Indicators; Cluster Illumination; Chime Service - Jeep Wrangler 2001 Service Manual

TJ
INSTRUMENT CLUSTER (Continued)
information for additional details on these VFD func-
tions.
The VFD is diagnosed using the EMIC self-diag-
nostic actuator test. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER
TESTING). Proper testing of the PCI data bus and
the data bus message inputs to the EMIC that con-
trol some of the VFD functions requires the use of a
DRBIII scan tool. Refer to the appropriate diagnos-
tic information. Specific operation details for the
odometer and trip odometer functions of the VFD
may be found elsewhere in this service information.

INDICATORS

Indicators are located in various positions within
the EMIC and are all connected to the EMIC elec-
tronic circuit board. The antilock brake system indi-
cator, four-wheel drive indicators, headlamp high
beam indicator, front/rear fog lamp indicator, and
turn signal indicators are hard wired. The brake
indicator is controlled by the hard wired park brake/
brake warning indicator switch input to the EMIC
and the EMIC programming. The seatbelt indicator
is controlled by the hard wired seat belt switch input
to the EMIC and the EMIC programming. The Mal-
function Indicator Lamp (MIL) is normally controlled
by PCI data bus messages from the Powertrain Con-
trol Module (PCM); however, if the EMIC loses PCI
data bus communications, the EMIC circuitry will
automatically turn the MIL on and display the mes-
sage "no BuS" in the odometer VFD until PCI data
bus communication is restored. The EMIC uses PCI
data bus messages from the PCM, Airbag Control
Module (ACM), and the Sentry Key Immobilizer
Module (SKIM) to control all of the remaining indi-
cators. Different indicators are controlled by different
strategies; some receive fused ignition switch output
from the EMIC circuitry and have a switched ground,
while others are grounded through the EMIC cir-
cuitry and have a switched battery feed.
In addition, certain indicators in this instrument
cluster are configurable. This feature allows these
indicators to be automatically enabled or disabled by
the EMIC circuitry for compatibility with certain
optional equipment. The airbag indicator, cruise indi-
cator, and the Sentry Key Immobilizer System (SKIS)
indicator are automatically configured. Once a config-
urable indicator is enabled by the EMIC, it is learned
and stored in cluster memory for the remainder of
the cluster life.
The hard wired indicators are diagnosed using con-
ventional diagnostic methods. The EMIC and PCI
bus message controlled indicators are diagnosed
using the EMIC self-diagnostic actuator test. (Refer
to 8 - ELECTRICAL/INSTRUMENT CLUSTER -
DIAGNOSIS AND TESTING). Proper testing of the
2001 JEEP WRANGLER
- DIAGNOSIS AND
INSTRUMENT CLUSTER
PCI data bus and the data bus message inputs to the
EMIC that control each indicator requires the use of
a DRBIII scan tool. Refer to the appropriate diag-
nostic information. Specific operation details for each
indicator may be found elsewhere in this service
information.

CLUSTER ILLUMINATION

The EMIC has several illumination lamps that are
illuminated when the exterior lighting is turned on
with the headlamp switch circuitry of the left multi-
function switch. The illumination brightness of these
lamps is adjusted by the panel lamps dimmer rheo-
stat when the control ring on the left multi-function
switch control stalk is rotated (downward to dim,
upward to brighten). An analog/digital (A/D) con-
verter in the EMIC converts the analog panel lamps
dimmer rheostat input from the left multi-function
switch to a digital dimming level pulse-width modu-
lated signal for controlling the lighting levels of the
EMIC VFD and cluster illumination lamps. The
EMIC also controls and synchronizes the radio and
other instrument panel lighting levels through a
hard wired panel lamp feed output circuit.
The hard wired cluster illumination inputs and
outputs are diagnosed using conventional diagnostic
methods. Proper testing of the VFD dimming level
and the EMIC A/D converter function require the use
of a DRBIII scan tool. Refer to the appropriate diag-
nostic information.

CHIME SERVICE

The EMIC is equipped with hardware and software
to provide chime service for all available features in
the chime warning system. Upon receiving the proper
chime inputs, the EMIC activates an integral chime
tone generator to provide the audible chime tone to
the vehicle operator. The chime tone generator in the
EMIC is capable of producing single chime tones or
repeated chime tones at two different rates: a slow
rate of about fifty chime tones per minute, and a fast
rate of about 180 chime tones per minute. The inter-
nal programming of the EMIC determines the prior-
ity of each chime tone request input that is received,
as well as the rate and duration of each chime tone
that is to be generated.
The EMIC relies upon hard wired inputs from the
door ajar switches, the left multi-function switch, the
ignition switch, and the park brake/brake warning
indicator switches to provide chime service for the
driver/passenger door ajar warning, the head/park
lights-on reminder, and the key-in ignition reminder.
For the remaining chime warning functions the
EMIC uses a combination of hard wired inputs, elec-
tronic message inputs received from other modules
over the PCI data bus, and internal programming.
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