Grand Caravan V6-3.3L VIN R (2005)
noticeable by observing the operation of the radio or blower functions.
Horn relay
The horn relay operates through a direct wire input to the FCM from the horn switch (FCM pin 17) , or a PCI Bus message from the BCM. The relay
responds to the horn switch, remote door lock and VTA alarm functions. The horn relay is powered through low side control on pin 10 of the FCM.
Under normal operating conditions, if the horn is pressed for longer than 30 seconds, the FCM will automatically deactivate the horn to prevent damage
to it. The FCM will re-activate control of the relay after a 25 second cool-down period. This circuit is electronically controlled and continuously
monitored for malfunctions.
Front and rear blower relay
RS with MTC
Upon ignition on, the A/C-Heater Control Module sends a blower relay on request to the FCM over the PCI Bus.The front blower relay and the rear
blower relay, if equipped, are then powered through low side control through FCM pin 30. The relay provides the high side to the blower motor, and the
blower speed is governed through low side control in the A/C-Heater Control Module. This circuit is electronically controlled and continuously
monitored for malfunctions.
RG with MTC
Upon power up (Power switch on), the A/C-Heater Control Module sends a blower relay on request to the FCM over the PCI Bus. The front blower
relay is then powered through low side control through FCM pin 30. The relay provides the high side to the blower motor, and the blower speed is
governed through low side control in the A/C-Heater Control Module. This circuit is electronically controlled and continuously monitored for
malfunctions.
Name Brand Speakers (NBS) relay
The NBS relay operates through the vehicle bus interface between the radio and the FCM. When the radio is turned on, the radio sends a PCI Bus
message to the FCM. The NBS relay is then powered on through low side control on pin 11 of the FCM. The relay supplies power to the amplified
speaker, and ground is supplied through the radio. This circuit is electronically controlled and continuously monitored for malfunctions.
Electronic Back Light (EBL) relay
The rear defrost switch is part of the Automatic Temperature Control or A/C-Heater Control Module (Manual Temp). When the ignition switch is in the
RUN position and the rear defrost switch is turned on, the ATC or A/C-Heater Control Module sends a PCI Bus message to the FCM. The EBL run only
relay is then powered through low side control on pin 31 of the FCM. The relay provides the high side to the rear window defrost grid, and ground is
attached to the vehicle body. The FCM will only allow the rear defrost to operate in the RUN position. This circuit is electronically controlled and
continuously monitored for malfunctions.
Adjustable Pedals Relay (Non-Memory)
The Adjustable Pedals Relay is only on nonmemory Adjustable Pedals System equipped vehicles. The relay is supplied battery voltage from the IPM and
is electronically controlled with a low side driver within the FCM. The relay is energized when the transmission is in reverse and when cruise control
operation is engaged. This action disables the Adjustable Pedals System from movement. This circuit is continuously monitored for proper function.
ELECTRICAL INPUTS
Headlamp battery supplies 1 & 2 - 12 volt input on pins 1 and 2. Battery supply voltage for switching headlamp circuits only.
Module battery supply - 12 volt input on pin 9. Battery supply voltage for all other FCM operations.
Power ground - Ground source on pin 8 for all FCM operations.
Ignition switch RUN or START position status - 12 volt input on pin 37. Allows the FCM to determine the ignition switch status for related FCM
operations.
PCI Bus - Approximately 7.5 volt input on pin 22. Allows the FCM to communicate with other modules on the vehicle bus.
Stop lamp Switch status - 12 volt input on pin 44. Provides for brake shift interlock function.
Horn Switch - Ground input on pin 17. Primary means for engaging the horn.
Back-up switch - Ground input on pin 39. Input is converted to a PCI Bus status message for use by other modules.
Wiper park switch - Ground input on pin 16. Used to determine park placement of wipers. Also used as feedback to FCM to determine correct
operating mode of wipers.
