Installation Manual

Electrical & Electronic Application And Installation Manual
Production Release Version 1.0
Page 42
4.5 DEF System Power Supply
Both the 1204F and 1206F aftertreatment DEF system require permanent
battery + connections in order for the controllers to remain electrically active
after the ignition signal to the engine ECM has been turned off. It is important
that when installed into a machine the control system maintains direct battery
connection to these components in order for the following shutdown /
housekeeping processes to run;
• DEF system cool down (DES if activated)
• DEF system fluid Purge
• Self-diagnosis and calibration
Once these processes are completed (may not be required for all engines and
in all circumstances) the controllers will power down.
4.5.1 1204F DEF System Power Supply connection
The Main power supply connection for the 1204F DEF system and associated
components is shown below in figure 4.7
Figure 4.7 1204F DEF System Electrical Power Supply Wiring
The main battery supply connection to the DEF system controller must be
controlled via a XNOx power relay. The operation of the relay coil is
controlled by the engine ECM allowing the engine ECM to control when the
DEF system DCU is active.
Note: The engine ECM may activate the XNOx relay for up to 20 minutes
for the ‘DPF’ product and 10 minutes for the ‘no DPF’ product after the
engine has shutdown. These are worst case values after a hot
shutdown event; normal shutdown will be closer to 4 minutes. During
this time Un-switched battery + and negative connections must be
supplied to the XNOx relay and the DCU respectively.