Electrical 389 Family
Peterbilt Motors Company 6-10
The central instrument cluster receives input data from the ICU/CECU via the I-CAN data bus. When the ignition key
is first turned ON, the cluster performs a calibration power
on self-test.
Power On Self-Test
Ignition key turned ON.
The speedometer and tachometer gauge pointers move from pointing at zero, counter-clockwise to their
mechanical limit (approx. -8°), remain there for 1 second and return to pointing at zero.
At the same time, all LED indicators and telltales are switched on together, and then switched off together.
A warning sound sequence is also activated five times without a break.
The warning lamps in the cluster are all activated by the ICU/CECU, Three screens will sequentially display
warning icons on the Driver Information Dis¬play. The ICU/CECU receives direct wire inputs for all warning lamps
with the exception of the Low Cool¬ant Level warning and the Traction Control/Stability Control lamp. These lamp
inputs are received via the J1939 (vehicle CAN) data link. The ICU/CECU typi¬cally receives the Trailer ABS
warnings via the J1939 (Vehicle CAN) data link, however it can also be di¬rect wired to the ICU/CECU from the
ABS unit on the trailer, if required.
NOTE: Before replacing the ICU/CECU or any gauges, check the wiring and fuses, and perform the diagnostic tests using
ESA to verify that you are not replacing a good component.
Commercial Vehicle Smart Gauges (CVSG)
The right and left instrument panel gauges used with the multiplexed instrumentation are commonly referred to as
Commercial Vehicle Smart Gauges (CVSG). Like the central instrument cluster, the 2-inch gauges also receive input data
directly from the ICU/CECU. CVSG’s are electronic and mechanical. The electronic CVSG’s receive digi¬tal data from the
ICU/CECU via the CVSG data bus. The mechanical gauges (i.e. suspension air pressure, etc.) are driven directly from the
air pressure. Both types of gauges receive input signals from the ICU/CECU via a 4-wire “daisy chained” jumper harness
that links one gauge to another. When the ignition key is first turned ON, all the electronic 2-inch gauges will perform a
calibration “power on self-test.”
Power On Self-Test
Ignition key turned ON.
The gauge pointers move from pointing at zero, counterclockwise to their mechanical limit (approx. ¬5°), remain
there for 1 second and return to pointing at zero.
At the same time, all LED indicators are switched on together, and then switched off together.
Additional CVSG gauge information service technicians should be aware of:
2-inch electronic gauges receive their power from the ICU/CECU.
Yellow = Power wire (9-16 volts)
Green = Ground (Return) wire
The ICU/CECU sends 2-inch electronic gauges information over a data link (blue wire) between the ICU/ CECU
and the gauge.
4-way jumper harnesses link each 2-inch gauge together.
Yellow = Power wire
Green = Ground (Return)
Blue = Data link
Brown = Backlighting (used for mechanical gauges only)
Backlighting for 2-inch electronic gauges is sent from the ICU/CECU to the gauges via the data link (Blue wire).
If the headlamps are on and the dimmer is turned to bright, you can scan the panel and tell which elec¬tronic
gauges are wired and functioning correctly.
