10:03-08
Issue 1
en
Testing brake system
Contents
General
... 5Equipment
... 6Location of components
... 12Test connection
... 14Checking pressure gauges
... 16Operating pressure, integrity,
overflow valve
Test stage 1 ... 20Anti-freeze unit
Test stage 2 ... 24Four-circuit protection valve, types
1, 3
Test stage 3a ... 26Four-circuit protection valve, types
2, 4, 5
Test stage 3b ... 30Parking brake, emergency brake,
pressure limiting valve 58b, relay
valve
Test stage 4 ... 34Fault codes, Configuration
Test stages 5 and 6 ... 38Lining wear sensor
Test stage 7 ... 42Checking warning lamps, sensors
Test stage 8 ... 44Pedal position sensor
Test stage 9 ... 46Load sensing pressure sensor
Test stage 10 ... 48Communication
Test stage 11 ... 52Signal from exhaust brake to EBS 2.2 ... 52
DBR Signal ... 53
Engine, torque limitation ... 54
Service brake valve
Test stage 12 ... 56Brake starting pressure
Test stage 13 ... 58Control modules
Test stage 14 ... 60Trailer relay valve
Test stage 15 ... 62Trailer control module, TCM,
EBS 2.2
Test stage 16 ... 64Trailer relay valve/control unit,
discharge function
Test stage 17 ... 66Communication with trailer
equipped with EBS
Test stage 18 ... 68Secondary brake valve, T-vehicles
4x2, EBS 2.2
Test stage 19 ... 69Wheel sensors
Test stage 20 ... 70Retarder torque
Test stage 21 ... 72General
The illustrations contained in this booklet originating from Scania Diagnos are from version 2.14. The layout may differ in new versions of Scania Diagnos.
IMPORTANT! Make sure the pressure gauges being used are checked and calibrated.
EBS components
• Many components and their functions can
easily be checked using the Read/Activate function in Scania Diagnos.
The help button in each diagnosis window will display a description of what the different buttons are used for.
Note: The layout of the diagnosis window will also differ depending on the EBS system being tested.
Equipment
1 Measuring panel 98 600
• Panel comprising three pressure gauges,
0-2.5 bar, fitted in a metal case.
• A Plexiglas disk permanently screwed to
the metal casing protects the pressure gauges from the front. The connection to each pressure gauge contains a damping device and a T-pipe equipped with a 3/8" insert nipple and a safety valve set to 2.5 bar.
2 Measuring panel 99 399
• Two built-in pressure gauges, 0-15 bar,
without safety valve.
3 Pressure gauge 99 215
• A loose pressure gauge 0-15 bar, without
safety valve.
4 Relief valve 98 703
• The relief valve is designed to control
the other pressure gauges.
5 Adapter 99 401
6 Pressurising hose with connections, 98 243
• The hose is equipped with a cap nut at
one end and a threaded adapter connection at the other. It also has a check valve and a test connection. The hose is used when charging the
compressed air system of the vehicle with workshop air.
7 Connector for connecting hose 98 706
• These connectors are used for linking
connection hoses for trailer brake tests etc.
8 Connection hose 99 164
• Fabric-reinforced plastic hose with cap
nut at one end and quick coupling at the other. The hoses are used to connect the pressure gauges to the test connections. The hoses can be joined using connector 98 706 when testing trailer brakes etc.
9 In-house manufactured tools
Duo-Matic, ISO and BSI kits can be ordered to brake testing trolley 588 477. See tool sheet 588 477 for component parts.
Due to the various designs of trailer brake couplings, hoses 98 605 are supplied without couplings. Connect the couplings as follows:
• Duo-Matic fittings:
Drill out the rivets holding the plate on the cover using a 5 mm drill. Cut a thread using an M6 tap and attach the handle with an M6x12 mm bolt. Make two versions, one for trucks and one for tractors. Use handle 99 402 for trucks.
• ISO connection:
Use a T-union WR 1/4" and test connection 215 619.
• Duo-Matic coupling, trailer section Equipped with a test connection in the feed line connection.
1 Feed line 4 Control line • ISO connection, trailer section
Equipped with a test connection in the feed line connection.
1 Supply cable (red) 4 Control cable (yellow)
• BSI connection, trailer section
Location of components
3 C ompr es sor 4 B ra ke c hambe r 7b
Air tank, parking and tr
ailer br ake cir cui ts 7c Air tank, fr ont cir cui t 7d Air tank, r ear c ir cuit 7k
Air tank, air dryer
10a (T 4) Low p ressur e indicator for supply pr essur e, par ki ng br ak e cir cuit 10b (T 3) Low p ressur e indicator for se rvice pr essur e, par ki ng br ak e cir cuit 12 Se rv ice br ak e v a lve 13 Safety v a lve ( 14.3 ba r) 16 (T 1) Pr essur e sensor wit h m o n itor , fr ont cir cui t 16 (T 2) Pr essur e sensor wit h m o n itor , r ear cir cui t 19b Re la y valve, par ki ng br ak e cir cuit 20d Manual c o n tr o l v a lve , tr ailer br ak e c ir cuit 23 Double c h ec k v a lve 25 T rai le r br ak e coupli n g 26 (O 10) Indicating ins trume nt , fr ont c ir cuit pr essur e 26 (O 11) Indicating ins trume nt , r ear cir cuit pr essur e 27 Spring br ak e c hamber 28 F il le r nipple , parking br ak e c ir cuit 32 Dr ain v a lve 35 Safety v a lve , 19 bar 36
Air tanks, air s
u spe n si on 39 Ove rflow val ve 52 Interloc k v a lv e 55 T est connection, f iller nippl e 57 T raile r r el a y v a lv e 58b Pr essur e l imiting valve (8 bar), parking and t rail er br ak e cir cuit (7.3 bar for US-adapted br ak e sy st em s) 58c T w o-sta g e pr essur e limit ing valve ( 9.3 bar) for 12.2 bar system s 60 F our -c ir cuit pr otec ti on valv e 61d Manual contr o l valve, parking br ak e ci rc u it 65 Manifol d f itt ing 74 (H4) A ir drye r w ith int egr ated pr essur e re gulator 84 (N1) Buzzer C56 Junction b loc k, CAN signals C92 T ra ile r c oupling D39 P edal posit ion sensor E43 EBS contr o l unit P2 C entr a l elec tr ic unit S50 Dia gnost ics pane l S90 T C -Of f Road swit ch T13 W hee l s ensor T28 W hee l s ensor T46 L oad se ns ing pr es su re sensor T73 A ir s u spe n si on le ve l se ns or V48 T ra iler contr o l module, T C M V80 S ec o ndary br ak e valve V82 C ontr o
