Increased Idle Speed Setup Important: The presented proposal does not cover all the diversity of vehicle manufacturer implementations. An adaptation to each application will be required. A careful review of your vehicle documentation is advised. The IIS signal has been implemented as a low-side transistor - this means that, when the signal is active, the associated pin XG3-H1 is internally grounded (conducting condition). Otherwise, the pin is in high-impedance condition (blocking condition). Please refer to your unit schematic for further details. Concept This function is beneficial to improve the refrigeration performance during long periods of vehicle running in idle (eg.
Traffic jam, urban distribution with high density of traffic lights, etc.) The alternator maximum capacity is obtained at maximum engine rpm. When running in idle, the maximum power is approximately 60% of the rate power. Some vehicles incorporate a digital or analog input that can used to increase the idle speed. The Gateway Controller (GC) has a digital output (IIS signal) that indicates that the refrigeration units demand is higher than the alternator can provide. The IIIS signal can be then used to “tell” the vehicle ECU to increase the idle speed in order to increase the power delivered.
Check the vehicle documentation if the vehicle is equipped with such a feature and how to integrate into their circuitry. The IIS signal goes active when the Gateway goes to POWER DERATING mode. This state can be identified by a triangle oriented downwards. The IIS signal it is cleared when the Compressor Drive Module (CDM) becomes inactive. eg when the unit goes to NULL mode. TK 56881-18-IM-EN 27