1997 ACURA NSX alternator

Exhaust Gas Recirculation (EGR) System

The EGR system is designed to reduce oxides of nitrogen emissions (NOx) by recirculating exhaust gas through the EGR

valve and the intake manifold into the combustion chambers. It is composed of the EGR valve, EGR vacuum control valve,

EGR control solenoid valve, ECM and various sensors.

The ECM contains memories for ideal EGR valve lifts for varying operating conditions. The EGR valve lift sensor detects

the amount of EGR valve lift and sends the information to the ECM. The ECM then compares it with the ideal EGR valve lift

which is determined by signals sent from the other sensors. If there is any difference between the two, the ECM varies cur-

rent to the EGR control solenoid valve to regulate vacuum applied to the EGR valve.

EGR

VALVE

LIFT

SENSOR
INTAKE

MANIFOLD

EGR

CONTROL

SOLENOID

VALVE
To No. 5 BACK-UP

LIGHTS ALTERNATOR

TURN SIGNALS

(15 A) FUSE

-EGR

VACUUM

CONTROL

VALVE

(cont'd)
EGR

VALVE

VARIOUS

SENSORSProCarManuals.com

Evaporative Emission (EVAP) Controls

Description

The evaporative emission controls are designed to minimize the amount of fuel vapor escaping to the atmosphere. The

system consists of the following components:

A. Evaporative Emission (EVAP) Control Canister

An EVAP control canister is used for the temporary storage of fuel vapor until the fuel vapor can be purged from the

EVAP control canister into the engine and burned.

B. Vapor Purge Control System

EVAP control canister purging is accomplished by drawing fresh air through the EVAP control canister and into a port

on the throttle body. The purging vacuum is controlled by the EVAP purge control solenoid valve.

C. Fuel Tank Vapor Control System

When fuel vapor pressure in the fuel tank is higher than the set value of the EVAP two way valve, the valve opens and

regulates the flow of fuel vapor to the EVAP control canister.

From No. 5 BACK-UP

LIGHTS ALTERNATOR

TURN SIGNALS (15 A)

FUSE

FUEL TANK

EVAP VALVE
EVAP

BYPASS

SOLENOID

VALVE
VARIOUS

SENSORS

EVAP CONTROL

CANISTER

VENT SHUT VALVE

FUEL

TANK

PRESSURE

SENSOR
EVAP

TWO WAY

VALVE
EVAP CONTROL

CANISTER
EVAP PURGE

CONTROL

SOLENOID VALVE

(cont'd)
FUEL FILL

CAPProCarManuals.com

Troubleshooting

Tips and Precautions

Before Troubleshooting

Check applicable fuses in the appropriate fuse box.

Check the battery for damage, state of charge, and

clean and tight connections.

Check the alternator belt tension.

CAUTION:

Do not quick-charge a battery unless the battery

ground cable has been disconnected.

Otherwise you will damage the alternator

diodes.

Do not attempt to crank the engine with the bat-

tery ground cable loosely connected or you will

severely damage the wiring.

Handling Connectors

Make sure the connectors are clean and have no loose

wire terminals.

Make sure multiple cavity connectors are packed with

grease (except watertight connectors).

All connectors have push-down release type locks.

LOCKING TAB

Some connectors have a clip on their side used to at-

tach them to a mount bracket on the body or on

another component. This clip has a pull type lock.

Some mounted connectors cannot be disconnected

unless you first release the lock and remove the con-

nector from its bracket.

(21

LOCKING'

PAWL ON

OTHER

HALF OF

CONNECTOR
Pull to

disengage

BRACKET
Never try to disconnect connectors by pulling on their

wires; pull on the connector halves instead.

Always reinstall plastic covers.

Before connecting connectors, make sure the ter-

minals are in place and not bent.

BENT TERMINAL

Check for loose retainer and rubber seals.

RETAINER
RUBBER SEAL RETAINER

The backs of some connectors are packed with

grease. Add grease if needed. If the grease is con-

taminated, replace it.

(cont'd)ProCarManuals.com

Charging Syste m
Troubleshootin g
If th e chargin g syste m ligh t i s on , o r th e batter y i s dea d o r low , tes t th e followin g item s i n th e orde r listed :
1. Batter y (se e pag e 23-68 )
2 . Chargin g Syste m Ligh t
3 . Alternator/Regulato r
Charging Syste m Ligh t Tes t
Doe s th e chargin g syste m ligh t
com e on ?
Star t th e engine .
Does th e chargin g syste m ligh tgo off ?
Turn th e ignitio n switc h off .
Disconnec t th e 4 P connecto r
fro m th e alternator .
Turn th e ignitio n switc h O N (II) .
WHT/BL U wir e i s OK ; perfor m
alternator/regulato r tes t (se e pag e
23-102 ).
(T o page 23-101 )
Chargin g syste m ligh t circui t i s
OK .
Disconnec t th e AB S contro l uni t
(C235) , EP S contro l uni t (C249) ,
an d th e integrate d contro l uni t
(C401) , a s applicable . I f th e
chargin g syste m ligh t stay s on ,
repai r th e shor t t o groun d i n th e
WHT/BL U wire .
Does th e chargin g syste m ligh tcom e on ?
Tur
n th e ignitio n switc h O N (II) .
ProCarManuals.com