l module, axles 1 and 4, left
-hand si de V83 C ontr o l module
, axles 1 and 4, right
-hand side V84 C ontr o l module
, axle 2, left-hand side
V85
C
ontr
o
l module
, axle 2, right-hand side
V86 Contr o l module , axle 3 V95 C ontr o l module , axle 2, EBS-2.2 V96 C ontr o l module , axle 3, 6x 4, EBS-2.2 W3 W a rning la m p, T C W6 W a rning la m p, l o w cir cui t pr essur e W7 W a rning la m p, par ki ng br ak e W8 W a rning la m p, ABS/ E BS W15 W arning la m p, ABS/ E BS, t rail er W16 W arning la m p, t rail er w ithout A B S/ EB S W18 W arning la m p, w o rn br ake pads Location of components
Test connection
A colour-coded brake circuit diagram is available in the electronic version of this booklet as well as in main group 10, Testing brake system, Test connection
A Suppl y c ircuit D Tr ailer bra k e c ir cuit B F ront c ir cuit E Ac cessor y c ircuit C R ear c ir cuit F P arking brake circuit Test connection
S o ck et N o . C ircu it of f eatu re to be test ed L o cat ion 1 C ha rging with w o rkshop air In l eft-ha n d step 1A Measur
ing supply circ
ui t pre ssure (on ve hi cl es with 12.2 ba r syst em ) Must n o t b e u sed for chargin g with wor k shop air O n t h
e air suspension air tank, in fr
ont of t h e overf lo w va lve 2 R ea r c ircuit, suppl y pr essure A d ja cent to servic e bra k e valve 3 R ea r c ircuit, service pressure , bac kup pr essure In centre valve a ss embl y, bottom connec tion (R) 4 P ar
king and trailer
brake
circuit supply pressure
A d ja cent to servic e bra k e valve 5 B ra ke pr essure f
rom control modul
e O n eac h brake chamber 7 P ar king brake , control pressure O n t h e rea r spring brake cha m be rs 8 T railer brake , service pressure
For test conne
ctions c onnec te d t o tra il er bra k e coupling, see In -house manufa cture d t ools 9 F ront c ircuit, service pressure , backup pr essure In centre valve a ss embl y, top conne ction (F ) 10 R ear c
ircuit load-sensing valve
, air spring pressure
Beside solenoid va lv e bl oc k for a ir sus p en si on 11 F our -circ u it prote ction va lve, ac cessory ci rcuit O ne o f the outputs on coupli ng 65, s elect one of t h e coupl ings. N o te:
Fit a test connec
ti on on the a ppropriate coupli ng. 12 F ront c ircuit, supp ly pre ssure A d ja cent to servic e bra k e valve 13 Trailer brake , supp ly pre ssure
For test conne
ctions c onnec te d t o tra il er bra k e coupling, see In -house manufa cture d t ools 14 S upply circ uit , c h eck va lve in overf lo w va lve 39 O n t h
e air suspension air tank, be
hi nd the ove rflow va lv e Test connection
Chec
ki
ng pressure gaug
es
IMPO R T ANT! The pr essure gauge s m u st be used in a suspe n d ed positi on, in the sa me w ay a s when t h ey ar e set t o zer o. Note : Al w ays c heck that the c
ables a n d conne cti ons in the c ir cuits a re a irti ght. Con n ec tion di a g ra m for c h ec ki ng 2.5 bar pr essur e gaug es Mult ime te r w ith con verter fr om me asur ing set 9 9 362 and adapter 99 401 Connec ti on dia g ra m for c h ec king 15 bar pr essur e gaug es Adj u sting scr ew on pr essur e gaug es
Equi p m ent/Pressure gaug es 2.5 bar 15 b a r 33 Test m easu res Pre ssu re gau ge Caus e of fault / action 2.5 bar 15 b a r
2.5 bar pressure gauges - Connec
t adapter 99 401 t o the pr essure r eduction valve. - Connec t t h e adapte r to t h e conver te r. The n c onnec t the converter to m u ltim eter 588 093. - S et the m u ltim ete r to direc t c u rre n t volt age and t u rn on t h e converte r. - Z
ero the multi
me te r by turning t h e conver te r set scr ew ma rked z ero. - Z
ero the indica
to rs on the pressure gauges. -
Turn the knob anti
clockwise until t h e rel ief valve i s closed. - Connec t t h e air hose f rom t h
e workshop air system to the
re lie f val v e. - Connec t t h e t h re e hose s from the re li ef valve to ea ch pr essure ga uge. - T u rn the re li ef
valve knob cloc
kwis e unti l the pre ssure gauge s a nd the multim et er show a pproxi mat el y 1 b ar. The voltage rea d
ing shown in the multi
mete r window co rre sponds to the pr essure in bar .
Check that the pr
essure ga uge value a g ree s wit h the va lue on the m u ltim ete r with a tole ranc e of +/- 0.025 ba
r/V. If it does not, return the
pressure gauge for ca li br ation. - Chec k that th e pressur e gauge s show the s ame. 1.0
- Ra is e t h e air pre ss u re using t h e relief valve to 1.5 and 2.0 ba r and c h eck tha t the pr essure ga
uges and the
multim et er cor respond. - I n cre ase a ir pressure to 2.5 b ar, at whic h po
int the saf
ety va lves shoul d ope n. 2.5 The ope ni ng pr
essure is adjusted by turning the
adjusti
ng slee
ves on the saf
ety valves.
15
bar pressure gauges
- Se t the displa ys to z er o. - Connec t an air hose t o e ach pr essure ga uge. - T u
rn the knob clockwise until the pres
sur e gauges show 5b ar . 5.0 - Chec k that th e pressur e gauge s c o rre spond . C
heck that the pr
essure ga uge value a g ree s wit h the va lue on the m u ltim ete r with a tole ranc e of +/- 0.1 ba
r/V. If it does not, return the
pressure gauge for ca li br ation. - Ra is e t h e air pre ss u re to 6 and 7 b ar and che ck that the pr essure ga uges cor respond. Test m easu res Pre ssu re gau ge Caus e of fault / action 2.5 bar 15 b a r
1. T
e
sting
opera
ting pres
sure
,
s
eal integrity and c
h
ec
k
v
a
lve in o
ver
flo
w
v
a
lv
e (39)
Note the r eading in the re po rt acc om pa n y ing thi s booklet. Equi p m ent/Pressure gaug es 2.5 bar 15 b a r --3 T es t c onnections 1A and 14 T est c onnection 1 100668 T es t c onnection 12 1 2 2526 10 Test stage 1Test m easu re T es t conn ec tion (b ar ) C ause of f a u lt / act ion 12 1A Ve h icle s wi th load h a nd lin g t a n k s - Connec t 15 b ar pre ssure ga u g e to t est c
onnections 12, 1 and 1A.
