Ambient Temperature Sensor - Operation

OPERATION

The ambient temperature sensor is a variable resistor that operates on a five-volt reference signal. The resistance in the sensor changes as the temperature changes, changing the temperature sensor signal circuit voltage input to the Totally Integrated Power Module (TIPM). The TIPM reads the sensor input, then sends the appropriate electronic ambient temp sensor messages to the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN) over the Controller Area Network (CAN) data bus. The EMIC then displays the appropriate temperature information an electronic display unit.

The ambient temperature sensor as well as the hard wired inputs and outputs of the sensor may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the electronic controls and communication that provide some features of the ambient temperature display. The most reliable, efficient and accurate means to diagnose the electronic controls and communication related to ambient temperature display operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.