ACURA NSX 1997 Service Repair Manual

NOTE: Differen t wire s wit h th e sam e colo r hav e bee n give n a numbe r suffi x t o distinguis h the m (fo r example , YEU/BLK1
an d YEL/BLK2 ar e no t th e same) .
Related to Fue l an d Emission s System .
— Connecto r wit h mal e terminal s (doubl e outline) : Vie w fro m termina l sid e
— Connecto r wit h femal e terminal s (singl e outline) : Vie w fro m wir e sid e (cont'd )
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System Description

System Connectors [Front Compartment and Under-dash] (cont'd)

UNDER-HOOD

FUSE/RELAY

BOX

SUB RELAY

BOX A

FRONT

COMPARTMENT

WIRE

HARNESS
UNDER-DASH

FUSE

BOX
SIDE

WIRE

HARNESS
FLOOR

WIRE

HARNESSProCarManuals.com

NOTE: Differen t wire s wit h th e sam e colo r hav e bee n give n a numbe r suffi x t o distinguis h the m (fo r example , YEU/BLK1
an d YEU/BLK2 ar e no t th e same) .
Related t o Fue l an d Emission s System .
— Connecto r wit h mal e terminal s (doubl e outline) : Vie w fro m termina l sid e
— Connecto r wit h femal e terminal s (singl e outline) : Vie w fro m wir e sid e
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Troubleshooting
Troubleshooting Procedure s
I. Ho w T o Begi n Troubleshootin g
Whe n th e Malfunctio n Indicato r Lam p (MIL ) ha s bee n reporte d on , o r ther e i s a driveabilit y problem , us e th e appropri -
at e procedur e belo w to diagnose and repai r th e problem .
MALFUNCTIO NINDICATORLAMP(MIL)
A. Whe n th e MI L ha s com e on :
1 . Connec t th e Hond a PG M Teste r o r a n OB D II
sca n too l t o th e 16 P Dat a Lin k Connecto r (DLC )
locate d unde r th e glov e bo x behin d a removabl e
cover .
2. Tur n th e ignitio n switc h O N (II) .
3. Chec k th e DT C an d not e it . Als o chec k an d not e
th e freez e fram e data . Refe r t o th e Diagnosti c
Troubl e Cod e Char t an d begi n troubleshooting .
NOTE:
See th e OB D I I sca n too l o r Hond a PG M
Teste r user' s manual s fo r specifi c operatin g
instructions .
Th e sca n too l o r teste r ca n rea d th e Diagnosti c Troubl e Code s (DTC) , freez e fram e data , curren t data , an d othe r
Engin e Contro l Modul e (ECM ) data .
Freez e fram e dat a indicate s th e engin e condition s whe n th e firs t malfunction , misfir e o r fue l tri m malfunctio n
was detected . I t ca n b e usefu l informatio n whe n troubleshooting .
B . Whe n th e MI L ha s no t com e on , bu t ther e i s a driveabilit y problem , refe r t o th e Sympto m Char t o n pag e 11-42 .
C . DTC s wil l b e indicate d b y th e blinkin g o f th e Malfunctio n Indicato r Lam p (MIL ) wit h th e SC S servic e connecto r con -
nected .
Connec t th e SC S servic e connecto r t o Servic e Chec k Connecto r a s shown . (Th e 2 P Servic e Chec k Connecto r i s
locate d unde r th e das h o n th e passenger' s sid e o f th e vehicle. ) Tur n th e ignitio n switc h o n (II) .
DAT A LIN K CONNECTO R (16P )SERVIC E CHEC KCONNECTO R (2P )
OBD II SCA N TOO L o r
HOND A PG M TESTE RSCS SERVIC E CONNECTO R07PAZ-001010 0
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Engine Control Module (ECM) Reset Procedure

Either of the following actions, will reset the ECM.

Using the OBD II scan tool or Honda PGM Tester to clear the ECM's memory.

NOTE: See the OBD II scan tool or Honda PGM Tester user's manuals for specific operating instructions.

