ACURA NSX 1991 Service Repair Manual

Diagnostic Trouble Code (DTC):

1. Stop the engine.

2. Disconnect the service check connector from the connector cover located under the glove box.

Connect the two terminals of the service check connector with a jumper wire.

3. Turn the ignition switch on, but do not start the engine.

4. Record the blinking frequency of the ABS indicator light.

The blinking frequency indicates the diagnostic trouble code (DTC).

CAUTION: Before starting the engine, disconnect the jumper wire from the service check connector, or else the

Malfunction Indicator Lamp (MIL) will stay on with the engine running.

NOTE:

• The ABS control unit can indicate three DTCs (one, two or three problems).

• If the ABS indicator light does not light, see Troubleshooting of ABS Indicator Light Circuit page 19-44.

• If you miscount the blinking frequency, turn the ignition switch off, then turn on to blink the ABS indicator light

again.

• After the repair is completed, disconnect the ABS 2,3 (20A) fuse for at least three seconds to erase the ABS

control unit's memory. Then turn the ignition key on again and recheck.

• The memory is erased if the connector is disconnected from the ABS control unit or the ABS control unit is re-

moved from the body.

• After recording the main and sub-code (if applicable), refer to the Symptom-to-System Chart.ProCarManuals.com

Troubleshooting
Symptom-to-Syste m Char t
19-47
19-5 0
19-7 1
19-71
19-5 1
19-5 2
19-5 3 19-7
1
19-5 7
19-5
5
19-5 9
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Hydraulic Syste m
Hydrauli c Connection s
CAUTION: D o no t spil l brak e flui d o n th e car ; i t ma y damag e th e paint ; i f brak e flui d doe s contac t th e paint , was h it of f
immediatel y wit h water .
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Hydraulic Syste m
Relievin g Accumulator/Lin e Pressur e
1. Drai n th e brak e flui d fro m th e maste r cylinde r an d modulato r reservoi r thoroughly .
2. Remov e th e re d ca p fro m th e bleede r o n th e to p o f th e powe r unit .
3. Instal l th e specia l too l o n th e bleede r screw , an d tur n it ou t slowl y 90 ° t o collec t high-pressur e flui d int o reservoir .
Turn th e specia l too l ou t on e complet e tur n t o drai n th e brak e flui d thoroughly .
4 . Retighte n th e bleede r scre w an d discar d th e fluid .
5 . Reinstal l th e re d cap .
BLEEDE R T-WRENC H07HAA-SG0010 0or07HAA-SG0010 1
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Modulator/Solenoid Uni t
Index/Torqu e
CAUTION:
• D o no t damag e th e brak e pipe s whe n removin g th e spar e tir e an d modulator/solenoi d unit .
• D o no t spil l brak e flui d o n th e car ; i t ma y damag e th e paint ; i f brak e flui d doe s contac t th e paint , was h it of f immediate -
l y wit h water .
MODULATOR/SOLENOI D UNI TSolenoi d Lea k Test ,page 19-6 4Solenoi d Flushing ,page 19-6 5
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Modulator/Solenoid Uni t
Solenoi d Lea k Tes t
1. Disconnec t th e 6- P inspectio n connecto r (PNK )
fro m th e connecto r cove r locate d unde r th e glov e
box, an d connec t th e 6- P inspectio n connecto r t o
th e AL B checker .
CONNECTO RCOVER
ALB CHECKE R07HAJ-SG0010BSe e pag e 19-2 fo r othe rapplicabl e checkers .
6-P INSPECTIO NCONNECTO R
CAUTION: Plac e th e vehicl e o n leve l groun d wit h
th e wheel s blocked . Pu t th e transmissio n in neutra l
for manua l transmissio n models , o r i n fo r auto -
mati c transmissio n models .
2. Remov e th e modulato r reservoi r filter , the n fil l th e
modulato r reservoi r t o th e MA X leve l line .
NOTE : D o no t reus e aerate d brak e flui d tha t ha s
bee n ble d fro m th e powe r unit .
3. Blee d high-pressur e flui d fro m th e maintenanc e
bleeder with the specia l tool .
BLEEDE R T-WRENC H07HAA-SG0010 1or07HA A-SG0010 0
SOLENOI D UNI T
ACCUMULATOR /PRESSURE SWITC HPOWERUNIT
MAINTENANC EBLEEDER8 x 1.2 5 mm9 N- m (0. 9 kg-m ,6.5 Ib-ft )
4. Star t th e engin e an d releas e th e parkin g brake .
5 . Tur n th e Mod e Selecto r t o 1 , an d pres s th e Star t
Tes t button .
6 . Whil e th e pum p i s running , plac e you r finge r ove r
