2.
If the resistance value is incorrect, see Step 3. If the resistance value is correct, see Step 4.
Replace the intake air temperature sensor.
Measure the voltage between the "GN/YL" wire and the "BR/WH" wire at connector (K). See "Specifications" below for the correct voltage. Proceed to Step 5.
If the voltage value is incorrect, see Step 6. If the voltage value is correct, see Step 7.
Disconnect connector (C) from connector (CC). Check the wiring harness between connector (K) and connector (C). Repair the wiring harness if faulty. Also, check the system power source. Refer to Systems Operation, "Air Conditioning System Electrical Schematic".
Reconnect the intake air temperature sensor connector to connector (K). Measure the voltage between "GN/YL" wire and the "BR/WH" wire at connector (CC). See "Specifications" below for the correct voltage. Proceed to Step 8.
If the voltage values are incorrect, see Step 9. If the voltage values are correct, see Step 10.
Disconnect connector (A) from control panel (2). Check the wiring harness between connector (CC) and connector (A). Repair the wiring harness if faulty.
Reconnect connector (C) to connector (CC). Measure the voltage between the "GN/YL" wire and the "BR/WH" wire at control panel (2). If the voltage value is incorrect, replace the control panel. Specifications
Illustration 3 g02316016
Intake Air Temperature Sensor Characteristics
(R) Resistance (k Ohms)
(T) Temperature (Inside cab) Resistance in the intake air temperature sensor 0° C (32° F) ... 7.2k Ohms 25° C (77° F) ... 2.2k OhmsVoltage between connectors ... 5 VDC