- Start the e ngi ne and c h ar ge the sy ste m . - Chec k the re li ef pressure at test connec ti on 1A b y
noting when the
pre
ssure
at t
est
conne
ction 1 drops. Che
ck the pre ssure l imit ing va lve (58c) a t te st c onnection 12. 9.1 - 9.5 12.0 - 12.4 - D ecr ease t h e syst em pr essure by dr aining t h e first l o ad handling t ank. - N o te the pre ssur e at test conne cti on 1A when the c o m p re ssor starts to ch arge . The c o m p re
ssor starts cha
rging when the pre
ssure r
ise
s a
t t
est
connection 1. Calculate the
pressure di ff er ence t o obta in the ope rating ra nge of t h e compre ss or . 10.4 - 11.5 Chec k ing th e check valve in t h e overf lo w val ve (39) - Move t h e pressure gauge f
rom test connec
tion 1A to test connec
ti
on 14.
- D
rain the fir
st load ha ndl ing tank. - T h e pre ssur e at test conne cti on 14 must not dr op. If t h e pressure at test connec ti on 14
drops, the ove
rflow va lv e (39) must be re p lac ed . Ve h icle s wi th out load hand lin g tanks - Connec t 15 b ar pre ssure ga u g es t o te st c onnections 12 and 1. - Start the e ngi ne and c h ar ge the sy ste m . - Chec k the re li ef pressure at test connec ti
on 12 by noting when the
pr essure a t t est c onnection 1 drops. 9.1 - 9.5 - D ecr ease t h e syst em pr essure by r epea tedly depre ss ing the br ake pe dal. - N o te the pre ssur e at test conne cti on 12 w h en the compre ss or st ar ts t o ch arge . The c o m p re
ssor starts cha
rging when the pre
ssure r
ise
s a
t t
est
connection 1. Calculate the
pressure di ff er ence t o obta in the ope rating ra nge of t h e compre ss or . 7.9 - 8.9 Test stage 1
Seal in te grity - Fill the s y stem to oper ati ng pr essure. - Fully depre ss the br ake pe dal. Wa it 30 sec onds. Re ad and re cord the pr essure. - K eep the pe dal depr essed a f u rther 1 minute. - Re ad and re cord the pressure . < 0.2 bar drop If pressure drop is gr ea te r, the lea k must be repa ir ed befor e continuing the te st. Test m easu re T es t conn ec tion (b ar ) C ause of f a u lt / act ion 12 1A Test stage 1
2. Che
c
king anti-fr
e
e
z
e unit
!
W ARNI N G ! R e leas e the air f rom t h e s y s te m bef o re remo v ing t h e desiccant cont ainer Halde x design 1 H alde x de si gn2 W abco Air d ryer R esistance Ha ldex and W abco 5.0 -7.5 ohm at temp < + 7 °C Test stage 2Test m easu re Cause of f a u lt / act ion Air d rye r Wh en th e co m p re sso r i s r elie v in g lo ad , the dr
ain valve should open. The a
ir in the dr yer should t h en be e v ac ua te d. Eva cuation takes up to 40 seconds. - N o te the c o mple te d fun cti on che ck in the bra k e te st report. - Chec k that th e drain va lv e in the bot
tom of the drye
r does not lea
k
when the compre
ssor is char g ing. Ch ec ki n g the he ater el em ent - Start the e ngi ne and c h ec k whe th er ther e is a supply voltage in the connec tor t o the air drye r hea te r el ement, 24 -28.8 volt s Air d rye r te mperat u re below +7° Rec tify the air drye r if it is not oper ating i n a cc o rdance with t h e t est stage s, se
e main group 10 in the
Servic e Manual, Suppl y c ircuit co m pone nt s. - Start the e ngi ne and fe el to see if the u nde rside of the dr yer he ats up wit h in a c ouple of minut es . The te m p er ature shoul d r ise t o 20-30 °C , whic h is the switc h-off te mpe ra ture of t h e th ermosta t. Air d rye r te mperat u re abov e +7° - Re m ove t h e P 2 /H c ont ac t in t h e centr al elec tr ic unit . - Connect a mul timeter s
et for measuring resistance between ground and the green wire marked 61
C on pin 12 in the H c o nta ct. - Plac e the mult imeter on t op of t h e ins trume nt pa nel with i ts displ ay window fac ing the wind sc ree n . - T ilt the ca
b or drop down the bonne
t. Remove t h e cover over the a ir dryer . - Re m ove t h e desicca nt container . - Cool down
the air dryer
as il lustrate d using e.g. cooling spra y unti l it is below +7 °C, which i s the ope ni ng tem p
erature of the ther
m o stat. Spray at inter v als t o all o w time for t h e cold to propagat e through t h e mat eria l. - Me asure the resi st ance at t h e cont ac t. Test stage 2
3a.
T
estin
g f
o
ur
-cir
cu
it p
ro
tecti
on
v
a
lve type 1 and
typ
e
3
Equi p m ent/Pressure gaug es 2.5 bar 15 b a r --3 T ype 1 W abc o T est conne cti on 1 10_2704 100668 T ype 3 K norr T es t c onn ec tions 2, 4 an d 12 4 2 12 15 1003 Test stage 3aTest m easu re T es t conn ec tion (bar) C au se of faul t / action 12 4 1 1 1 2 C h ec k ing t h e o p en ing p re ssu re The onl y c ir cuit t h at
needs to be tested is the pa
rking b rake ci rc uit, s inc e legal provisions st at e that it must not be ch arge d b efore the servic e bra k e circ uit s ha v e re ache d em er genc y brake pressure . - Ev ac u at e th e sy st em. - C onne ct 15 ba r pr essure gauge to test conne ctions 2, 4 a nd 12. - Ch ar ge t h e syst em and c h eck t h at t h e pr essure i n t h e fr ont and rea r cir cuit s is at lea st 5 ba r bef o re the pa rking brake ci rcuit clea rly opens. > 5.0 > 5 .0 If t h e va lu e i s in co rre ct , repl ac e the va lve. Ch ec ki n g cl osin g pr essu re Fr on t c ircuit and re ar c ir cui t - Char
ge the system to at least 7.5
bar
and make sure
the co mpressor is in char gi ng mode. - Connec t a 15 bar p ressure g auge to the re ar c ircuit test connection 2, the fr ont c
ircuit test connec
tion 12 and te
st
connection, filler nipple 1. - Drai
n t h e a cce ssor y ci rcui t. - Chec k that th e pressur e in t h e rea r cir cuit a nd th e front ci rcuit is not be lo w 4 b ar and the te st c onnection, fill er nipple dr ops to ze ro. 0.0 > 4.0 > 4 .0 If the va lu e is inc o rre ct, replac e the va lve. Test stage 3a
Par k ing b rake c ircuit an d acc essory c ir cui t - Char
ge the system to at least 7.5
bar
and make sure
the co mpressor is in char gi ng mode. - Connec t a 15 bar p ressure g
auge to the par
k
ing br
ake
ci
rcuit test connec
tion 4, the a cce sso ry circ ui t test
connection 11 and test conne
ction, fil le r nippl e 1. - D rain the re ar c ircuit by fitt ing a pr essurising ho se to te st connection 2. - Ch ec k that the pressure in t h e par k ing br ake circuit and th e ac ce ssory circ ui t is not be low 4 b ar, a nd t h e t est c onnection fi ll er ni pple drops t o z ero. The pressure in t h e parking br ake c ircuit wil l c ont inue to drop be ca u se it doe s not ha ve a c h ec k v alv e. 0.0 > 4.0 > 4.0 If the va lu e is inc o rre ct, replac e th e v al v e. Test m easu re T es t conn ec tion (bar) C au se of faul t / action 12 4 1 1 1 2 Test stage 3a
3b.
