GLOW CONTROL <4M40>
The self-regulating glow system is essentially the same as the one for the conventional 4D56-
SOHC engines.
System Configuration Diagram
Control System Diagram
Glow Control Unit Input / Output Pin Arrangement
1 Power source 2 Ignition switch-ST
3 Glow indicator lamp 6 Alternator L terminal
7 Glow plug relay 10 Glow-ECU earth
13 Engine coolant temperature sensor
SENSOR
IGNITION SWITCH IG1
The ignition switch IG1 supplies the power source
to the control unit and detects whether the ignition
switch is turned on or off.
The control unit begins to carry out the control as
soon as this signal is input.
IGNITION SWITCH ST
The ignition switch ST detects the engine is
cranking.
The control unit carries out the preheating control
during cranking when this signal is input.
ALTERNATOR "L" TERMINAL
The alternator "L" terminal detects the starting is
completed by increasing the alternator "L"
terminal voltage.
The control unit carries out the afterglow control
when the high signal is input.
ENGINE COOLANT
TEMPERATURE SENSOR
The control unit determines the engine warm-up
state by the output voltage of the engine coolant
temperature sensor and decides whether the
preheating control and the afterglow control are
required or not.
ACTUATOR
SELF-CONTROL TYPE GLOW
PLUG
Current is flowing through the glow plug and then
the glow plug temperature increases. After that,
the resistance of the temperature control coil built
in the glow plug increases. This allows the current
to decrease and the heat generation of the
heating coil to be restrained. The temperature of
the glow plug which the current is flowing through
is almost constant.
GLOW PLUG RELAY
The glow plug relay is the relay that applies the
battery voltage to the glow plug. When this relay
is turned to the "ON" position, the glow plug
temperature immediately increases. The control
unit carries out the preheating control by
controlling this relay.
GLOW CONTROL
When the ignition switch is turned to the "ON" position, the power source is supplied to the
control unit. The control unit immediately begins to carry out the control described in the table
shown below.
TABLE OF SELF-CONTROL TYPE GLOW PLUG OPERATION
Operating item Engine coolant temperature
Below approximately 60°C Above approximately 60°C
Glow indicator lamp control Illuminated Absence
Preheating control Presence Absence
Preheating control at start Presence Presence
Afterglow control Presence Absence
PREHEATING CONTROL
The ignition switch is turned to the "ON" position
to turn on the glow plug relay. The battery voltage
is applied to the glow plug and the glow plug
temperature increases to the starting
temperature. The period of the current flowing
through the relay is set according to the engine
coolant temperature.
PREHEATING CONTROL AT
START
The glow plug relay is turned to the "ON" position to
keep the glow plug temperature high during the engine
cranking. This also allows the good cold start
performance to be secured.
AFTERGLOW CONTROL
The glow plug relay continues to be turned to the "ON"
position for the specified period after starting the
engine. The glow plug temperature is kept high to
reduce the engine smoke and vibration after starting. If
the engine coolant temperature is high: at
approximately 60°C or more, the afterglow control is
not carried out. Therefore, if the engine coolant
temperature increases to approximately 60°C or more
after starting, the afterglow control is finished.
GLOW INDICATOR LAMP
CONTROL
The period of the glow indicator lamp illuminated
is preset according to the engine coolant
temperature at the start. If the engine coolant
temperature is high: at approximately 60°C or
more, the glow indicator lamp is not illuminated.
