On DDEC III/IV engines there is an Air Temperature Sensor (ATS) mounted to the bottom of the intake manifold. The ATS sends an electrical signal to the ECM indicating the inlet manifold temperature of the air entering the engine. The ECM uses this information to adjust gas flow, control air fuel ratio and in some cases fan control. The ATS provides necessary input to vary hot idle speed and injection timing resulting in improved cold starts and reduced white smoke. See Figure 27804 and see Figure 36033 .
1. Intake Manifold
2. Air Intake Sensor
Air Temperature Sensor (All Diesel Except Heat Exchanger-Cooled Pleasure Craft Marine)
9. CAC Matrix
10. Housing Lower
5. Seal Ring
12. Seal Ring
13. Air Temperature Sensor
7. Housing Upper
Air Temperature Sensor (Heat Exchanger-Cooled Pleasure Craft Marine)
The Series 60G natural gas engine air temperature sensor (ATS) is installed into the air inlet tube. See Figure 27920 . The ATS sends an electrical signal to the ECM indicating air inlet temperature. The ECM uses this information to adjust gas flow and control air fuel ratio.
The ATS is non-serviceable, and is replaced as a unit. No adjustment is required.
Remove the ATS as follows:
Install the ATS as follows:
Overtightening will distort and crack the sensor body, resulting in sensor malfunction. Damage may not be evident until sensor removal, when body may break apart.
Note: Because of its plastic body, the ATS must be hand started and carefully tightened.