ACURA NSX 1997 Service Repair Manual

Pulsed Secondary Air Injection System Description

The air pump system is designed to advance the activation of the catalyst and to reduce the hydrocarbons (HC), carbon

monoxide (CO), and oxides of nitrogen (NOx) in the exhaust gas.

The system operates after the engine starts under the following conditions:

• The engine coolant temperature is between 0°C and 70°C (32°F and 158°F).

• The difference in engine coolant temperature is more than 20°C (36°F) between the time when the engine is started and

when the engine is stopped in the previous driving cycle.

AIR CONTROL

SOLENOID VALVE

AIR CONTROL

VALVE

WHT

AIR PUMP

RELAY
From

No. 5 BACK-UP LIGHTS

ALTERNATOR

TURN SIGNALS

(15 A) FUSE

From

AIR PUMP

(60 A) FUSE

AIR CONTROL VALVE

VACUUM TANK

AIR CONTROL VALVE

CHECK VALVE

When the engine is started, the air pump runs and sends fresh air to the air control valve. The air control valve allows the

fresh air to flow to the exhaust ports when its diaphragm is pulled by engine vacuum. It gets engine vacuum from the air

control solenoid, which is activated by the ECM. Once the fresh air flows into the exhaust ports near the exhaust valves, it

reacts with the exhaust gases, raising exhaust gas temperatures. This promotes faster warm-up of the catalytic converter.

The system operates for a maximum of 60 seconds, but the running time shortens in relation to the engine coolant tem-

perature and the intake air temperature. When the system is not operating, the air control solenoid and the air control

