Chrysler 300M Service Manual page 240

LH
REAR WINDOW ANTENNA MODULE (Continued)
REMOVAL
(1) Open hood and disconnect the negative battery
cable remote terminal from the remote battery post.
(2) Remove right upper quarter trim panel. (Refer
to 23 - BODY/INTERIOR/UPPER QUARTER TRIM -
REMOVAL).
(3) Remove the attaching screw from module.
(4) Disconnect wire connectors and radio antenna
coaxial cable (Fig. 8).
(5) Remove module from vehicle.
INSTALLATION
(1) Install module from vehicle.
(2) Connect wire connectors and radio antenna
coaxial cable (Fig. 8).
(3) Install the attaching screw to module.
(4) Install right upper quarter trim panel. (Refer
to 23 - BODY/INTERIOR/UPPER QUARTER TRIM -
INSTALLATION).
(5) Connect the negative battery cable remote ter-
minal to the remote battery post.
REMOTE SWITCHES
DESCRIPTION
Remote radio control switches are rocker-type
switch units (Fig. 10) are mounted in the upper
spoke covers of the rear (instrument panel side)
steering wheel trim cover. The switch unit on the left
side is the seek switch and has seek up, seek down,
and preset station advance switch functions. The
switch unit on the right side is the volume control
switch and has volume up, volume down, and mode
advance switch functions.
The two remote radio switch units are each
retained in a mounting hole located on opposite sides
of the rear steering wheel trim cover by four integral
snap features. A plastic bracket on the back of each
switch unit provides additional support for the unit
by extending towards the center of the steering
wheel where it is clamped between the steering
wheel armature and the steering wheel rear trim
cover mounting boss by the trim cover mounting
screw.
The two remote radio switch units share a common
steering wheel wire harness with the vehicle speed
control switches. The steering wheel wire harness is
connected to the instrument panel wire harness
through the clockspring.
OPERATION
The six switches in the two remote radio switch
units are normally
momentary switches that are hard wired to the Body
Control Module (BCM) through the clockspring. The
open, resistor multiplexed
Fig. 10 REMOTE RADIO SWITCHES
1 - PRESET ADVANCE
2 - SEEK
3 - MODE ADVANCE
4 - VOLUME
BCM sends a five volt reference signal to both switch
units on one circuit, and senses the status of all of
the switches by reading the voltage drop on a second
circuit.
When the BCM senses an input (voltage drop) from
any one of the remote radio switches, it sends the
proper switch status messages on the Programmable
Communication Interface (PCI) data bus network to
the radio receiver. The electronic circuitry within the
radio receiver is programmed to respond to these
remote radio switch status messages by adjusting the
radio settings as requested. For diagnosis of the
BCM or the PCI data bus, the use of a DRB III scan
tool and the proper Body Diagnostic Procedures man-
ual are recommended.
For more information on the features and control
functions for each of the remote radio switches, see
the owner's manual in the vehicle glove box.
DIAGNOSIS AND TESTING - REMOTE
SWITCHES
Any diagnosis of the Audio system should
begin with the use of the DRB III
tool. For information on the use of the DRB
III , refer to the appropriate Diagnostic Service
Manual.
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
AUDIO/VIDEO 8A - 11
diagnostic