Heated Thermostat The thermostat is set to open when the coolant temperature reaches Cat the thermostat. Once the coolant has passed through the engine its temperature is approximately Cat the engine temperature sensor. If the ECM starts to regulate the system the ECM supplies an earth path for the heater element in the thermostat. This causes the element to expand and increase the opening dimension of the thermostat. The warmer the element the sooner the thermostat opens and the lower the resulting coolant temperature is. The thermostat regulates the coolant temperature in the range C to C. The expanding element in the thermostat is heated to a higher temperature than the surrounding coolant to generate the correct opening aperture. Should the coolant temperature exceed C the electrically heated thermostat is activated independently of the prevailing engine parameters. Should the heated thermostat fail, (fault codes will be stored in the ECM) the EMS will ensure the safe operation of the engine and the thermostat will operate as a conventional unit.
ENGINE MANAGEMENT SYSTEM – V 18-2-32 DESCRIPTION AND OPERATION ECM Adaptions The ECM has the ability to adapt the values it uses to control certain outputs. This capability ensures the EMS can meet emissions legislation and improve the refinement of the engine throughout its operating range. The components which have adaptions associated with them are: l The IACV l The APP sensor l The HOS l The MAF/IAT sensor l The CKP sensor l Electric throttle body.