T
e
st
ing
f
o
u
r-ci
rcui
t pr
o
tectio
n
v
a
lve
typ
e
2,
4 and
5
Equi p m ent/Pressure gaug es T ype s 2, 4 a nd 5 are simil ar . T h e dif fe renc e be twee n the m is that the re is a b ypa ss function in ty pes 4 and 5 that drains the
parking bra k e c ir cuit i f t h e rea r circ uit is empty . T ype 5 has incre ased ope n ing pressur e and is found on T -v ehicles. T ype 4 is prese n t as from cha ssi s number : T ype 5 is prese n t from 2001-09, T -v ehicles. 2.5 bar 15 b a r --3 Sc an ia S ö dert äl je 1 261 040 S ca n ia Nethe rla nds S cania Ange rs T yp es 2, 4, 5 W abco T est c onnection 1 100668 T ype s 4 a nd 5 W abc o T es t c onn ec tions 2, 4 an d 12 4 2 12 100315 Test stage 3b
Test m easu re T es t conn ec tion (bar) C au se of faul t / action 12 4 1 1 1 2 C h ec k ing t h e o p en ing p re ssu re The onl y c ir cuit t h at
needs to be tested is the pa
rking b rake ci rc uit, s inc e legal provisions st at e that it must not be ch arge d b efore the servic e bra k e circ uit s ha v e re ache d em er genc y brake pressure . - Ev ac u at e th e sy st em. - Connec t 15 bar pr essure gauge s to test connections 2, 4 and 12. - Ch ar ge t h e syst em and c h eck t h at t h e pr essure i n t h e fr ont and rea r cir cuit s is at lea st 5 ba r bef o re the pa rking brake ci rcuit clea rly opens. > 5.0 > 5.0 If the va lu e is inc o rre ct, replac e th e v al v e. Ch ec ki n g cl osin g pr essu re Fr ont c ircu it - Connec t a 15 bar p ressure g
auge to the test conne
ctio n, fi ll er ni pple 1. - Char
ge the system to at least 8.5
bar
and make sure
the co mpressor is in cha rging mode . Dr ain t h
e front circuit and
read of f the pre ss u re gauge . > 4.0 If the va lu e is inc o rre ct, replac e th e v al v e. Re ar cir cui t - Char
ge the system to at least 8.5
bar
and make sure
the co mpressor is in char gi ng mode. D rain the re ar c ircuit and read of f the pre ss u re gauge . > 4.0 If the va lu e is inc o rre ct, replac e th e v al v e. Par k in g brak e c ircu it - Char
ge the system to at least 8.5
bar
and make sure
the
co
mpressor is in char
gi
ng mode. D
rain the par
k ing br ake ci rcuit and re ad off t h e pressure gauge. > 4.0 If the va lu e is inc o rre ct, replac e th e v al v e. Ac cessor y ci rcu it - Char
ge the system to at least 8.5
bar
and make sure
the co mpressor is in char gi ng mode. D rain the ac ce ss or y ci rcuit and re ad off t h e pressure gauge. > 4.0 If the va lu e is inc o rre ct, replac e th e v al v e. Test stage 3b
Byp a ss function, typ es 4 an d 5 on ly - A ppl y the pa rking brak e. - Char ge system to relief pressure . - Connec t 15 b ar pre
ssure gauges to par
k ing br ak e c ir cuit te st c onnection 4 and re ar c
ircuit test connec
tion 2 . - D rai n t h e re ar c ircui t. - Chec k that th e pressur e in t h e parking bra k e cir cuit doe s not e x cee d th e speci fi ed v al u e and th at t h e rea r ci rcui t dr op s to 0. 0.0 < 5.0 If t h e v al u e i s i n corr ect , re pl ace th e v alve. Test m easu re T es t conn ec tion (bar) C au se of faul t / action 12 4 1 1 1 2 Test stage 3b
4. T
e
sting
par
k
ing br
ake
/ eme
rg
e
nc
y br
ake
a
n
d function of pr
ess
ur
e limiting
v
a
lv
e
(58b) a
n
d
rela
y
c
h
ec
k
v
a
lve
Equi p m ent/Pressure gaug es 2.5 bar 15 b a r --3 T est conne ction 4 T est conne ction 7 F ill er ni pple 2 8 Interloc k v a lv e 5 2 T est conne ction 8 Test stage 4Test m easu re T est c o n n ec tion (bar) C
ause of fault / action
78 4 Pr essu re limitin g valve ( 58B ) - Char ge the system. Cl ose t h e air supply. - Re ad the pre ssur e gauge at test connec tion 4. 7.7 - 8.3 (7.0 - 7.6) Incorrec tl y adjus ted pre ssure l imit ing valve. Par k ing b rake, e m er gency brake - Plac e choc ks in f ront o f and behind a t lea st two w h eels. - Connec t 15 b ar pre ssure ga u g es t o te st c onnections 4, 7 an d 8 . If the vehicle d o es not ha ve a tr ailer re lay valve ( 57) or tra ile r modul e (V48), only one pr essure ga uge should be conn ec
ted to test conne
ction 7 . - Char ge system to re lief pr
essure. Close the a
ir s upply. 1 Parking bra k e in dr iv e po si ti o n . (T he value s in bra cke ts
only apply to vehicles with
U S -a dapt ed br ake syst em s.) 7.4 - 8.2 (6.7 - 7.5) 0.0 Test conne ction 7: I n corr ectly adjusted pre ss u re lim iting valve (58b) or fa ult y pa rking brake valve (61d) . 2 Le ver to full e m er gency brake p o sition . 0.0 6.6 7.6 (6.0 7.0) Test conne ction 8: I n corr ectly adjusted pre ss u re lim iting valve (58b) or fa ult y pa rking brake valve (61d) or tra ile r re la y valve (57). 3 Le ver in pa rk in g po si ti o n . ( V alve without check position) 0.0 0.0 Le v er in pa rk in g po si ti o n . ( V alve w ith c h ec k positi on) 0.0 6.6 7.6 4 Le ver to test p o sition. 0.0 0.0 Test stage 4
Chec
k
valve in relay valve for
p a rk ing b rak e Pressure
rise at test conne
cti o n 4 indi ca tes de fec tive chec k valve in re la y valve for parking bra k e. - A ppl y the pa rking brake - Plac e whee l chocks on one w h eel. - E v acua te air fr om the parking bra k e circ uit via te st connection 4. A lar g e pre ssur e drop at test conne ction 7 indica tes a lea k i n the control cir cuit or brake chambe rs. - Put the pa rki ng brake in drive position . - Connec t 15 b ar pre ssu re gauge s t o te st c onnections 4 and 7. - Press in the inte rl ock va lve 52 if fitte d a nd cha rge th e pa rking brake circ ui t to 6-8 b ar vi a fill er nipple 28. 6.0 - 8.0 0 .0 - Rea d the pre ssur e gauge at t est c onnec tion 7. Th e p ressu re m u
st not drop more
than 1 b ar in 1 m inu te . Test m easu re T est c o n n ec tion (bar) C
ause of fault / action
78
4
5. Fault codes
• Connect Scania Diagnos.
