Installation Manual

Electrical & Electronic Application And Installation Manual
Production Release Version 1.0
Page 160
12.1 Control of Glow Plugs by the Engine ECM
12.1.1 Glow Plug System Operation
Glow plugs are fitted as standard to all Tier 4 Final/Stage IV engines.
When the ignition keyswitch is on, the engine ECM will monitor the coolant
temperature and the inlet air temperature and decide whether the glow plugs
are required. If so, the ECM will activate the glow plug relay and supply
current to the engine glow plugs.
On a cold start when the ECM decides that it is necessary for the glow plugs
to be activated prior to starting, a lamp output will indicate to the operator that
they need to ‘wait to start’. Note that it is possible that the start aids will also
be used either during cranking or when the engine has started. Under these
conditions however the lamp will not be active. The control strategy for start
aid control is shown in figure 12.2