Turn the ignition switch OFF. Remove the CLOCK (7.5 A) fuse from the under-hood fuse/relay box for 10 seconds.

UNDER-HOOD

FUSE/RELAY BOX
CLOCK

(7.5 A) FUSE

III. Final Procedure (this procedure must be done after any troubleshooting)

1. Remove the SCS Service Connector if it is connected. If the SCS service connector is connected and there are no

DTCs stored in the ECM, the MIL will stay on when the ignition switch is turned on.

2. Do the ECM Reset Procedure.

3. Turn the ignition switch OFF.

4. Disconnect the OBD II scan tool or Honda PGM Tester from the Data Link Connector (16P).

IV. Known-Good ECM Substitution

The ECM is part of the immobilizer system. If you substitute a known-good ECM, the ECM will have a different immo-

bilizer code. In order for the engine to start, you must rewrite the immobilizer code with the Honda PGM Tester.

(cont'd)ProCarManuals.com

Troubleshooting
Troubleshooting Procedure s (cont'd )
If th e inspectio n fo r a particula r cod e require s voltag e o r resistanc e check s a t th e EC M connectors , remov e th e bulkhea d
panels . Unbol t th e ECM . Chec k th e syste m accordin g t o th e procedur e describe d fo r th e appropriat e code(s ) liste d o n th e
followin g pages .
ECM
BULKHEA DPANELS
How to Us e th e Backprob e Set s
Connec t th e backprob e adapter s t o th e stackin g patc h cords , an d connec t th e cord s t o a multimeter . Usin g th e wir e insula -
tio n a s a guid e fo r th e contoure d ti p o f th e backprob e adapter , gentl y slid e th e ti p int o th e connecto r fro m th e wir e sid e
unti l i t come s i n contac t wit h termina l en d o f th e wire .
DIGITA L MULTIMETE R(Commerciall y available ) o rKS - AH M - 3 2 - 00 3
STACKIN G PATC HCORD
BACKPROB E SE T
07SA Z - 001000 A (tw o required ) BACKPROB E ADAPTE R
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CAUTION:

Puncturing the insulation on a wire can cause poor or intermittent electrical connections.

Bring the tester probe into contact with the terminal from the connector side of wire harness connectors in the engine

compartment. For female connectors, just touch lightly with the tester probe and do not insert the probe.

RUBBER SEAL

WIRE HARNESS

TERMINAL
TESTER PROBEProCarManuals.com

Troubleshooting
Troubleshooting Procedure s (cont'd )
Sympto m Char t
Liste d belo w ar e symptom s an d probabl e cause s fo r problem s tha t D O NO T caus e th e Malfunctio n Indicato r Lam p (MIL ) t o
com e on .
I f th e MI L wa s reporte d on , g o to pag e 11-38 .
Troubleshoo t eac h probabl e caus e in th e orde r liste d (fro m lef t t o right ) unti l th e sympto m is eliminated .
Th e probabl e caus e an d troubleshootin g pag e referenc e ca n b e foun d o n nex t page .
Othe r Probabl e Causes :
Engin e wil l no t start
— Compressio n
— Engin e locke d u p
— Timin g bel t
— Startin g syste m
— Overheatin g
— Batter y Troubleshoo
t fo r misfir e o n page s 11-90 , 11-9 4
PROBABL E CAUS ESYMPTO M
Engine wil l no t start
Har d startin g
Col d fas t idl e to o lo w
Col d fas t idl e to o hig h
Idl e spee d fluctuate s
Misfir e o r roug h runnin g
Lo w powe r
Engin e stall s4,2,3,5,19,13, 1
2,4,10,12,1 8
7,6
7,9, 8
7,9,8
2,8,9 , 11,16 , 15,17,1 0
2,4,10 , 19,7,5 , 1 4
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Probable Caus e Lis t (Fo r th e DT C chart , se e pag e 11-52 .)
Probabl e Caus e
1
2
3
4
5
6
7
8
9
10
1 1
1 2
13
1 4
15
16
17
1 8
19
Pag e
11-6 1, 11-62
11-132, 11-13 9
11-14 3
Sectio n 2 3
See DTC chart
See DTC chart
11-12 8
11-15 1
11-150
See DTC chart
See DTC chart
See DTC chart
11-122 , 11-125
11-12 7
11-14 9
11-154
11-159
11-16 7
System
Engin e Contro l Modul e (ECM )
Fue l pressur e an d fue l pum p rela y
PGM-F I mai n rela y
Ignitio n syste m
Crankshaf t Position/Cylinde r Positio n senso r circui t
Intak e Ai r Temperatur e (IAT ) senso r circui t
Idl e spee d adjustmen t
Throttle bod y
Throttl e cabl e
Manifol d Absolut e Pressur e (MAP ) senso r
Throttl e Positio n (TP ) senso r
Barometri c pressur e (BARO ) senso r
A/ T gea r positio n signa l o r clutc h switc h signa l
Brak e switc h signa l
Ai r Cleane r
Intak e Ai r Bypas s (IAB ) contro l syste m an d intak e ai r pip e
Thre e Wa y Catalyti c Converte r (TWC )
Evaporativ e emissio n (EVAP ) contro l
Contaminate d fue l
(cont'd)
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Troubleshooting