valve are closed to prevent exhaust gases from entering the system.
AIR PUMP

ELECTRICAL

CURRENT

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Mainshaft Assembl y
Index
NOTE : Th e 3rd/4t h an d 5th/6t h synchr o hub s ar e installe d wit h a press .
Prio r t o reassembling , clea n al l th e part s i n solvent , dr y them , an d appl y lubrican t t o an y contac t surfaces .
Th e 3rd/4t h an d 5th/6t h synchr o hubs , however , shoul d b e installe d wit h a pres s befor e lubricatin g them .
INNER SYNCHR O RIN G
SYNCHR O CON E
OUTE R SYNCHR O RIN G
SYNCHR O SPRIN G
3RD/4T H SYNCHR O SLEEV E
3RD/4T H SYNCHR O HU B
SYNCHR O SPRIN G
OUTE R SYNCHR O RIN G
SYNCHR O CON E
INNE R SYNCHR O RIN G
3RD GEA R
42 x 47 x 30. 5 mmNEEDL E BEARING S
Inspec t fo r wea r an d operation .
MAINSHAF T
BALL BEARIN GInspect fo r wea r an d operation .
ANGULAR BAL L BEARIN G
Chec k fo r wea r an d operation .
Note th e directio n o f installation .
DISTANCE COLLA R
42 x 47 x 22 m mNEEDL E BEARIN G
Inspec t fo r wea r an d operation .
6TH GEA R
INNER SYNCHR O RIN G
SYNCHR O CON E
OUTE R SYNCHR O RIN G
SYNCHR O SPRIN G
5TH/6T H SYNCHR O SLEEV E
5TH/6T H SYNCHR O HU B
SYNCHR O SPRIN G
OUTER SYNCHR O RIN G
SYNCHR O CON E
INNE R SYNCHR O RIN G
5T H GEA R
42 x 47 x 26. 5 mmNEEDL E BEARIN GInspect fo r wea r an d operation .
SPACER COLLA R
42 x 47 x 26. 5 mmNEEDL E BEARIN GInspect fo r wea r an d operation .
4TH GEA R
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Clearance Inspectio n
1. Measur e th e clearanc e betwee n th e space r colla r
an d 5t h gear .
Standard : 0.0 6 - 0.1 9 m m
(0.00 2 - 0.00 7 in )
Servic e Limit : 0. 3 m m (0.01 2 in )
2 . I f th e clearanc e exceed s th e servic e limit , measur e
distance o n th e space r collar .
Standard : 26.5 3 - 26.5 8 m m
(1.04 4 - 1.04 6 in )
Servic e Limit : 26.5 1 m m (1.04 4 in )
3. I f distanc e i s les s tha n th e servic e limit , replac e
th e space r colla r wit h a ne w one .
If distanc e i s withi n th e servic e limit , measur e
thickness o f 5t h gear .
Standard : 26.3 9 - 26.4 7 m m
(1.03 9 - 1.04 2 in )
Servic e Limit : 26.3 0 m m (1.03 5 in )
I f th e thicknes s o f 5t h gea r i s les s tha n th e servic e
limit, replac e 5t h gea r wit h a ne w one .
If th e thicknes s o f 5t h gea r i s withi n th e servic e
limit, replac e th e 5th/6t h synchr o hu b wit h a ne w
one .
4. Measur e th e clearanc e betwee n th e distanc e colla r
an d 6t h gear .
Standard : 0.0 6 - 0.1 9 m m
(0.00 2 - 0.00 7 in )
Servic e Limit : 0. 3 m m (0.01 2 in )
5 . I f th e clearanc e exceed s th e servic e limit , measur e
distance o n th e distanc e collar .
Standard : 22.0 3 - 22.0 8 m m
(0.86 7 - 0.86 9 in )
Servic e Limit : 22.0 1 m m (0.86 7 in )
6. I f distanc e i s les s tha n th e servic e limit , replac e
the distanc e colla r wit h a ne w one .
If distanc e i s withi n th e servic e limit , measur e
thickness o f 5t h gear .
Standard : 21.8 9 - 21.9 7 m m
(0.86 2 - 0.86 5 in )
Servic e Limit : 21.8 0 m m (0.85 8 in )
I f th e thicknes s o f 6t h gea r i s les s tha n th e servic e
limit, replac e 6t h gea r wit h a ne w one .
If th e thicknes s o f 6t h gea r i s withi n th e servic e
limit, replac e th e 5th/6t h synchr o hu b wit h a ne w
one .
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Shift Loc k Releas e Cove r
Installatio n ——————————
Take th e "SHIF T LOC K RELEASE " cove r of f th e A/ T
gea r positio n indicato r panel , an d pee l of f th e
remainin g adhesive .
Clea n th e indicato r pane l thoroughl y wit h a spong e
dampene d in alcohol .
SHIFT LOC K RELEAS ECOVER
A/ T GEA R POSITIO N
INDICATO R PANE L Pee
l of f th e
remainin gadhesive .
2. Remov e th e peel-of f backin g fro m th e ne w cover .
3 . Instal l th e cove r b y alignin g th e righ t en d wit h th e
hollo w egde , an d pres s th e cove r wit h you r finger s
to secur e it .
Mak e sur e th e ne w cove r doe s no t mov e o r i s no t
take n off .
COVE R
HOLLO W EDG E
KEYHOL E
4. Mak e sur e th e slo t o n th e lef t en d o f th e cove r i s
exposed . I f th e slo t i s covered , remov e th e cove r
an d reinstal l i t properly .
SLOT COVE
R
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Troubleshooting Precaution s
EPS Indicato r Ligh t
Unde r norma l conditions , th e EP S indicato r i n th e gaug e assembl y come s o n whe n th e ignitio n switc h is turne d t o th e O N
(II ) position , the n goe s of f afte r th e engin e i s started . Thi s indicate s tha t th e bul b an d it s circuit s ar e operatin g correctly . I f
ther e i s an y troubl e i n th e system , th e EP S indicato r turn s o n durin g driving , an d th e powe r steerin g assis t i s turne d off .
Whe n th e EP S indicato r come s on , th e contro l uni t memorize s th e DTC . I n thi s case , th e contro l uni t doe s no t activat e th e
EP S syste m afte r th e engin e start s agai n bu t i t keep s th e EP S indicato r on .
Whe n a proble m is detected , th e EP S indicato r come s on . Unde r som e conditio n th e indicato r stay s o n unti l th e ignitio n switc h
