for illuminating and indicating purposes. Lighting
circuits are protected by fuses. Lighting circuits
require an overload protected power source, on/off
device, lamps and body ground to operate properly.
Replace sockets and bulbs that are corroded.

Wire connectors can make intermittent contact or

become corroded. Before coupling wire connectors,
inspect the terminals inside the connector. Male termi-
nals should not be bent or disengaged from the insu-
lator. Female terminals should not be sprung open or
disengaged from the insulator. Bent and sprung termi-
nals can be repaired using needle nose pliers and pick
tool. Corroded terminals appear chalky or green. Cor-
roded terminals should be replaced to avoid recur-
rence of the problem symptoms.

Begin electrical system failure diagnosis by testing

related fuses in the Junction Block (JB) and the
Power Distribution Center (PDC). Verify that bulbs
are in good condition and test continuity of the cir-
cuit ground. Refer to the appropriate wiring informa-
tion.

The

wiring

information

includes

wiring

diagrams, proper wire and connector repair proce-
dures, details of wire harness routing and retention,
connector pin-out information and location views for
the various wire harness connectors, splices and
grounds.

DESCRIPTION - TURN SIGNAL & HAZARD
WARNING SYSTEM

A turn signal and hazard warning system is stan-

dard

factory-installed

safety

equipment

this

model. The turn signal and hazard warning system
includes the following major components, which are
described in further detail elsewhere in this service
information:

• Combination Flasher - The electronic combi-

nation flasher is installed in a dedicated connector of
the instrument panel wire harness located under the
instrument panel outboard of the steering column
opening.

• Hazard Warning Switch - The hazard warning

switch is integral to the multi-function switch on the
left side of the steering column. The hazard warning
switch button protrudes from a dedicated opening in
the shroud on the top of the steering column, just
below the steering wheel.

• Turn Signal Cancel Cam - The turn signal

cancel cam is integral to the clockspring, which is
located beneath the steering column shrouds at the
top of the steering column, just below the steering
wheel.

• Turn Signal Indicators - The two turn signal

indicators, one right and one left, are integral to the
ElectroMechanical

Instrument

Cluster

(EMIC)

located in the instrument panel.

• Turn Signal Lamps - The front turn signal

lamps are integral to the lower front outboard ends
of the headlamp modules, located just outboard of the
two sides of the radiator grille opening. The rear
turn signal lamps are integral to the taillamp mod-
ules that are secured to the quarter panels at each
side of the tailgate opening.

• Turn Signal Switch - The turn signal switch is

integral to the multi-function switch on the left side
of the steering column. The multi-function switch
control stalk that actuates the turn signal switch
protrudes from a dedicated opening in the steering
column shrouds on the left side of the column, just
below the steering wheel.

The turn signal system in this vehicle includes a

turn signal warning chime feature. The EMIC moni-
tors the turn signal indicators and sends an elec-
tronic chime request message to the Central Timer
Module (CTM) over the Programmable Communica-
tions Interface (PCI) data bus network if the indica-
tor remains illuminated with the vehicle speed above
about 25 kilometers per hour (15 miles per hour) for
a distance of greater than about 1.6 kilometers (1
mile). (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DESCRIPTION).

Hard wired circuitry connects the turn signal and

hazard warning system components to each other
through the electrical system of the vehicle. These
hard wired circuits are integral to several wire har-
nesses, which are routed throughout the vehicle and
retained by many different methods. These circuits
may be connected to each other, to the vehicle elec-
trical system and to the turn signal and hazard
warning system components through the use of a
combination of soldered splices, splice block connec-
tors and many different types of wire harness termi-
nal

connectors

and

insulators.

Refer

the

appropriate wiring information. The wiring informa-
tion includes wiring diagrams, proper wire and con-

8L - 2

LAMPS/LIGHTING - EXTERIOR

nector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds.

OPERATION - EXTERIOR LAMPS

The headlamps operate through the headlamp

switch which provides a ground signal to the head-
lamp beam selector in the multi-function switch. The
multi-function switch sends a low or high beam sig-
nal input to the Central Timer Module (CTM), which
provides current to the headlamps accordingly.

