Chime System - Chrysler Concorde 2004 Service Manual

GENERAL INFORMATION

3.4 CHIME SYSTEM

The chime system is comprised of an audible
chime located internal to the BCM; and is depen-
dent on various inputs to the BCM to operate. These
inputs include key-in ignition switch, exterior
lamps, seat belt switch, and requests from the MIC
to chime when some indicators are turned on.
3.5 DOOR AJAR SYSTEM
The door ajar state is used as an input for various
control modules on the vehicle. The DRBIII will
display the state of the door ajar switches in Inputs/
Outputs. It's important to note, that when a door is
closed, the switch state on the DRBIII will show
OPEN, and when the door is open, the switch state
will show CLOSED. During diagnosis, if a door is
closed and the DRBIII displays the switch state as
CLOSED, it indicates a shorted door ajar circuit. If
the door is open and the DRBIII
switch state as OPEN, it indicates an open door ajar
circuit.
3.6 CLIMATE CONTROL SYSTEMS
3.6.1 AUTOMATIC TEMPERATURE
CONTROL (ATC)
The body control module (BCM) provides auto-
matic temperature control support both through
PCI bus communications and through processing
inputs to determine control for actuators and the
blower motor. The BCM interfaces with the ATC
control head over the PCI bus. Information on
button activation, blower setting, and temperature
setting are supplied to the BCM. In turn, the BCM
supplies the ATC control head with mode informa-
tion and indication lamp status. The BCM controls
blower motor speed by providing a varying duty
cycle of a fixed frequency output (pulse width mod-
ulation). There are 14 distinct blower speeds, plus a
blower off signal. The body control module also
controls the HVAC mode, temperature (blend air),
and recirculation doors. This system is either fully
automatic or fully manual control (no semi-
automatic functions); however, the temperature
blend door control is always automatically con-
trolled based on sensor reading and comfort setting.
The in-car sensor and the aspirator motor are now
housed in the ATC control head.
3.6.2 MANUAL TEMPERATURE CONTROL
The body control module interfaces with the a/c-
heater control head via hardwired circuits. Infor-
mation for the temperature setting is supplied to
the body control module via a potentiometer. The
rear defogger switch, A/C switch and the mode
setting is supplied via a resistive multiplexed cir-
cuit. The system on/off status is supplied by a
dedicated circuit. The BCM drives the A/C and rear
defogger indicator lamps via hardwire to the A/C-
heater control head.
3.6.3 HVAC BLEND, MODE, AND
The trouble codes that indicate a stall failure or a
feedback signal failure work together to show what
is wrong with the HVAC system. The stall trouble
codes mean that the body control module cannot
force an actuator to the end of the HVAC unit door.
Internal problems in the body control module will
set other short-related codes. Having only stall
trouble codes indicates that there is a problem with
an open or short circuit in the wiring, a bad actua-
tor, a bad HVAC unit door or connecting linkage. It
is important that the operation of the HVAC door be
displays the
checked if an actuator is removed. This can be
checked by rotating each unit door shaft to confirm
that the door will stop at both ends of travel. The
actuator itself has no stops. It must have the HVAC
unit door to stop travel to pass a stall test.
A feedback signal failure can occur on the blend
or mode door. The body control module monitors the
feedback signal to check the position of the actuator.
The body control module not only checks the level of
the signal but also how much the voltage changes.
A feedback failure can occur if there is a short or
open circuit in the wiring, a bad actuator, a bad
body control module, a bad HVAC unit door or
connecting linkage. The easiest way to diagnose
this is to use the DRB to actuate the blend or mode
door. Note that the feedback voltage of the actuator
should smoothly change as the actuator is moved. A
sudden change in the feedback voltage to a 5.0-volt
or a 0.0-volt level indicates the actuator is bad. A
fixed feedback voltage that is less than 5.0 volts or
greater than 0.0 volts without a stall failure, or a
short failure indicates that the actuator, the HVAC
unit door, or a connecting mechanical linkage is
jammed thereby preventing movement. A feedback
signal voltage that stays on 5.0 volts or 0.0 volts
indicates a wiring or body control module problem.
The feedback voltage should always be less than 5.0
volts and greater than 0.0 volts.
The feedback trouble code can also occur from
lack of actuator travel. This can be checked by
confirming that the feedback signal smoothly
changes when the actuator is moved with the DRB.
If the signal is OK, the door travel is not correct.
The actuator must be removed and the HVAC unit
door mechanically checked for proper operation.
Typical problems that prevent door movement in-
8
RECIRCULATION DOOR OPERATION