Dodge 2000 DURANGO Service Manual page 490

8U - 2 CHIME/BUZZER WARNING SYSTEMS
DESCRIPTION AND OPERATION (Continued)
programming, and a hard-wired chime request input
from the instrument cluster circuitry to detect when
a chime tone is required.
Both versions of the CTM are mounted under the
passenger side end of the instrument panel, outboard
of the instrument panel glove box opening. Refer to
Central Timer Module in the Removal and Installa-
tion section of Group 8E - Instrument Panel Systems
for the service procedures.
This group covers the diagnosis and service of only
the hard-wired inputs used by the CTM to determine
that a chime tone should be generated. See Central
Timer Module in the Diagnosis and Testing section of
this group for diagnosis of the base version of the
CTM. For diagnosis of the high-line version of the
CTM or of the CCD data bus, a DRBIII
and the proper Diagnostic Procedures manual are
recommended. The CTM cannot be repaired and, if
faulty or damaged, it must be replaced.
INSTRUMENT CLUSTER
The instrument cluster is an electromechanical
unit that contains integrated circuitry and internal
programming to perform a variety of functions. The
instrument cluster circuitry monitors hard-wired
switch inputs, as well as message inputs received
from other vehicle electronic modules on the Chrysler
Collision Detection (CCD) data bus network.
The instrument cluster uses these many inputs
along with its internal programming to provide hard-
wired chime tone requests to the Central Timer Mod-
ule (CTM), which performs the functions of the chime
warning module on this model. The instrument clus-
ter circuitry also has a self-diagnostic capability.
Refer to Instrument Cluster in the Diagnosis and
Testing section of Group 8E - Instrument Panel Sys-
tems for more information on this feature.
The only instrument cluster diagnosis found in this
group consists of confirming the viability of the hard-
wired chime request circuit between the instrument
cluster circuitry and the CTM, and diagnosis of the
hard-wired seat belt switch input to the instrument
cluster. For diagnosis of the CCD data bus and the
data bus message inputs, a DRB scan tool and the
proper Diagnostic Procedures manual are recom-
mended.
Refer to Instrument Cluster in the Removal and
Installation section of Group 8E - Instrument Panel
Systems for the instrument cluster service proce-
dures. Refer to the Diagnosis and Testing section of
Group 8E - Instrument Panel systems for more infor-
mation on the remaining hard-wired instrument clus-
ter inputs. The instrument cluster chime warning
circuitry cannot be repaired and, if faulty or dam-
aged, the instrument cluster assembly must be
replaced.
DRIVER DOOR AJAR SWITCH
The driver door ajar switch is integral to the driver
side front door latch. The switch closes a path to
ground for the Central Timer Module (CTM) when
the driver door is opened, and opens the ground path
when the driver door is closed.
The driver door ajar switch cannot be repaired
and, if faulty or damaged, the door latch unit must
be replaced. Refer to Group 23 - Body for the door
latch service procedures.
KEY-IN IGNITION SWITCH
The key-in ignition switch is integral to the igni-
tion switch, which is mounted on the right side of the
steering column. It closes a path to ground for the
scan tool
Central Timer Module (CTM) when the ignition key
is inserted in the ignition lock cylinder and the
driver door ajar switch is closed (driver door is open).
The key-in ignition switch opens the ground path
when the key is removed from the ignition lock cyl-
inder. The ground path is also opened when the
driver door ajar switch is open (driver door is closed).
The key-in ignition switch cannot be repaired and,
if faulty or damaged, the entire ignition switch must
be replaced. Refer to Group 8D - Ignition Systems for
the service procedures.
HEADLAMP SWITCH
The headlamp switch is located in the instrument
panel, outboard of the steering column. It closes a
path to ground for the Central Timer Module (CTM)
when the park or head lamps are on and the driver
door ajar switch is closed (driver door is open). The
headlamp switch opens the ground path when the
headlamp switch is turned off. The ground path is
also opened when the driver door ajar switch is open
(driver door is closed).
The headlamp switch cannot be repaired and, if
faulty or damaged, it must be replaced. Refer to
Headlamp Switch in the Removal and Installation
section of Group 8E - Instrument Panel Systems for
the service procedures.
DRIVER SEAT BELT SWITCH
The driver seat belt switch is integral to the driver
seat belt retractor assembly. The driver seat belt
switch is normally closed, providing a ground signal
to the instrument cluster when the ignition switch is
in the On or Start positions.
The seat belt switch monitors the amount of seat
belt webbing wound onto the seat belt retractor
spool. When the seat belt tip-half webbing is pulled
out of the retractor far enough to engage the seat
belt buckle-half, the switch opens the seat belt switch
sense circuit.
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