Cruise Indicator Description - Chrysler Vehicle User Manual

8J - 24 INSTRUMENT CLUSTER
CHECK GAUGES INDICATOR (Continued)
gauge readings reflect a condition requiring immedi-
ate attention. This indicator is controlled by a tran-
sistor on the instrument cluster circuit board based
upon cluster programming and electronic messages
received by the cluster from the Powertrain Control
Module (PCM) over the Programmable Communica-
tions Interface (PCI) data bus. The check gauges
indicator Light Emitting Diode (LED) is completely
controlled by the instrument cluster logic circuit, and
that logic will only allow this indicator to operate
when the instrument cluster receives a battery cur-
rent input on the fused ignition switch output (run-
start) circuit. Therefore, the LED will always be off
when the ignition switch is in any position except On
or Start. The LED only illuminates when it is pro-
vided a path to ground by the instrument cluster
transistor. The instrument cluster will turn on the
check gauges indicator for the following reasons:
• Bulb Test - Each time the ignition switch is
turned to the On position the check gauges indicator
is illuminated for about two seconds as a bulb test.
• Engine Temperature High Message - Each
time the cluster receives a message from the PCM
indicating the engine coolant temperature is about
127° C (261° F) or higher, the check gauges indicator
will be illuminated. The indicator remains illumi-
nated until the cluster receives a message from the
PCM indicating that the engine temperature is about
124° C (255° F) or lower, or until the ignition switch
is turned to the Off position, whichever occurs first.
• Engine Oil Pressure Low Message - Each
time the cluster receives a message from the PCM
indicating the engine oil pressure of a 2.4L engine is
below about 0.2 kg/cm
than a 2.4L is below about 0.4 kg/cm
check gauges indicator will be illuminated. The indi-
cator remains illuminated until the cluster receives a
message from the PCM indicating that the engine oil
pressure of a 2.4L engine is above about 0.2 kg/cm
(3 psi), or of any engine other than a 2.4L is above
2
about 0.4 kg/cm (6 psi), or until the ignition switch
is turned to the Off position, whichever occurs first.
The cluster will only turn the indicator on in
response to an engine oil pressure low message if the
engine speed is 300 rpm or greater for more than
about five seconds.
• System Voltage Low (Charge Fail) Message
- Each time the cluster receives a message from the
PCM indicating the electrical system voltage is about
9.0 volts or lower (charge fail condition), the check
gauges indicator will be illuminated. The indicator
remains illuminated until the cluster receives a mes-
sage from the PCM indicating the electrical system
voltage is greater than about 12.0 volts (but less than
16.0 volts), or until the ignition switch is turned to
the Off position, whichever occurs first.
2
(3 psi), or of any engine other
2
(6 psi), the
• System Voltage High Message - Each time
the cluster receives a message from the PCM indicat-
ing the electrical system voltage is greater than
about 16.0 volts, the check gauges indicator will be
illuminated. The indicator remains illuminated until
the cluster receives a message from the PCM indicat-
ing the electrical system voltage is less than about
16.0 volts (but higher than 9.0 volts), or until the
ignition switch is turned to the Off position, which-
ever occurs first.
• Actuator Test - Each time the cluster is put
through the actuator test, the check gauges indicator
will be turned on, then off again during the bulb
check portion of the test in order to confirm the func-
tionality of the LED and the cluster control circuitry.
The PCM continually monitors the engine temper-
ature, oil pressure, and electrical system voltage,
then sends the proper messages to the instrument
cluster. For further diagnosis of the check gauges
indicator or the instrument cluster circuitry that con-
trols the LED, (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER - DIAGNOSIS AND TESTING).
For proper diagnosis of the PCM, the PCI data bus,
or the electronic message inputs to the instrument
cluster that control the check gauges indicator, a
DRBIII scan tool is required. Refer to the appropri-
ate diagnostic information.
CRUISE INDICATOR
DESCRIPTION
A cruise indicator is standard equipment on all
instrument clusters.
equipped with the optional speed control system, this
indicator is electronically disabled. The cruise indica-
tor is located near the upper edge of the instrument
cluster, to the left of center. The cruise indicator con-
2
sists of a stencil-like cutout of the word "CRUISE" in
the opaque layer of the instrument cluster overlay.
The dark outer layer of the overlay prevents the indi-
cator from being clearly visible when it is not illumi-
nated. A green Light Emitting Diode (LED) behind
the cutout in the opaque layer of the overlay causes
the "CRUISE" text to appear in green through the
translucent outer layer of the overlay when the indi-
cator is illuminated from behind by the LED, which
is soldered onto the instrument cluster electronic cir-
cuit board. The illumination intensity of the cruise
indicator is one-step dimmable. When the exterior
lighting is turned On, the indicator is dimmed; and,
when the exterior lighting is turned Off, the indicator
is illuminated at full intensity. The cruise indicator is
serviced as a unit with the instrument cluster.
However, on vehicles
TJ
not