i s turne d OFF . Unde r othe r conditions , however , th e indicato r goe s of f automaticall y whe n th e syste m return s to normal .
Fo r DTC s 2 3 an d 31 , th e indicato r goe s of f automaticall y whe n th e syste m return s t o normal . Fo r al l othe r codes , th e indicato r
stay s in unti l th e ignitio n switc h is turne d OFF .
Fo r DTC s 2 4 an d 25 , th e EP S indicato r goe s of f whe n th e syste m is O K afte r th e ignitio n switc h is turne d fro m OF F to O N
(ID .
Diagnosti c Troubl e Cod e (DTC )
• Th e lowes t DT C is indicate d first .
• Th e DTC s continu e blinkin g unti l th e ignitio n switc h i s turne d off .
• Th e DTC s ar e erase d fro m th e contro l uni t whe n th e EP S contro l uni t VB U powe r suppl y o r connecto r i s disconnected .
• Th e EP S syste m ca n b e rese t an d th e contro l unit' s memor y ca n b e erase d b y disconnectin g th e CLOC K (7. 5 A ) fus e fo r
mor e tha n te n second s (excep t DTC s 2 4 an d 25) .
Self-diagnosis :
The CP U (centra l processin g unit ) control s th e followin g whe n it detect s a proble m durin g self-diagnosis :
1 . Turn s th e EP S indicato r O N to aler t th e driver .
2 . Powe r assis t stops , an d norma l manua l steerin g operatio n resume s (excep t DT C 33) .
3 . Th e EP S contro l uni t memorize s th e diagnosti c troubl e cod e (DTC) .
4 . Afte r th e DT C is store d in th e contro l unit , th e CP U stop s self-diagnosis .
Troubleshooting :
• Befor e startin g th e troubleshooting , clea r th e DT C b y disconnectin g th e CLOC K (7. 5 A ) fus e fo r te n second s o r more ,
an d test-driv e th e vehicle . Chec k tha t th e sympto m o f th e troubl e appear s again , an d the n troubleshoot . I f th e proble m
i s a n intermitten t problem , th e syste m doe s no t becom e activ e afte r th e engin e start s eve n thoug h th e proble m is
solved .
• Whe n bot h EP S indicato r an d A/ T "D " indicato r com e on , perfor m th e A/ T troubleshootin g first .
• Whe n th e customer' s reporte d proble m canno t b e verifie d i n th e car , as k th e custome r abou t th e condition s whe n th e
EP S indicato r cam e ON , the n test-driv e th e ca r unde r thos e conditions , i f possible . I f th e EP S indicato r doe s no t com e
O N durin g th e test , chec k fo r loos e connection s o r poo r contact s a t th e connector s b y wigglin g th e harness , etc .
• Th e connecto r termina l number s ar e viewe d fro m th e wir e sid e fo r th e femal e terminal s an d fro m th e termina l sid e fo r
th e mal e terminals .
• Afte r th e repair , test-driv e th e ca r an d chec k tha t th e EP S indicato r doe s no t com e O N agai n durin g th e test . (Refe r t o
th e Symptom-to-Syste m Char t fo r diagnosti c period. )
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Symptom-to-System Char t
Diagnosti c Troubl e Cod e (DTC )
• Initia l diagnosis : Performe d righ t afte r th e engin e start s unti l th e EP S indicato r goe s off .
• Regula r diagnosis : Continuousl y performe d (unde r som e conditions ) afte r th e EP S indicato r goe s of f unti l th e engin e stops .
• Individua l part/syste m diagnosis: Diagnoses a specifi c part/syste m unde r it s operatin g conditions .
• CPU : Centra l Processin g Unit .
17-25
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Component Location s
SERVICE CHEC KCONNECTO R (2P ) RIGHT-REA
R WHEE L SENSO R
UNDER-HOO D
FUSE/RELA Y BO X
RIGHT-FRON TWHEEL SENSO R
LEFT-REA RWHEEL SENSO R
UNDER-DAS H FUS E BO X
AB S MODULATO R
CONTROL UNI T
GAUG E ASSEMBL Y
AB S INDICATO R
LEFT-FRON TWHEEL SENSO R
UNDER-HOO D FUSE/RELA Y BO X
ABS(30 A ) FUS E
IG S W (A )(50 A ) FUS E BRAK
E LIGHTS/HOR N
(2 0 A ) FUS E
UNDER-DAS H FUS E BO X
ABS 1 , 4(2 0 A ) FUS E
BACK-U P LIGHT S
(ISA ) FUS E
HEATE R CONTRO L
(15 A) FUSE
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System Descriptio n
Features/Constructio n
When th e brak e peda l i s presse d durin g driving , th e wheel s ca n loc k befor e th e vehicl e come s t o a stop . I n suc h a n event ,
th e maneuverabilit y o f th e vehicl e i s reduce d i f th e fron t wheel s ar e locked , an d th e stabilit y o f th e vehicl e i s reduce d i f th e
rea r wheel s ar e locked , creatin g a n extremel y unstabl e condition . Th e AB S precisel y control s th e sli p rat e o f th e wheel s t o
ensur e maximu m gri p forc e fro m th e tires , an d i t thereb y ensure s maneuverabilit y an d stabilit y o f th e vehicle . Th e AB S
calculate s th e sli p rat e o f th e wheel s base d o n th e vehicl e spee d an d th e whee l speed , the n it control s th e brak e flui d pres -
sur e t o attai n th e targe t sli p rate .
WHEE L
SENSO R
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*1: WithTC S
Terminal sid e o f femal e terminal s
ABS CONTRO L UNI T 25 P CONNECTO R
ABS Contro l Uni t Termina l Arrangemen t
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*1: WithTCSProCarManuals.com