th e to p o f th e solenoi d retur n tub e in th e modulato r
reservoir.
SOLENOI D RETUR NTUBEFeel fo r brak efluid here .
• I f yo u ca n fee l brak e flui d comin g fro m th e retur n
tube , on e o f th e solenoid s i s leaking . G o t o ste p
7.
• I f yo u can' t fee l brak e flui d comin g fro m th e
retur n tube , th e solenoid s ar e OK .
Reinstal l th e modulato r reservoi r filte r an d refil l
th e reservoi r t o th e MA X leve l line .
7 . Blee d high-pressur e flui d fro m th e maintenanc e
bleede r wit h th e specia l tool .
8 . Repea t step s 5 throug h 7 at mode s 2 to 5 wit h th e
AL B checker .
• I f th e solenoi d leakag e ha s stopped , reinstal l th e
modulato r reservoi r filte r an d refil l th e reservoi r
t o th e MA X leve l line .
• I f yo u ca n fee l brak e flui d comin g fro m th e retur n
tube , on e o f th e solenoid s i s leaking . G o t o
Solenoi d Flushing .
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Solenoid Flushin g
1. Remov e th e moto r rela y fro m th e under-hoo d
fuse/rela y box . (Location : se e pag e 19-40 )
2 . Instal l th e specia l too l int o th e tw o moto r rela y cavi -
tie s i n th e rela y box .
AUXILIAR Y
WINDO W SWITC H
07KAZ-001000 A
MOTOR RELA Y
UNDER-HOO DFUSE/RELAYBOX
3. Disconnec t th e fou r modulato r solenoi d connec -
tors .
4 . Blee d an y high-pressur e flui d fro m th e maintenanc e
bleeder wit h th e specia l tool , the n retighte n th e
bleeder .
SOLENOI D UNI T
BLEEDE R T-WRENC H07HAA - SG0010 1or 07HA A-SG0010 0
ACCUMULATOR /
PRESSUR E SWITC HPOWERUNIT
MAINTENANC EBLEEDER8 x 1.2 5 mm9 N- m (0. 9 kg-m ,6.5 Ib-ft )
5. Connec t th e RE D termina l fro m on e solenoi d con -
necto r t o th e batter y positiv e (+ ) termina l wit h a
remot e starte r switch . Connec t th e BL K termina l
fro m th e sam e solenoi d t o th e batter y negativ e (- )
termina l wit h a jumpe r lea d a s shown .
SOLENOI D CONNECTOR S
FRONT-RIGH T REAR-LEF T REAR-RIGH T
FRONT-RIGHT
REMOT ESTARTE RSWITCH
6. Pres s th e auxiliar y windo w switc h t o ru n th e pump .
Afte r th e pum p ha s ru n fo r abou t fiv e seconds ,
pres s an d releas e th e remot e starte r switc h thre e o r
fou r time s t o ope n an d clos e th e solenoid . Continu e
runnin g th e pum p fo r abou t 3 0 seconds , the n
releas e th e auxiliar y windo w switc h an d ope n an d
clos e th e solenoi d anothe r thre e o r fou r times .
7. Repea t step s 4- 6 fo r th e othe r thre e solenoids .
8 . Reconnec t th e solenoid s an d th e pum p relay .
9 . Connec t th e AL B Checke r an d tur n th e Mod e Selec -
to r t o "1" . Star t th e engin e an d releas e th e parkin g
brake . Pus h th e Star t Tes t butto n o n th e AL B
Checker .
10. Whil e th e pum p i s running , plac e you r finge r ove r
th e to p o f th e solenoi d retur n tub e in th e modulato r
reservoi r an d chec k fo r leaks .
• I f a solenoi d i s stil l leaking , replac e th e
modulator/solenoi d
unit.
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Power Uni t
Torque/Inspectio n
CAUTION:
• D o no t attemp t t o disassembl e th e powe r uni t ex -
cep t fo r thos e component s show n in thi s illustration .
• D o no t spil l brak e flui d o n th e car ; i t ma y damag e th e
paint ; i f brak e flui d doe s contac t th e paint , was h i t
of f immediatel y wit h water .
• T o preven t spills , cove r th e hos e joint s wit h rag s o r
sho p towels .
• Clea n al l part s i n brak e flui d an d ai r dry ; blo w ou t al l
passage s wit h compresse d air . Befor
e reassembling , chec k tha t al l part s ar e fre e o f
dus t an d othe r foreig n particles .
Replac e part s wit h ne w one s wheneve r specifie d t o
do so .
Mak e sur e n o dir t o r othe r foreig n matte r i s allowe d
t o contaminat e th e brak e fluid .
D o no t reus e th e draine d fluid .
Us e onl y clea n DO T 3 o r 4 brak e fluid .
BANJ O BOL T(To modulator )35 N- m (3. 5 kg-m , 2 5 Ib-ft )
SEALIN GWASHER SReplaceBANJO BOL T35 N- m (3. 5 kg-m , 2 5 Ib-ft )
MAINTENANC EBLEEDER9 N- m (0. 9 kg-m , 6. 5 Ib-ft )
POWE R UNI TDo no t disassembl e
PUMP BRACKE T
6 m m FLANG E BOL T10 N- m (1. 0 kg-m , 7 Ib-ft )
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Accumulator/Pressure Switch

