Circuit/System Description
The engine control module (ECM) commands the speed of the cooling fans based on cooling requirements. The ECM controls the cooling fan speed by commanding the cooling control module. The cooling fan control module supplies separate power and ground circuits for each cooling fan. The ECM sends a pulse width modulated (PWM) signal to the cooling fan control module. The cooling fan control module interprets the signal and operates the cooling fans at the commanded speeds.
The engine control module (ECM) uses the engine coolant temperature sensor to monitor the engine for an over-temperature condition. This condition occurs when the coolant temperature is above a calibrated value. The ECM will alternately disable 2 groups of cylinders by turning OFF the fuel injectors. By switching between the 2 groups of cylinders, the ECM is able to reduce the temperature of the coolant.
The engine cooling fan system is composed of two electric cooling fans. The engine control module (ECM) controls the fan speed by sending a pulse width modulated (PWM) signal to the cooling fan control modules. The cooling fan control module varies the voltage drop across the cooling fan motor in relation to the pulse width modulated signal, which enables cooling fan operation at variable speeds. The cooling fan control module is thermally protected to prevent module damage in the case of a short circuit condition in the cooling fan motor.
The engine cooling fan system is composed of two electric cooling fans. The engine control module (ECM) controls the fan speed by sending a pulse width modulated (PWM) signal to the cooling fan control modules. The cooling fan control module varies the voltage drop across the cooling fan motor in relation to the pulse width modulated signal, which enables cooling fan operation at variable speeds. The cooling fan control module is thermally protected to prevent module damage in the case of a short circuit condition in the cooling fan motor.
The optional coolant heater is a 1, 000 watt heating element that mounts in the engine block in place of an existing anti-freeze plug. The coolant heater operates using an external 110 volt AC power source and is designed to warm the coolant in the engine block, for improved starting in very cold weather. The coolant heater also helps reduce fuel consumption when a cold engine is warming up. The detachable AC power cord allows the coolant heater to operate at all temperatures whenever it is connected to an AC power source. The power cord is also equipped with a weather shield to protect the plug when not in use.