(From page 23-100 )
I s th e fus e OK ?
Disconnec t th e 4 P connecto r
fro m th e alternator .
Tur n th e ignitio n switc h O N (II) .
Chec k fo r voltag e in th e YE L wir e
a t th e I G termina l o f th e 4 P con -
nector .
Is ther e batter y voltage ?
Groun d th e WHT/BL U wir e a t th e
L termina l o f th e 4 P connector .
Doe s th e chargin g syste m
light com e on ?
Perfor m alternator/regulato r tes t
(se e pag e 23-102 ). Replac
e th e fuse .
Repai r ope n in th e YE L wire .
Chec k fo r a blow n chargin g sys -
tem ligh t bulb . I f th e bul b is OK ,repai r ope n in th e WHT/BL U wire .
(cont'd )
Turn th e ignitio n switc h off .
Chec k fus e No . 2 (1 5 A) .
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Charging System

Troubleshooting (cont'd)

Alternator/Regulator Test

Use the SUN VAT-40 (or equivalent) tester.

LOAD ADJUSTER

(CARBON PILE)
FULL FIELD

LEAD (BLU)

VOLTMETER

NEGATIVE

LEAD (BLK)

INDUCTIVE

PICK-UP

(GRN)
POSITIVE

CABLE (RED)
NEGATIVE

CABLE (BLK)
VOLTMETER

POSITIVE

LEAD (RED)

1. Attach the positive tester cable and the voltmeter

positive lead to the jump start terminal in the

engine compartment fuse/relay box.

POSITIVE CABLE

VOLTMETER

POSITIVE LEAD

JUMP

START

TERMINAL

ENGINE COMPARTMENT

FUSE/RELAY BOX
2. Attach the negative tester cable and the voltmeter

negative lead to the top of the intake manifold.

VOLTMETER

NEGATIVE LEAD
NEGATIVE CABLE

NEGATIVE MARK

3. Attach the inductive pick-up to the B terminal wire

of the alternator with its arrow pointing away from

the terminal.

NOTE: The arrow must point away from the B

terminal.

INDUCTIVE PICK-UP

ARROW
ALTERNATOR

B TERMINAL

ALTERNATORProCarManuals.com

Charging Syste m
Troubleshootin g (cont'd )
(From page 23-103 )
Apply a loa d wit h th e VAT-4 0
unti l th e batter y voltag e drop s t o
betwee n 12-13. 5 V .
I s th e amperag e 8 5 A or more ?
Wit h th e engin e spee d stil l a t
2,00 0 rpm , full-fiel d th e alter -
nator .
Tur n th e ignitio n switc h off .
Disconnec t th e 4- P connecto r
fro m th e alternator .
Tur n th e ignitio n switc h O N (II) .
Chec k fo r voltag e in th e YE L wir e
a t th e I G termina l an d i n th e
WHT/GR N wir e a t th e S termina l
o f th e 4- P connector .
I s ther e batter y voltag e in bot h
wires ?
Chargin g syste m is OK .
NOTE : Attac h a prob e to th e VAT-4 0 full-fiel d tes t
lead , an d inser t th e prob e int o th e full-fiel d acces s
hole a t th e bac k o f th e alternator . Switc h th e fiel d
selecto r t o " A (Ground) " positio n momentarily , an d
chec k th e amperag e reading .
CAUTION : Th e voltag e wil l ris e quickl y whe n th e
alternato r i s full-fielded . D o no t le t i t excee d 18 V
or yo u ma y damag e th e electrica l system .FULL-FIEL D ACCES S HOL E
END COVE R
REGULATO R(Located insid e th e en d cover )
Tes t an d repai r th e alternato r
(se e pag e 23-107 ).
IG (YEL )
S (WHT/GRN )
Repair ope n in th e YE L wir e o r th eWHT/GR N wire .
Is th e alternato r outpu t 8 5 A ormore ?
Replac e th e voltag e regulator .
ProCarManuals.com

Alternator Replacemen t
1. Disconnec t th e negativ e cabl e fro m th e battery .
2 . Disconnec t th e 4 P connecto r fro m th e alternator .
3 . Remov e th e nu t an d th e BL K wir e fro m th e B
terminal .
BLK WIR ENUT 1 2 N- m(1.2 kgf-m , 9 Ibf-ft )
4P CONNECTO R
4. Remov e th e pulle y cove r fro m th e alternator .
PULLEY COVE R
5. Remov e th e nu t fro m th e adjustment-loc k bolt ,
loose n th e mountin g bol t an d th e adjustin g bolt ,
the n remov e th e bel t fro m th e pulley .
ADJUSTMENT-LOC KNUT45 N- m (4. 6 kgf-m , 3 3 Ibf-ft )
ADJUSTIN G BOL T8 N- m (0. 8 kgf-m , 5. 8 Ibf-ft )
ADJUSTMENT-LOC KBOLT
ALTERNATO RBRACKET
MOUNTIN G BOL T45 N- m (4. 6 kgf-m , 3 3 Ibf-ft )
6. Remov e th e adjustin g bolt , adjustment-loc k bol t
an d th e mountin g bolt , the n remov e th e alternato r
fro m th e bracket .
7 . Instal l th e alternato r i n th e revers e orde r o f
removal .
8. Adjus t th e alternato r bel t tensio n afte r installin g th e
alternato r (se e pag e 23-109 ).
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