CONVERSION GP 3C8163 - Caterpillar

Illustration 4 g01401538
2-pin connector for the ambient air temperature sensor (1) Signal (2) Return
Connect a digital voltmeter between terminal 1 on the sensor connector and the ground strap for the ECM. Measure the DC signal voltage.
If the voltage is greater than 4.9 VDC, there is a problem with the return wire. If the voltage is less than 4.9 VDC, there is a problem with the signal wire. Check the appropriate wire for the following problems:
Cuts
Abrasion
Loose connectionsMake the necessary repairs.
Verify that the DC signal voltage is between 0.2 VDC and 4.9 VDC.STOP
A 172-4 code becomes active. - Repair: Perform the following procedure:
Measure the temperature of the air inlet temperature sensor with a laser infrared thermometer or equivalent.
If the temperature of the sensor is above 135 °C (275 °F), lower the temperature of the sensor by cooling the sensor. Connect the sensor to the engine harness. Use 7X-1710 Multimeter Probes to measure the signal voltage at the harness connector for the air inlet temperature sensor. Slide the probes into the harness connector in order to take the voltage measurement. Verify that the DC signal voltage is above 0.2 VDC.
If the temperature of the sensor is below 135 °C (275 °F), connect a new sensor to the engine harness. Use 7X-1710 Multimeter Probes to measure the signal voltage at the harness connector for the air inlet temperature sensor. Slide the probes into the harness connector in order to take the voltage measurement. Verify that the DC signal voltage is above 0.2 VDC.STOP