Troubleshooting Procedures (cont'd)

ECM Data

By connecting the OBD II scan tool or the Honda PGM Tester to the 16P data link connector (DLC), various data can be

retrieved from the ECM. The items listed in the table below conform to the SAE recommended practice.

The Honda PGM Tester also reads data beyond that recommended by SAE.

Understanding this data will help to find the causes of intermittent failures or engine problems.

NOTE:

The "operating values" given below are approximate values and may be different depending on the environment and

the individual vehicle.

Unless noted otherwise, "at idle speed" means idling with the engine completely warmed up, A/T in or position,

M/T in neutral, and the A/C and all accessories turned off.

Data
Description
Operating Value

Freeze Data

Diagnostic

Trouble Code

(DTC)
If the ECM detects a problem, it will store it as a code

consisting of one letter and four numbers.

Depending on the problem, an SAE-defined code

(POxxx)
or a
Honda-defined code
(P1xxx)
will
be
output

to the tester.
If no problem is detected,

there is no output.

YES

Engine Speed
The ECM computes engine speed from the signals sent

from the Crankshaft Position sensor.

This data is used for determining the time and amount

of fuel injection.
Nearly the same as

tachometer indication at

idle speed:

A/T:
780 ± 50 rpm

M/T:
800 ± 50 rpm
YES

Vehicle Speed
The ECM converts pulse signals from the Vehicle

Speed Sensor (VSS) into speed data.
Nearly the same as

speedometer indication
YES

Manifold

Absolute

Pressure (MAP)
The absolute pressure created in the intake manifold by

engine load and speed.
With engine stopped:

Nearly the same as atmo-

spheric pressure at idle

speed:

24-37kPa(180-280

mmHg, 7.1-11.0 inHg)
YES

Engine Coolant

Temperature

(ECT)
The ECT sensor converts coolant temperature into volt-

age and signals the ECM. The sensor is a thermistor

whose internal resistance changes with coolant tem-

perature. The ECM uses the voltage signals from the

ECT sensor to determine the amount of injected fuel.
With cold engine:

Same as ambient temper-

ature and IAT

With engine warmed up:

approx. 176-194°F

(80 - 90°C)
YES

Heated Oxygen

Sensor (HO2S)

(Bank 1, Sensor 1)

(Bank 1, Sensor 2)

(Bank 2, Sensor 1)

(Bank 2, Sensor 2)
The Heated Oxygen Sensor detects the oxygen content

in the exhaust gas and sends voltage signals to the

ECM. Based on these signals, the ECM controls the

air/fuel ratio. When the oxygen content is high (that is,

when the ratio is leaner than the stoichiometric ratio),

the voltage signal is lower. When the oxygen content is

low (that is, when the ratio is richer than the stoichio-

metric ratio), the voltage signal is higher.
0.0-1.25V

At idle speed:

about 0.1-0.9V

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