COMBUSTION TYPE POWER HEATER SYSTEM SYSTEM DESCRIPTION

  1. GENERAL

    1. While the 1ND-TV engine offer excellent combustion efficiency, they generate less heat. Therefore, depending on the operating condition, the engine coolant temperature remains low, making it difficult to ensure the proper heating effect. Thus, in order to provide adequate heating effect, a combustion type power heater is provided as optional equipment on cold area specification models.

    2. This heater system provides a combustion type power heater between the engine and the heater core. Air and fuel are introduced into the heater's combustion chamber, and a glow plug is used to ignite this mixture. By heating the water that flows around the combustion chamber, this system ensures the heating effect.

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  2. HEATER ASSEMBLY

    1. This system, which consists of a heater assembly, heater switch assembly, and a heater pump assembly, operates when the engine is running and the heater switch assembly is turned on.

      • The heater assembly consists of an ECU, flame sensor, surface sensor, control overheating sensor, glow plug, and air blower motor. It cannot be disassembled.

      • The ECU in the heater assembly controls this system in accordance with the signals received from the sensors and switches.

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  3. OPERATION

    1. When the engine is operating, turning the heater switch assembly on causes the air blower motor to operate for several seconds for verification purposes. Then, the glow plug starts to preheat the combustion chamber. After that, the fuel pump and air blower motor turn on in order to start low combustion. The fuel pump speed is then increased in steps, and this is accompanied by a gradual increase in the speed of the air blower motor, thus leading to high combustion.

    2. When the ignition switch is turned off or the heater switch assembly is turned off, the fuel pump stops, causing the combustion to stop. For the purpose of after-purge, current is applied again to the glow plug, and the air blower motor is activated for several seconds. Then, the entire system comes to stop.

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    3. While the system is operating, it controls the fuel pump speed and switches between high combustion and low combustion, and always keeps the coolant temperature between 67°C (152.6°F) and 80°C (176°F). If the coolant temperature exceeds 80°C (176°F), the fuel pump stops automatically to stop combustion. Thereafter, when the coolant temperature reaches 67°C (152.6°F) or lower, ignition occurs again. The operation of the glow plug, air blower motor and fuel pump during extinguishing and igniting is the same as when these are operated by switching as mentioned previously.

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