Chrysler 300M 1999, Manual, Page: 15 / 766

The minimum time shown for any code will be one minute, even if the code was actually present
for less than one minute. Thus, the time shown for a code that was present for two minutes 13
seconds, for example, would be three minutes.
If a malfunction is detected a diagnostic trouble code is stored and will remain stored as long as
the malfunction exists. When and if the malfunction ceases to exist, an ignition cycle count will be
initiated for that code. If the ignition cycle count reaches 100 without a reoccurrence of the same
malfunction, the diagnostic trouble code is erased and that ignition cycle counter is reset to zero.
If the malfunction reoccurs before the count reaches 100, then the ignition cycle counter will be
reset and the diagnostic trouble code will continue to be a stored code.
If a malfunction is not active while performing a diagnostic test procedure, the active code
diagnostic test will not locate the source of the problem. In this case, the stored code can indicate
an area to inspect.
If no obvious problems are found, erase stored codes, and with the ignition
9
on
9
wiggle the wire
harness and connectors, rotate the steering wheel from stop to stop. Recheck for codes
periodically as you work through the system. This procedure may uncover a malfunction that is
difficult to locate.
3.2 Audio System
There are three radio systems available that communicate on the PCI bus. They are RBR, RBN,
and RAZ models. They use the bus for two reasons. First is to communicate trouble codes to the
body control module, the second is for use with the driver memory selection system. The radio
stores two sets of station presets and can be recalled by pressing the optional memory select
button (located on the drivers door). The RBR will have 6 speakers and a 120 watt external
amplifier. The RBN will have 7 speakers and a 240 watt external amplifier. The RAZ will have 9
speakers and a 320 watt external amplifier. Depending on the manufacturer, some systems have
a Front/Rear channel system and others have a Left/Right channel system.
3.3 Auto Headlamps
The headlamps and park/tail lamps will be activated by the BCM when the headlamp switch is in
the auto mode. To activate the auto headlamps the BCM requires that: (1) the headlamp switch
is in the ‘‘A’’ position, (2) the engine is running, and (3) the light level sensed through the sun load
sensor falls below the calibrated level.
3.4 Body Control Module
The body control module (BCM) supplies vehicle occupants with visual and audible information
and controls various vehicle functions. To provide and receive information, the module is
interfaced to the vehicle’s serial bus communications network (the Programmable Communica-
tion Interface or PCI bus). This network consists of the powertrain control module (PCM), the
memory heat seat/mirror module (MHSMM), sentry key immobilizer module (SKIM), the trans-
mission control module (TCM), the electro/mechanical instrument cluster (MIC), the radio, the
optional overhead travel information system (OTIS), airbag control module (ACM), optional
antilock brakes (ABS) and the optional automatic temperature control (ATC) display head. The
BCM is operational when battery power is supplied to the module, ignition switch power is needed
for ignition switched functions.
The body control module provides the following features:
Automatic headlamp and foglamp
A/C switch status / evaporator temperature status
BCM diagnostic support
Central lock and unlock (VTSS only)
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