• Check whether the vehicle has any fault
codes. Rectify active faults immediately.
• Fault codes can arise due to the vehicle
being incorrectly configured.
6. Configuration
• Check the vehicle configuration.
Change the configuration using Scania Programmer if it is not correct.
The following pages contain a description of the Configuration window. Note that different EBS systems use different configuration windows.
1 Wheel configuration: Specified on the type plate on the right-hand side of the cab. 2 Tag axle:
ASA 700 has single-mounted wheels. ASA 1000 has twin-mounted wheels.
101874
3 Trailer control module: The trailer control module is located in the centre valve assembly. Compared with a conventional trailer brake relay valves, the trailer control module has an electric connection. The electric connection is located in towards the frame.
4 Axle distance: Axle distance is the
distance between the centre of the 1st front axle and the centre of the driving axle given in decimetres.
5 Rolling radius: The radius of the driving wheels calculated using the tyre dimensions. Dimension Radius, mm Dimension Radius, mm 10.00R20 511 295/60R22.5 447 11.00R20 525 295/80R22.5 507 11R22.5 510 305/60R22.5 452 12.00R20 545 305/70R22.5 485 12.00R24 595 315/60R22.5 458 12R22.5 526 315/70R22.5 492 13R22.5 546 315/80R22.5 522 14.00R20 601 385/65R22.5 517 275/70R22.5 465 425/65R22.5 542 275/80R22.5 491
6 Rear axle ratio: This value is included on vehicles with EBS2.2 and TCM. The axle gear ratio is stamped on a plate on the rear axle.
7 Weight class:
No. of axles Gross vehicle weight Weight class 2 max. 16000 kg. Low: New Zealand, Australia 3 max. 24000 kg. 4 max. 30000 kg. 2 above 16000 kg. High: Other markets 3 above 24000 kg. 4 above 30000 kg.
8 Service brake valve characteristics are specified on a label hanging from the valve as well as on the valve itself. A comfort value is given in Scania Diagnos for vehicles with TCM (V48).
7. Lining wear sensor
IMPORTANT! The lining wear sensor
measures the total thickness of the brake pad - brake disc - brake pad. This means that the sensor will indicate excessive lining wear if new brake pads are being used with a worn brake disc.
Brake pad wear
• Check the brake pad wear using Scania
Diagnos and note it on the report.
Check the lining wear sensors if abnormal values are indicated, e.g. uneven wear.
Checking lining wear sensors
Note: Fault codes can be set if the contacts are pulled apart when the starter key is in drive position. Therefore, always put the starter key in locking position, 15V supply off
• Check any cables leading to the brake pads
on the brake caliper in question. Not all vehicles or brake pads are fitted with these cables.
• Check that the cable between the brake
caliper and the control module is intact.
• Turn the adjuster screw on the brake
caliper to withdraw the brake pad from the brake disc.
• Put the starter key in drive position, 15V
supply, and connect Scania Diagnos. Take a reading of the brake pad wear.
• Depress and release the brake pedal. Then
take a reading of the brake pad wear from Scania Diagnos. The value is displayed with a certain delay.
If the lining wear sensor is intact, the value after repeatedly depressing and releasing the brake pedal will finally drop to approximately the value read earlier. It will be difficult to obtain the same value as earlier due to the internal tolerances in the lining wear sensor.
• A faulty lining wear sensor will give an
implausible value in relation to the actual wear or a value that does not change during the entire check.
• Renew the brake caliper if the fault can be
traced to the lining wear sensor.
IMPORTANT! Restore the condition of the vehicle and readjust the brakes manually to their basic setting using the adjusting screw. Refer to Workshop Manual, group 10, Disc brakes.
8. Che
c
king warning la
mps
and sensor
s
Equi p m ent/Pressure gaug es 2.5 bar 15 b a r 1P
BRAKE AIR 10_2277 T es t c onnections 2, 4 and 12 4 2 12 15 1003 Test measures Test c o n n ect ion (bar) C ause of f a u lt / act ion 12 2 4 F ront ci rc ui t - Cha rge t h e syst em wi th ai r. - C h eck that the displays in
the cab show f u ll system pressure. - Conne ct the pre ssur e gauge t o te st c onnection 12. - Disconnec t the se
nsors from test conne
cti ons 2 a nd 4. - Drai n the front c ircu it ta nk (7c) until the w arning la mp comes on a nd the buz zer sounds. C h ec k a ls o t h at the signal can be rea d in Sca n ia Diagnos 4.5 - 5.5 Fault i n the s
ensor, lamp or buzz
er.
- C
h
ec
k that the display in t
h
e cab shows the c
o
rre
ct
pressure.
