Ford Electric Ranger 2001 Manual page 205

211-05-3 Steering Column Switches 211-05-3
DESCRIPTION AND OPERATION (Continued)
Auxiliary Bus Operation
After a key transition from OFF to RUN, the IAA
module will wake up and request authority to use
the high-voltage auxiliary bus from the battery
control module (BCM). If the BCM grants the
authority, the IAA module will request the auxiliary
bus to close. The contactor box will close the
negative main contactor and the auxiliary precharge
contactor, thus allowing charge to flow from the
traction battery to the direct current to direct current
(DC/DC) converter, A/C inverter motor controller
(IMC), power steering module, and the positive
temperature coefficient (PTC) switching module,
thereby charging their internal bus capacitors. When
the voltage differential between the traction battery
and the auxiliary bus is below 20 volts, the
contactor box closes the auxiliary bus contactor and
signals to the IAA module the completion of this
operation. At this time, the IAA module will enable
the DC/DC converter, power steering system, and if
commanded, the climate control system. When the
key is switched back to OFF , the auxiliary bus
contactor is opened. If the vehicle is being charged,
the IAA module may close the auxiliary contactor
in order to operate the DC/DC converter. If this
happens, the contactor will be closed for 10 minutes
per cycle.
2001 Ranger EV, 01/2001