Index/Torque
CAUTION: Do not spill brake fluid on the car; it may damage the
paint; if brake fluid does contact the paint, wash it
off immediately with water.
To prevent spills, cover the hose jpints with rags or shop towels.
Clean all parts in brake fluid and air dry; blow out all passages with compressed air.
Before reassembling, check that all parts are free of
dust and other foreign particles. Replace parts with new ones whenever specified to

do so.

Before disassembling the accumulator unit, bleed the
high-pressure brake fluid out from the system using
the Bleeder T-wrench (see page 19-62('91-'92)('93-'96)

the Bleeder

*: CORROSION RESISTANT BOLT

Make sure no dirt or other foreign matter is allowed
to contaminate the brake fluid. Do not reuse the drained fluid.
Use only clean DOT 3 or 4 brake fluid.

NOTE: Replace the 0-ring with a new one before

reassembly. The accumulator contains high-pressure
nitrogen gas, do not puncture, expose to flame, or at-
tempt to disassemble the accumulator or it may ex-
plode; severe personal injury may result.

19 N·m
(1.9 kg-m,

14 Ib-ft)

PRESSURE SWITCH

SEALING WASHERS

Replace.

BANJO BOLT

35 N·m (3.5 kg-m, 26 Ib-ft)
6 x 1.0 mm

9 N·m
(0.9 kg-m,7 Ib-ft)
ACCUMULATOR

Disposal, page 19-68
* 6 x 1.0 mm

10 N·m (1.0 kg-m, 7 Ib-ft)

O-RING

Replace.
PRESSURE SWITCH

JOINT
6 x 1.0 mm

10 N·m
(1.0 kg-m,

7 Ib-ft)ProCarManuals.com

Accumulator/Pressure Switc h
Accumulator/Pressur e
Switc h Remova l
1. Drai n th e hig h pressur e brak e flui d fro m th e powe r
unit (se e pag e 19-62 ).
2 . Remov e thre e 6 m m flang e bolts , the n remov e th e
accumulato r fro m th e pressur e switc h joint .
6 x 1. 0 m m10 N- m (1. 0 kg-m , 7 Ib-ft )
PRESSUR E SWITC HJOINT
ACCUMULATO R
Accumulator Disposa l
The accumulato r contain s high-pressur e
nitroge n gas , d o no t puncture , expos e t o flame , o r at -
temp t t o disassembl e th e accumulato r o r i t ma y ex -
plode ; sever e persona l injur y ma y result .
1 . Secur e th e accumulato r i n a vis e s o tha t th e relie f
plug point s straigh t up .
2. Slowl y tur n th e plu g 3-1/ 2 turns , the n wai t 3 minute s
for al l pressur e t o escape .
3. Remov e th e plu g completely , an d dispos e o f th e ac -
cumulato r unit .
RELIE F PLU G
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