Re ar cir cui t - C h ar ge t h e syst em wi th ai r. - Connec t t h e pressure
gauge to test conne
ction 2 . - D isc onnect the se n sor s f
rom test connec
tions 4 and 12. - D ra in the rea r circ uit ta nk (7d) until th e wa rni ng lam p co mes on a nd the buzz er soun ds. C h ec k a lso tha t th e signal ca n be r ea d in Sca n ia Diagnos 4.5 5.5 Fault in the se ns or , l amp or buzze r. - Chec k that th e dis p la y i n the c ab shows the c o rrec t pr essure. Par k in g brak e c ircu it (fe ed ) - C h ar ge t h e syst em wi th ai r. - Connec t t h e pressure
gauge to test conne
ction 4 . - D isc onnect the se n sor s f
rom test connec
tions 2 and 12. - D rain the pa rking ta nk (7b) until the
warning lamp comes
on
and the buz
zer sounds . C h ec
k also that the
si gna l can be read in Sca n ia Diagnos 4.5 - 5.5 Fault in the se ns or , l amp or buzze r. Par k ing b rake c ircuit (c on tr ol) - C h ar ge t h e syst em . - A ppl y the pa rking brake . - Chec k that th e parking bra k e lamp come s on. Chec k also tha t the signal c an be r ead in Scania D ia gnos Fault in the se ns or or lamp. Test m easu res T est conn ec ti on (bar) C
ause of fault / action
12
2
4
9. P
e
dal p
o
sitio
n
sensor
,
D39
The se ns or comprises tw o potenti ome te rs with in v er ted sign al l evels, one high and the other
lo w . Dia gnosti c wi ndow for p edal pos ition sensor wit h br ak e pe dal f u lly r eleased Dia gnosti c wi
ndow for volt
a g e suppl y t o pe dal positi on se ns or , D39. Test stage 9
Test m easu res Limit valu es C
ause of fault / action
Voltage
su
pp
ly
E43
Troubleshoot the cir
cuit if the values ar e incorr ect. Refe r to components
and wiring diagr
am in Sca n ia Diagnos - C h ec k the vol ta ge supply to the
pedal position sensor f
rom the EB S control unit, E 43. EBS 2 .0: 4.47 - 5.41 V EBS 2 .1: 4.80 -5.20 V EBS 2 .2: 4.55 -5.45 V Pe d a l pos ition sens or D 3 9 - Che ck tha t th e ba rs cha nge re la ti v ely in a line ar f ashion w h il e car efully depre ss ing a nd relea si ng the br ak e pe dal. Potenti o me te r 1 : 0.3 - 4.5 V Potenti o me te r 2 : 4.6 -0.3 V Limit s for fully re le ase d brake pe dal, 0-posit ion: Potenti o me te r 1 : 0.3 -0.5 V Potenti o me te r 2 : 4.4 -4.6 V Test stage 9
10
. Chec
k
ing
load
s
e
nsing pr
ess
ur
e sensor
,
T46
Equi p m ent/Pressure gaug es 2.5 bar 15 b a r 1 -T es t c onnection 10 T 46, Sc ani a D ia gnos EBS 2.2 Swi tc h, mechanical air suspension
Li nk ar m t o le ve l valve , m ec hanical ai r suspension Oper ation unit , ELC S w itc h f o r T73 le vel sensor , elec tr onic air su sp en si o n E L C Test stage 10
IMPO R T ANT! The c o mpressed a ir sys te m must be pre ss u ri se d o v er 9 b ar . Te st me asu re s Te st co n n ec tion (b ar ) S can ia Diagnos C a u se of fau lt / ac tion 10 T46 1a. Lad en ve h icle ,
all air sus
p ension - Connec t S cania Diagnos a n d go to the window f o r L oad se nsi ng pre ssure se nsor T46. - Connec t a 2.5 bar pr essure g
auge to test connec
ti
o
n
10.
- U
se the air suspe
n sion oper ation uni t or the a ir suspension switc hes on t h e in strument pane l. F ill t h e a ir bel lows to a pr essure of 2 b ar a ccor d ing to Scania Diagnos, T46. If a pre ss u re of 2 bar c ann ot be at tained, use m ethod 1b or 1c instead. 2.0 Tr oubl es hoot the
circuit for the
l o ad sensin g pr essure se nso
r if the value is incorr
ect. - Compar e S cania Dia gnos /pre ssure ga uge. Make a note in the re port. 1.5 - 2.5 - T h en dis char g
e the air suspension to a pre
ssure of 0
b
ar
using the oper
ation uni t or the s w it ch es on t h e ins trume nt pa nel. -0.5 - 0.5 0.0 Tr oubl es hoot the
circuit for the
l o ad sensin g pr essure se nso
r if the value is incorr
ect. - Ma ke a note i n the r eport. 1b. Un laden vehi cl e with E L C - U npl ug the a ir suspension l evel sensor, T73. - Connec t a 2.5 bar pr essure g
auge to test connec
ti o n 10. - Connec t S cania Diagnos a n d go to the window f o r L oad se nsi ng pre ssure se nsor T46. - Use the ve hi cl e's air su spe n si on ope ration unit t o f ill the a ir be ll ow s to a pre ss u re of 2 b ar a cc o rding to Sca n ia Dia gnos , T4 6 . 2.0 Tr oubl es hoot the
circuit for the
l o ad sensin g pr essure se nso
r if the value is incorr
ect. - Compar e S cania Dia gnos /pre ssure ga uge. Make a note in the re port. 1.5 - 2.5 Test stage 10
- T
h
en dis
char
g
e the air suspension to 0
b ar using the ope ration unit . -0.5 - 0.5 0.0 Tr oubl es hoot the
circuit for the
l o ad sensin g pr essure se nso
r if the value is incorr
ect. - Ma ke a note i n the r eport. - Plug in t h
e air suspension level sensor, T73.
- Chec
k and c
le
ar f
ault codes that have
been se t in the ELC system whe n t h
e air suspension level sensor w
as unplugged. 1c. Un laden v eh ic le withou t ELC - Deta ch the li nk a rm to the l eve l va lve le ve r. Lock the lev er in drive pos ition so t h e bellows can be fill ed wit h a ir later. - Connec t a 2.5 bar pr essure g
auge to test connec
ti o n 10. - Connec t S cania Diagnos a n d go to the window f o r L oad se nsi ng pre ssure se nsor T46. - Fill the
air bellows to a pre
ssur e of 2 b ar ac cording to Sca n ia Diagnos, T46, using t h
e air suspension swit
ch on the i n strument pane l. 2.0 Tr oubl es hoot the
circuit for the
l o ad sensin g pr essure se nso
r if the value is incorr
ect. - Compar e S cania Dia gnos /pre ssure ga uge. Make a note in the re port. 1.5 - 2.5 - T h en dis char g
e the air suspension to a pre
ssure of 0
b
ar
using the switches on the instrument pane
l. -0.5 0.5 0.0 Tr oubl es hoot the
circuit for the
l o ad sensin g pr essure se nso
r if the value is incorr
ect. - Ma ke a note i n the r eport. - Re le ase the le
vel valve leve
r and r econne ct it to the link ar m. Te st me asu re s Te st co n n ec tion (b ar ) S can ia Diagnos C a u se of fau lt / ac tion 10 T46 Test stage 10
11. Communication
• Signal from exhaust brake to EBS control unit, EBS 2.2
Check that this signal is active as follows: Ensure that the switch for the white smoke limiter is set to the off position.
Turn on the switch for the exhaust brake on the instrument panel.
If the vehicle is equipped with retarder, activate the retarder and set it to maximum position, EB.
Symbol A should now be activated in Scania Diagnos.
If the vehicle is equipped with manual exhaust brake with floor-mounted switch, it must now be activated.
