INDICATORS
Indicators are located in various positions within the CCN and are all connected to the CCN electronic circuit board.
The door ajar indicator, cargo lamp indicator, high beam indicator, and turn signal indicators operate based upon
hard wired inputs to the CCN. The brake indicator is controlled by CAN data bus messages from the Controller
Antilock Brake (CAB) as well as by hard wired park brake switch inputs to the CCN. The seatbelt indicator is con-
trolled by the CCN programming, CAN data bus messages from the Occupant Restraint Controller (ORC), and a
hard wired seat belt switch input to the CCN. The Malfunction Indicator Lamp (MIL) is normally controlled by CAN
data bus messages from the Powertrain Control Module (PCM); however, if the CCN loses CAN data bus commu-
nication, the CCN circuitry will automatically turn the MIL on until CAN data bus communication is restored. The
CCN uses CAN data bus messages from the Totally Integrated Power Module (TIPM), the ORC, the CAB, and the
Sentry Key REmote Entry Module (SKREEM) to control all of the remaining indicators.
The various CCN indicators are controlled by different strategies; some receive fused ignition switch output from the
CCN circuitry and have a switched ground, while others are grounded through the CCN circuitry and have a
switched battery feed. However, all indicators are completely controlled by the CCN microprocessor based upon
various hard wired and electronic message inputs. The cruise indicator located within the VFD unit is dimmable. All
other indicators are illuminated at a fixed intensity, which is not affected by the selected illumination intensity of the
CCN general illumination LED’s. The illumination intensity of the dimmable indicators is synchronized with that of the
CCN general illumination LED’s.
In addition, certain indicators in this instrument cluster are automatically configured or self-configured. This feature
allows the configurable indicators to be enabled by the CCN circuitry for compatibility with certain optional equip-
ment. The CCN defaults for the ABS indicator and airbag indicator are enabled, and these configuration settings
must be programmatically disabled in the CCN using a diagnostic scan tool for vehicles that do not have this equip-
ment. The automatically configured or self-configured indicators remain latent in each CCN at all times and will be
active only when the CCN receives the appropriate CAN message inputs for that optional system or equipment.
The hard wired indicator inputs may be diagnosed using conventional diagnostic methods. However, the CCN cir-
cuitry and CAN/LIN bus message controlled indicators are diagnosed using the CCN self-diagnostic actuator test.
Some indicators are requested to be turned on via the LIN bus. (Refer to 8 - ELECTRICAL/INSTRUMENT CLUS-
TER - DIAGNOSIS AND TESTING). Proper testing of the CAN/LIN data bus and the electronic message inputs to
the CCN that control an indicator requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic
information. Specific details of the operation for each indicator may be found elsewhere in this service information.
CLUSTER ILLUMINATION
The CCN has several illumination lamps that are illuminated whenever the exterior lighting is turned On. The illu-
mination intensity of these lamps is adjusted when the interior lighting thumbwheel on the headlamp switch is
rotated (down to dim, up to brighten) to one of six available minor detent positions. The CCN monitors a resistor
multiplexed input from the headlamp switch on a dimmer input circuit. In response to that input, the CCN electronic
circuitry converts a fused 12-volt input it receives on a hard wired panel lamps dimmer switch signal circuit into a
12-volt Pulse Width Modulated (PWM) output.
The CCN uses this PWM output to control the illumination intensity of the cluster, the instrument panel center stack
illumination, and the VFD unit on the CCN circuit board. The CCN also transmits electronic dimming level messages
over the LIN data bus to other electronic modules (such as the ASBM, HVAC control head, the radio, and the clock)
in the vehicle to control and synchronize their illumination intensity.
In addition, the thumbwheel on the headlamp switch has a Parade Mode position to provide a parade or funeral
mode. The CCN monitors the request for this mode from the headlamp switch, then transmits an electronic dimming
level message to illuminate all VFD units in the vehicle at full (daytime) intensity for easier visibility when driving in
daylight with the exterior lighting turned on.
The hard wired headlamp switch and panel lamps dimmer inputs to and outputs from the CCN may be diagnosed
using conventional diagnostic methods. However, proper testing of the PWM processing of the CCN and the elec-
tronic dimming level messages sent by the CCN over the CAN data bus requires the use of a diagnostic scan tool.
Refer to the appropriate diagnostic information.
PM
INSTRUMENT CLUSTER - SERVICE INFORMATION
8J - 53