MODULE-GLOW PLUG
DESCRIPTION
CAUTION: The glow plug system is a 7 volt sys-
tem. DO NOT ATTEMPT to test the glow plug sys-
tem with a 12V power source or damage will
occur.
The glow plug module (2) is mounted to the inner
fender between the battery and the master cylinder (1)
in the engine compartment. For an explanation of the
glow plug system operation (Refer to 8 - ELECTRI-
CAL/IGNITION CONTROL/GLOW PLUG RELAY -
OPERATION).
OPERATION
CAUTION: The glow plug system is a 7 volt sys-
tem. DO NOT ATTEMPT to test the glow plug sys-
tem with a 12V power source or damage will
occur.
When the ignition (key) switch is placed in the ON
position, a signal is sent from the sensors to the ECM
relaying current engine coolant temperature and ambi-
ent air temperature.
After receiving this signal, the ECM will determine if,
when and for how long of a period the glow plugs
should be activated. This is done before, during and
after the engine is started. Whenever the glow plug
module (2) is activated, it will control the 7 volt high
amperage circuit for the operation of the four glow
plugs.
The Glow Plug lamp is tied to this circuit. Lamp oper-
ation is also controlled by the ECM.
With a cold engine, the glow plug module and glow plugs may be activated for a maximum time of 200 seconds.
Refer to the following Glow Plug Control chart for a temperature/time comparison of the glow plug relay operation.
In this chart, Pre-Heat and Post-Heat times are mentioned. Pre-Heat is the amount of time the glow plug control
circuit is activated when the ignition (key) is switched ON, without the engine running. Post-Heat is the amount of
time the glow plug control circuit is activated after the engine is operated. The Glow Plug lamp will not be activated
during the post-heat cycle.
8I - 24
IGNITION CONTROL
KJ