If the vehicle is only equipped with
automatic exhaust brake via the foot brake pedal, the vehicle must be driven. Drive and brake the vehicle. The exhaust brake should now be activated and the symbol A should be activated in Scania Diagnos.
• DBR Signal
Note: This test stage assumes the air system is fully charged.
The DBR signal is used to instruct the other systems to disengage any auxiliary brakes during ABS modulation.
Vehicles with exhaust brake: Deactivate the ABS warning lamp
Then activate the exhaust brake according to Signal from exhaust brake to EBS control unit:
Activate the DBR signal via Scania Diagnos. The exhaust brake should then clearly disengage.
Vehicles without exhaust brake:
Measure the voltage of the DBR signal on junction block C56 /F1.
Activate the DBR signal via Scania Diagnos.
Measure the voltage of the DBR signal on junction block C56. Limit values DBR Signal 0 - 4.5 V active 14.5 - 28.8 V inactive Test stage 11
• Engine, torque limitation
Apply the vehicle's parking brake.
Increase engine speed to 1000 rpm with the accelerator pedal and maintain this speed. Note: Keep the accelerator pedal in this position during the entire test!
Move the slider control to the left. The engine speed should now drop to idling. Move the slider control to the right. The engine speed should return to 1000 rpm. This signal is limited in time. It will stop automatically after five minutes.
The control unit receives information concerning the requested engine torque from the EDC control unit on EBS version 2.2.
Check the communication between them via the bar in Scania Diagnos. The bar should follow the acceleration.
12
. T
esting ser
v
ic
e
br
ake
v
a
lve
IMPO R T ANT! This test s tage must be carried out with t
h e st arter k ey in locking posi tion. 15V of f will t h en pro v
ide backup for
EB S. Note : Whe n me asuring in cr easi n g p ressur e you may onl y de pr ess th e br ak e pe dal or k ee p it sti ll . If t h e bra k e peda l is re le ased w h en m easuri ng incre asing pressure , t h
e test result wil
l be i n co rre ct. Whe n m easuring fallin g pr es sur e you may on ly r elease t h e b rak e p ed a l or k ee p it still . If the br ak e pe dal is de presse d w h en measur ing falli ng pre ssure , the te st re sult will be in correc t. Eq ui pme n t/ Pr essur e gau ges 2.5 bar 15 b a r 2 -T est connec tions 3 and 9 Test stage 12
Test m easu re T es t conn ec tion (bar) C au se of faul t / ac tion 39 - Connec t t h e pressure
gauges to test conne
cti ons 3 a nd 9. - Bra k e in 5 steps acc ording to poi nt 12 on the re port. - Measur e t h e di ffe renc e be tw ee n t h e f ront a n d re ar ci rcui ts . Ma ke a note in the r eport. S ee the re adings i n Te sti ng th e E B S b rak e sy ste m , R eport, m ain g roup 10. If pressure rises or drops in steps, the service brak e valve is st ic ki ng a nd could soo n c ause pr obl em s. Test stage 12
13
. T
esting initia
l brak
e pr
ess
ur
e
IMPO R T ANT! This test s tage must be carried out with t
h e st arter k ey in locking posi tion. 15V of f will t h en pro v
ide backup for
EB S. S p ec if ic ation s Brake star tin g pre ssure Maximum i n
itial brake pres
sur e 0.3 0.5 bar Eq ui pme n t/ Pr essur e gau ges 2.5 bar 15 b a r 1 -T es t c onnection 5, fr ont axle T est conne ctio n 5, r ear axle Test stage 13
Test m easu re T est co n n ec tion (b ar ) C a u se of fau lt / ac tion 5 - Connec t th e pressure gauge to test conne ction 5 . N ot e the rea d ings i n t h e bra k e t est repor t, poi nt 13. The m axim u m br ak e star ti ng pre ssure must l ie betwee n 0.3 -0.5 bar , r egar d le ss of c y li nde r si ze . Re ct ify the bra k es if the initia l pre ssure or the dif fe renc e betwe en the a x le s i s higher t h an sp ec if ica ti on, a s t h is indica te s binding brak e ca li pe rs. See main group 10 in the Ser v ic e Ma
nual, Disc Brak
es . - Rai se t h e ve hic le so tha t the whee l on whic h the initi al br ake pr
essure is being che
cked goe
s free
from the ground.
- Rota te the whe el . - A sk a n assist an t t o slowly depre ss t h e brake pedal. - Re ad the pre ssur e gauge
s when the bra
k es begin to take. 0.3 - 0.5 - Me asure on al l w h eel s. Test stage 13
14.
Chec
kin
g
co
ntr
o
l
modu
les,
v
o
lta
g
e supp
ly
,
regu
lated
pressu
re and
bac
k
u
p
pr
ess
ur
e
Equipm ent/Pressu re gaug es A v oltage should be displayed f
o r "S upply v o lt ag e". Eac h control modul e will sho w it s o w n vo lt ag e va lu e. Use the " A ct iv at e" b u tt on t o pr essuri se t h e brak e cha m be r using S cania Di agnos. S et t h e pre ssur e with t h e "S et pre ssure " slid er . 2.5 bar 15 b a r 22 Cho o se "T ak e r eadi ng" t o p ressuri se t h e c ontr o l modul e wit h the b rak e pe dal. Depr essing t h e bra k e pe dal will se nd a ir ful ly pneum at ica lly t o the bra k e cha m be r, bac kup pressure . The re gulated pre ssur e i s sho w n at "P re ssure sensor". T est conne ction 5, fr ont ax le T est conne ction 5, r ear axle Test stage 14
Test m easu re L imit valu es C ause of f a u lt / act io n Suppl y voltage 20.0 - 29.0 V If the value i s t oo low, the fault will be found in t h e co ntr o l module or the c ables. Pressure set in Diagnos/P re ss ur e gauge rea d ing + 0.25 bar Pressure via bra k e peda l/ Pressure rea d ing i n Dia gnos + 0.40 bar T est conn ec tion (bar) 5 - Connect 2.5 bar pre ss u re gauges to
the test connec
tions on the re le vant axle . - Sele ct "Activate" in S cania Diagnos. - Set the de si re d pre ssur e via Scania Di agnos i n 4 steps ac co rding t o point 14 on t h e repor t. Maximum permitt ed deviation: +/-0.25 bar . If the two va lu es are not the sa m e, there m ay be a f ault i n the c ontrol module, its connec
tions or in the ele
ctric a
nd air lin
es
to
and from the control module.