For park lamps operation the headlamp switch

provides a ground signal to the Central Timer Mod-
ule (CTM), which energizes the park lamp relay.
Once the park lamp relay is energized, current is
provided to the park lamps through fuse 4 in the
junction block.

For fog lamps operation the headlamp switch pro-

vides a ground signal to the Central Timer Module
(CTM) which energizes the fog lamp relay. Once the
fog lamp relay is energized, current is provided to the
fog lamps through fuse H in the Power Distribution
Center (PDC).

OPERATION - TURN SIGNAL & HAZARD
WARNING SYSTEM

The turn signal system operates on battery current

received on a fused ignition switch output (run-acc)
circuit so that the turn signals will only operate with
the ignition switch in the On or Accessory positions.
The

hazard

warning

system

operates

non-

switched battery current received on a fused B(+) cir-
cuit so that the hazard warning remains operational
regardless of the ignition switch position. When the
turn signal (multi-function) switch control stalk is
moved up (right turn) or down (left turn), the turn
signal system is activated. When the turn signal sys-
tem is activated, the circuitry of the turn signal
switch and the combination flasher will cause the
selected (right or left) turn signal indicator, front
park/turn signal lamp, and rear tail/stop/turn signal
lamp to flash on and off. With the hazard warning
(multi-function) switch in the On position, the hazard
warning system is activated. When the hazard warn-
ing system is activated, the circuitry of the hazard
warning switch and the combination flasher will
cause both the right side and the left side turn signal
indicators, front park/turn signal lamps, and rear
tail/stop/turn signal lamps to flash on and off.

In order to provide the turn signal on warning, the

ElectroMechanical Instrument Cluster (EMIC) moni-
tors vehicle speed and distance messages received
from the Powertrain Control Module (PCM) over the
Programmable Communications Interface (PCI) data
bus and the hard wired turn signal switch input to

the cluster electronic circuit board. If a turn signal
remains indicated for a distance of greater than
about 1.6 kilometers (1 mile) and the vehicle speed
remains greater than about 24 kilometers-per-hour
(15 miles-per-hour), the EMIC generates an elec-
tronic chime request message to the Central Timer
Module (CTM) over the PCI data bus. The CTM then
generates an audible chime tone through its integral
chime tone generator to provide an audible reminder
that a turn signal has been left on. Once the warning
chime begins to sound, it will continue until the turn
signal is cancelled (either manually or mechanically),
until the vehicle speed falls below about 24 kilome-
ters-per-hour (15 miles-per-hour), or until the igni-
tion switch is turned to the Off position, whichever
occurs first.

The hard wired circuits of the turn signal and haz-

ard warning system can be diagnosed using conven-
tional diagnostic tools and methods; however, for
proper diagnosis of the turn signal on warning fea-
ture, the EMIC, the CTM, and the PCI data bus
must be tested using a DRBIII

t scan tool. Refer to

the appropriate diagnostic information. Refer to the
owner’s manual in the vehicle glove box for more
information on the features, use and operation of the
turn signal and hazard warning system.

WARNING - SAFETY PRECAUTIONS

WARNING: EYE PROTECTION SHOULD BE USED
WHEN SERVICING GLASS COMPONENTS. PER-
SONAL INJURY CAN RESULT.

CAUTION:
Do not touch the glass of halogen bulbs with fin-
gers or other possibly oily surface, reduced bulb
life will result.
Do not use bulbs with higher candle power than
indicated in the Bulb Application table at the end of
this group. Damage to lamp and/or Daytime Run-
ning Lamp Module can result.
Do not use fuses, circuit breakers or relays having
greater amperage value than indicated on the fuse
panel or in the Owners Manual.

NOTE: When it is necessary to remove components
to service another, it should not be necessary to
apply excessive force or bend a component to
remove it. Before damaging a trim component, ver-
ify hidden fasteners or captured edges are not hold-
ing the component in place.

LAMPS/LIGHTING - EXTERIOR

8L - 3

LAMPS/LIGHTING - EXTERIOR (Continued)

Content .. 326 327 328 329 ..