data bus. The FCM responds to these messages by controlling a battery voltage output and the flash rate for either
the right or left turn signal lamps. The FCM also sends the appropriate electronic messages back to the EMIC to
control the illumination and flash rate of the right or left turn signal indicators, as well as to control the click rate of
an electromechanical relay soldered onto the EMIC electronic circuit board that emulates the sound emitted by a
conventional turn signal flasher.
The EMIC also provides a “turn signal on warning” that will generate repetitive chimes to indicate that a turn signal
has been active continuously for 1.6 kilometers (1 mile) with the vehicle speed greater than 22 kilometers-per-hour
(15 miles-per hour). Vehicles built for markets other than the United States and Canada have a revised distance
threshold of 4 kilometers for this feature. The chime will continue until the turn signal input becomes inactive or until
the vehicle speed message indicates that the speed is less than 22 kilometers-per-hour (15 miles-per-hour), which-
ever occurs first.
WARNING
WARNINGS - LAMPS/LIGHTING - EXTERIOR
WARNING:: To avoid personal injury or death, eye protection should be used when servicing any glass
components.
CAUTION: Do not contaminate the glass of halogen bulbs with fingerprints or allow contact with other pos-
sibly oily surfaces. Reduced bulb life will result.
CAUTION: Do not use bulbs with higher candle power than indicated in the Bulb Application table (Refer to
8 - ELECTRICAL/LAMPS/LIGHTING - EXTERIOR - SPECIFICATIONS). In addition, do not use fuses, circuit
breakers or relays having greater amperage value than indicated on the fuse panel or in the Owner’s Man-
ual. Damage to lamps, lenses, wiring and other related electrical components can result.
DIAGNOSIS AND TESTING
LAMPS/LIGHTING - EXTERIOR
WARNING: To avoid personal injury or death, on vehicles equipped with airbags, disable the supplemental
restraint system before attempting any steering wheel, steering column, airbag, occupant classification sys-
tem, seat belt tensioner, impact sensor, or instrument panel component diagnosis or service. Disconnect
and isolate the battery negative (ground) cable, then wait two minutes for the system capacitor to discharge
before performing further diagnosis or service. This is the only sure way to disable the supplemental
restraint system. Failure to take the proper precautions could result in accidental airbag deployment.
NOTE: When diagnosing the exterior lighting circuits, remember that high generator output can burn out
bulbs rapidly and repeatedly; and, that dim or flickering bulbs can be caused by low generator output or
poor battery condition. If one of these symptoms is a problem on the vehicle, be certain to diagnose the
battery and charging system, then repair as necessary.
NOTE: A good ground is necessary for proper lighting operation. If a lighting problem is being diagnosed
that involves multiple symptoms, systems, or components, the problem can often be traced to a loose, cor-
roded, or open ground.
The hard wired exterior lamp and lighting circuits may be diagnosed and tested using conventional diagnostic tools
and procedures. 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.
However, conventional diagnostic methods may not prove conclusive in the diagnosis of the ElectroMechanical
Instrument Cluster (EMIC), the Front Control Module (FCM), the Integrated Power Module (IPM), the Power Distri-
bution Center (PDC), the Powertrain Control Module (PCM), the Controller Area Network (CAN) data bus, or the
electronic message inputs used to provide exterior lamp and lighting service or many of the electronic features of
the exterior lamp and lighting systems. The most reliable, efficient, and accurate means to diagnose the EMIC, the
8L - 82
LAMPS/LIGHTING - EXTERIOR - SERVICE INFORMATION
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