- T h en compar e the pre ss u re setting wit h the r ea d ing on ea ch pressure gauge. - Change to 15 ba r pre ss u re gauge s. - Sele ct "Take r eading" in S cania Diagnos. - D epre ss the b rake pe dal to 1, 3 and 6 b ar o n the pressure ga uge. Pe rmitte d de via tion be twee n pres sure se
nsor and pre
ssure gauge : + /-0.4 ba r. The highe r pe rmitt ed de via tion is d u e to the low pr ecision of the 15 bar pressure gauges. - Compar e the value a t " P re ss ur
e sensor" in the Diagnostic
w indow w ith the pr essure ga uge. Test stage 14
15
. T
esting trailer re
la
y v
a
lv
e
IMPO R T ANT! This te st i s not v ali d f o r v ehicles with EB S 2.2 with electr o n ic t railer c ont ro l module TCM. Note : Whe n m easuring in cr ea si ng pr es sur e you may o n ly d ep re ss the br a k e pe da l o r kee p i t s til l. If t h e brak e pedal is re le ased w h en measur ing incre asing pressure , t he test result wil
l be i n co rre ct. Whe n m easuring fallin g pr es sur e you may on ly r elease t h e b rak e p ed a l or k ee p it still . If the br ak e pe dal is de presse d w h en measur ing falli ng pre ssure , the te st re sult will be in correc t. Eq ui pme n t/ Pr essur e gau ges 2.5 bar 15 b a r 2 -T est conne cti on 3 T est connec ti on 8 Test stage 15
Test m easu re T est connect io n (bar) C au se of fau lt / ac tion 38 - Connec t t h e pressure
gauges to test conne
cti ons 3 a nd 8. - Bra k e in 5 steps acc ording to poi nt 15 on the re port. Me asure t h e deviation betwee n t est connec tions 3 and 8. Ma ke a note in the r eport. Se e t h e r ead in g s in T es tin g th e EB S brake syst em , Repor t, main group 10. The pressure
level set at the f
actory a t 0.3 b ar should nor m all y not be c h
anged. For more
i n fo rmation on se ttings, see ma in gr oup 10 Tr ailer br ake c ir cuits, Components. If pr essure at test c o n n ec tion 8 r ise s or drops in st ep s, the tr ailer re
lay valve is binding and may soon cause
pr
obl
em
s.
16
. Chec
k
ing
re
gulate
d pres
sure and bac
k
up pr
ess
ur
e fr
om
e
le
c
tr
onic
tr
aile
r
co
ntr
o
l mo
du
le
, TCM-EB
S
2
.2
Eq ui pme n t/ Pr essur e gau ges A v oltage should be displayed f
o r "S upply v o lt ag e". Eac h control modul e will sho w it s o w n vo lt ag e va lu e.
Use the "Ac
ti v at e" b u tt on to pressurise the trailer bra k e c h amber using Sca n ia Diagnos. S et the press u re with t h e "S et pre ssure " slide r. 2.5 bar 15 b a r 11 Cho o se "T ak e r eadi ng" t o p ressuri se t h e c ontr o l modul e wit h the b rak e pe dal. Depr essing t h e bra k e pe dal will se nd a ir ful ly pneum at ica lly t o the trailer brak e connec tor . T est conne ction 8 Test stage 16
Test m easu re L imit values C au se of faul t / ac tion Suppl y voltage 20.0 - 29.0 V If t h e va lu e is too lo w , the fa u lt wil l be found in t h e control m odule or t h e ca bl es . Pressure set in Diagnos/P re ss ur e gauge rea d ing + /- 0.25 ba r Pressure via bra k e peda l/ Pressure rea d ing i n Dia gnos +/- 0.40 ba r T est conn ec tion (ba r) 8 - Connec t a 2.5 bar pr essure g
auge to the trailer
brake connection 8 . - Set the de si re d pre ssur e via Scania Di agnos i n 4 steps ac co rding t o point 16 on t h e repor t. Maxi mum per m itted deviat ion: +/-0.25 bar. If the two valu es a re not the same , the re m ay be a fa ult in the control mo dule , i ts conne ctions or i n the el ectric
and air lines to and fr
om t h e control module. - The n compa re the pressure se tting w
ith the rea
d ing on t h e pr essure ga uge. - Change to a 15 bar pr essure ga
uge on the tra
ile r bra k e connection 8 . - Sele ct "Take r eading" in S cania Diagnos. - D epre ss the b rake pe dal to 1, 3 and 6 b ar o n the pressure ga uge. Pe rm itte d dev iat ion bet w ee n pressure se nsor a nd pre ssure gauge : + /-0.4 bar. The highe r pe rmitt ed de viation
is due to the low pre
cision of the 15 bar pr essure ga uges. - Compar e the value a t " P re ss ur
e sensor" in the Diagnostic
w indow w ith the pr essure ga uge. - Ma ke a note i n the r eport, point 1 6 . Test stage 16
17.
T
estin
g th
e
trail
e
r rela
y
v
a
lve/trai
ler
co
ntr
o
l
mo
du
le di
sc
h
a
rg
e fu
nctio
n
IMPO R T ANT! Mak e s u re the star te r k ey is in dri v e pos ition, +15V . Equi p m ent/Pressure gaug es 2.5 bar 15 b a r --1 BSI c onn ec tor T est conne cti on 13 with i n -hous e m anuf ac tu re d tool s for ve hi cl es wi th D uo-Matic coupling .Example of test connec
ti on 13 and in-house manuf ac tur ed tools for ve hicles wi th ISO coupli n g . Test stage 17
T es t m ea sur e T es t co nn ect io n (bar) Cau se of fault / action 13 - Ma ke a tool as de sc ribed in In-house manuf ac tur ed tool s. - Plac e choc ks in f ront o
f and behind the whe
els. - R ele ase t h e pa rki ng brake . - Connec t t h e t ool a nd pressure
gauge to test connec
ti
on 13.
- Char
ge the system with air. The pr
essure ga
uge should now show full
supply pre ss u re . - Quickly depr
ess the bra
k
e pe
dal fully. The
suppl y pr essure shoul d dr op to le ss than 1.5 ba r in maxim u m two sec onds . < 1.5 If the value is i n correc t, th e tra ile r re la y val v e m u st be r eplac ed. Test stage 17
18.
Chec
kin
g
co
mm
un
icat
ion
wi
th t
railer equ
ipp
ed
wi
th
EBS
IMPO R T ANT! The v ehicle m u st be stationar y dur in g the t est ! • The sl ider control ca n be used to che ck th at t h e C AN si gnal s ar e re achi ng t h e trai ler EBS cont rol unit. Use the slide r cont ro l to go v er n t h e trailer c ontrol module. Test m easu re C aus e of fault / action - Connec t a pre ssur e gauge t o one of the tra iler brake ch amber s.- Regulate the pre
ssur e from one of t h e cont ro l modules using the slide r. The re gula te d pressure is li mite d in ti me. It wil l be re se t to 0 b ar afte r five min utes. Note tha t this func tion ma y se t faul t code s in t h e tra ile r c ontrol uni t. This is due to the elec
tronic and pne
um at ic si gna l to the tra il er not corr esponding w ith e ach other . Test stage 18
