(EBV) system . This indica tor is contr olled by a tra n-
sistor on t he instrument cluster circuit boa rd based
upon cluster programmin g, elect ronic m essa ges
received by th e cluster from th e Cont roller An tilock
Brake (CAB) over t he Con troller Area Network
(CAN) data bu s, a nd a ha rd wired input from th e
brake fluid level switch. Th e br ake indicator Light
Emitting Diode (LE D) is complet ely cont rolled by t he
instr umen t cluster logic circu it, a nd th at logic will
only allow t his indicator to oper ate when th e instru-
ment cluster detect s th at the ignition switch is in t he
On posit ion. Therefore, the LED will a lways be off
when t he ignition switch is in an y position except
On. The LED on ly illuminates when it is provided a
pa th to grou nd by the instr umen t cluster tra nsistor.
The instru ment cluster will tu rn on th e brake in dica-
tor for the following rea son s:
• Bulb Test - Ea ch time the ignition switch is
turned t o the On position the bra ke in dicator is illu-
minated by the instr umen t clust er for abou t two sec-
onds as a bulb test .
• Brake Fluid Level Switch Input - Each t ime
the cluster detects gr ound on the bra ke indica tor sig-
nal circuit (bra ke fluid level switch closed = brake
fluid level low) wh ile th e ignition switch is in th e On
position , th e brake indicator is illuminated. Th e indi-
cator remains illuminated un til the bra ke signal indi-
cator input to t he cluster is an open circu it (br ake
fluid level switch open = brake fluid level okay), or
until the ignition switch is t urned t o t he Off position,
which ever occurs first.
• Electronic Brake Force Distribution (EBV)
In dic ato r La m p -On Me s s ag e - Ea ch time th e clus-
ter receives a EBV indica tor lamp-on message fr om
the CAB, th e indica tor will be illuminat ed. The indi-
cator rema ins illu minated un til the cluster receives a
lam p-off message fr om the CAB, or until th e ign ition
switch is tur ned to the Off posit ion, whichever occu rs
first.
The CAB contin ually monitors the EBV system cir-
cuits and sensors to decide whether t he system is in
good oper ating con dition. The CAB then sen ds the
pr oper lamp-on or lamp-off messa ges t o the instru-
ment cluster. If th e CAB sends a lam p-on message
after th e bulb test, it indica tes t hat the CAB has
detected a syst em m alfu nction a nd that t he EBV sys-
tem ha s become inoper ative. The CAB will store a
Diagnostic Trou ble Code (DTC) for any ma lfun ction it
detects.
The brake fluid level switch in t he br ake ma st er
cylinder provides a hard wired gr ound inpu t t o th e
instr umen t cluster circu itry t hrough the brake indi-
cator signal circuit whenever the flu id level in the
brake m aster cylinder is low. The switch is connect ed
in par allel between gr ound a nd th e instru ment clus-
ter. The br ake fluid level swit ch and th e inpu t circuit
to t he instru ment clust er can be diagn osed using con-
vent iona l dia gnostic tools and meth ods. F or pr oper
diagnosis of the instr umen t cluster circuitr y that con-
trols the brake indicator, a diagnostic scan tool is
required. Refer to the appropriate diagn ost ic infor-
mation.
BRAK E WEAR I N DI CAT OR
DESCRIPTION
A brake wear in dicator is standard equ ipment on
all instrument clu st ers. The br ake wea r indica tor is
locat ed nea r th e lower edge of th e in st rumen t clu st er,
to the left of the m ulti-funct ion in dicator display. The
brake wea r indica tor consist s of t he Internationa l
Contr ol and Display Symbol icon for “Worn Br ake
Linings” im printed with in a rectangular cut out in the
opa que la yer of th e instr ument cluster overla y. The
da rk outer la yer of the overlay pr events t he in dicator
from being clear ly visible when it is not illum inated.
An am ber Ligh t Emitting Diode (LED) behin d the
cutout in the opa que la yer of the overla y causes the
icon to a ppea r silh ouett ed again st an amber field
through the tr anslucent out er layer of the overla y
when the in dicator is illuminat ed from behind by the
LED, which is soldered on to th e instr ument clu st er
electronic circuit board. Th e brake wea r in dicator is
serviced as a un it wit h the instr umen t cluster.
OPERATION
The bra ke wea r indicator gives an indica tion to the
vehicle opera tor when the bra ke linin gs h ave rea ched
their wear limit s. Th is indicator is con trolled by a
transistor on the instrument cluster circuit board
based upon cluster progr amming a nd a har d wired
input from the fou r brake wear sen sor s, one at each
wheel. The brake wear indicator Light Emitt ing
Diode (LED) is completely controlled by the instr u-
ment cluster logic circuit, an d t hat logic will only
allow this indicator to opera te when the inst rument
cluster detect s tha t th e ign ition swit ch is in t he On
position . Ther efore, the LED will alwa ys be off wh en
the ignition swit ch is in any position except On . The
LED only illu min ates when it is pr ovided a path t o
ground by the instru ment cluster transistor. Th e
instr umen t cluster will tu rn on th e bra ke wear indi-
cator for th e following rea son s:
• Bulb Test - Ea ch time the ignition switch is
turned to th e On position the brake wear indicator is
illuminated by th e instr ument clu st er for about two
seconds as a bulb test .
• Brake Wear Sensor Input - Each time the
cluster detects gr ound on the brake wear sense cir-
cuit (brake wear sensor closed = brake linin g wear
lim it exceeded) wh ile the ignit ion switch is in the On
position , th e brake wear indica tor is illuminated. Th e
indicator remains illum ina ted unt il t he bra ke wear
sense input to the cluster is an open circuit (bra ke
wear sensor open = brake lin ing wear within lim its),
VA INSTRUMENT CLUSTER 8J - 13
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