Concorde V6-2.7L VIN V (2001)
Body Control Module: Description and Operation
Part 3 of 5
Part 3A
INTERIOR LIGHTING
Courtesy Lamp Control
The body controller has direct control over the majority of the vehicle's courtesy lamps. The body computer will illuminate the courtesy lamps
under any of the following conditions:
1. Any door is ajar.
2. The courtesy lamp switch on the instrument panel is closed.
3. A Remote Keyless entry unlock message is received. If the interior lamps are left ON after the ignition is turned OFF, the BCM will turn them
OFF after 1 hour or until either the dome lamp switch or door ajar switch changes state.
Illuminated Entry
Illuminated entry will be initiated when the customer enters the vehicle by unlocking the doors with the key fob, or with the key if the vehicle is
equipped with vehicle theft alarm. Upon exiting the vehicle, if the lock button is pressed with a door open, illuminated entry will cancel when the
door closes. If the doors are closed and the ignition switch is turned ON, the illuminated entry also cancels.
MECHANICAL INSTRUMENT CLUSTER
The instrument cluster displays four gauges, a Vacuum Fluorescent (VF) odometer, a VF PRNDL and up to (18) indicators. One reset button is
used to switch the display from trip to total. Holding the button when the display is in the trip mode will reset the trip mileage. The cluster also
supplies the power for the panel illumination. Most of the information that is displayed is received over the PCI bus from several modules.
With ignition in "lock", the cluster will wake up and display the door ajar and odometer display when a door is opened. The cluster will also wake
up to control the panel illumination. In "OFF' (unlock) the PRNDL and several indicators will be functional but all gauges will not function. On
transition from "OFF" (unlock) to run, the cluster will perform a check of all micro-controlled indicators, the odometer and the PRNDL for
approx. 2 seconds. Other bulb checks with longer bulb check duration will be performed based on bus messages from other modules. If the cluster
receives no PCI bus messages for (20) seconds after the transition to "run", the cluster will display "no bus" in the odometer.
A self test can be initiated by holding down the odometer reset button and switching the ignition from "lock" to "OFF" (unlock). This test will
activate the gauges, turn ON the indicator lights along with the odometer and PRNDL segments.
MEMORY SYSTEM
The memory system consists of power left front seat, power mirrors and radio presets. The memory heated seat/mirror module (MHSMM) also
includes the heated seat function. The module is located under the left front seat and receives input from: left manual 8-way seat switch, left seat
position sensors, memory switch, both heated seat switches, both heated seat negative temperature coefficients (NTC's) thermistors), PCI bus
circuits, and the power mirror sensors. The module uses these in- puts to perform the following functions: position the drivers memory seat, both
exterior mirrors, actuate the drivers and passenger heated seat heater and send the memory location over the PCI bus.
When a memory button is pressed (either # 1 or # 2) on the memory switch the MHSMM sends a message to the BCM which in turn sends a recall
message to the MHSMM and the PCI radio. They will in turn position the drivers seat and both mirrors along with setting the radio presets. If the
drivers seat or either exterior mirrors are inoperative from their own respected switches, use the service information and schematic to diagnose the
problem. This addresses the memory problems only and it is assumed there is not a basic component failure.
Power Seat
The memory power seat provides the driver with 2 position settings for the left seat. Each power seat motor is connected to the MHSMM with two
circuits. Each circuit is switched between battery and ground. By alternating the circuits the MHSMM controls the movement of the motors based
on input from the power seat switch or through memory recall.
Each motor contains a potentiometer to monitor the seat position. To monitor the position of the motor, the MHSMM sends out a 5-volt reference
on the sensor supply circuit. The sensor is grounded back to the module on a common ground circuit. Based on the position of the sensor, the
MHSMM monitors the voltage change through the sensor on a separate signal circuit.
The MHSMM stores the input value of each of the four seat potentiometers in memory when the system is requested. The driver can initiate
memory recall, using either the seat mounted memory switch or the RKE transmitter. When initiated, the MHSMM adjusts the four seat motors to
match the memorized seat position data.
For safety, the memory seat recall is disabled by the MHSMM when the vehicle is out of park position. Any obstruction to seat movement over a 2
second delay will cause the seat to stop moving in which case a stalled motor would be detected by the MHSMM which would then flag a trouble
code and the corresponding seat output would be deactivated. However, if the object obstructing the seat is removed, the seat will function
normally again.
Memory Seat Glide
