1991 ACURA NSX jump start

Charging System

Troubleshooting

Alternator/Regulator Test

Use the SUN VAT-40 (or equivalent) tester.
2. Attach the negative tester cable and the voltmeter

negative lead to the top of the intake manifold.

LOAD ADJUSTER

(CARBON PILE)
FULL FIELD

LEAD (BLU)

VOLTMETER

NEGATIVE

LEAD (BLK)

VOLT

SELECTOR

FIELD

SELECTOR

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
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

ALTERNATOR
TEST SELECTOR

SWITCHProCarManuals.com

Fuel Gaug e
Gauge Tes t
1. Befor e testing , chec k th e No . 5 (1 5 A ) fus e i n th e
under-das h fus e box .
2 . Remov e th e rea r bulkhea d pane l behin d th e driver' s
seat , the n remov e th e acces s panel .
3 . Disconnec t th e 3- P connecto r fro m th e fue l gaug e
sendin g unit .
ACCES S PANE L
4. Connec t th e voltmete r positiv e prob e t o th e B
(YEL/WHT ) termina l an d th e negativ e prob e t o th e
C (BLK ) terminal , the n tur n th e ignitio n switc h O N
(II) . Ther e shoul d b e betwee n 5 an d 8 V .
• I f th e voltag e i s a s specified , g o t o ste p 5 .
• I f th e voltag e i s no t as specified , chec k for :
- A n ope n i n th e YEL , YEL/WH T o r BL K wire .
- Poo r groun d (G403) .
5 . Tur n th e ignitio n switc h OFF . Connec t a jumpe r wir e
betwee n th e B (YEL/WHT ) an d A (BLK ) terminals .
CAUTION : D o no t appl y batter y voltag e to th e ter -
minals ; i t wil l damag e th e fue l gauge .
6. Tur n th e ignitio n switc h O N (II) . Chec k tha t th e
pointe r o f th e fue l gaug e start s movin g towar d th e
"F " mark .
CAUTION : Tur n th e ignitio n switc h OF F befor e th e
pointe r reache s th e "F " mar k o n th e gaug e dial ; i f
yo u don't , yo u ma y caus e damag e to th e fue l gauge .
• I f th e pointe r o f th e fue l gaug e doe s no t mov e a t
all , replac e th e gauge .
• I f th e fue l gaug e i s OK , chec k th e sendin g unit .
23-13 4
3-P CONNECTO R
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Engine Coolan t Temperatur e (ECT ) Gaug e
ECT Gaug e Tes t
1. Befor e testing , chec k th e No . 5 (1 5 A ) fus e i n th e
under-das h fus e box .
2 . Mak e sur e th e ignitio n switc h i s OFF , the n discon -
nec t th e YEL/GR N wir e fro m th e EC T sendin g uni t
an d groun d i t wit h a jumpe r wire .
YEL/GR NWIRE
ECT SENDIN G
UNI T
3. Tur n th e ignitio n switc h O N (II) .
Chec k tha t th e pointe r o f th e EC T gaug e start s mov -
in g towar d th e "H " mark .
CAUTION : Tur n th e ignitio n switc h OF F befor e th e
pointe r reache s th e "H " mar k o n th e gaug e dial ; i f
yo u don't , yo u ma y damag e th e gauge .
• I f th e pointe r o f th e gaug e doe s no t swin g a t all ,
chec k for :
— A n ope n in th e YE L o r YEL/GR N wire .
— Replac e th e EC T gaug e if th e fus e an d wirin g
is OK .
• I f th e EC T gaug e is OK , chec k th e sendin g unit .
ECT Sendin g Uni t Tes t
1. Disconnec t the YEL/GR N wire fro m the sendin g unit,
and wit h th e engin e cold , us e a n ohmmete r t o meas -
ure resistanc e betwee n th e positiv e termina l an d th e
engin e (ground) .
2 . Chec k th e temperatur e o f th e coolant .
3 . Ru n th e engine , an d measur e th e chang e i n resis -
tanc e wit h th e engin e a t operatin g temperatur e
(radiato r fa n come s on) .
4 . I f th e reading s yo u ge t ar e substantiall y differen t
fro m th e specification s above , replac e th e EC T send -
ing unit .
YEL/GR NWIRE
POSITIV E
• TERMINA L
EC T SENDIN G
UNI T
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Engine Oi l Pressur e Gaug e
Gauge Tes t
1. Befor e testing , chec k th e No . 5 (1 5 A ) fus e i n th e
under-das h fus e box .
2 . Mak e sur e th e ignitio n switc h i s OFF , the n discon -
nec t th e 2- P connecto r fro m th e engin e oi l pressur e
sending unit , an d groun d it wit h a jumpe r wire .
BLU/WH T WIR E
ENGIN E OI L PRESSUR EGAUGE SENDIN G UNI T
3. Tur n th e ignitio n switc h O N (II) .
Chec k tha t th e pointe r o f th e engin e oi l pressur e
gaug e start s movin g towar d th e "8 " mark .
CAUTION : Tur n th e ignitio n switc h OF F befor e th e
pointe r reache s th e "8 " mar k o n th e gaug e dial ; i f
yo u don't , yo u ma y caus e damag e t o th e gauge .
• I f th e pointe r o f th e gaug e doe s no t mov e a t all ,
chec k for :
- A n ope n i n th e YE L o r BLU/WH T wire .
— Replac e th e engin e oi l pressur e gaug e i f th e
wirin g is OK .
• I f th e engin e oi l pressur e gaug e i s OK , g o o n t o
ste p 4 .
4 . Chec k th e engin e oi l pressur e (se e sectio n 8 ).
• I f th e engin e oi l pressur e i s OK , replac e th e en -
gin e oi l pressur e sendin g unit .
Engin e Oi l Pressur e
Warnin g Syste m
Engine Oi l Pressur e Switc h Tes t
1. Rais e th e car , an d plac e safet y stand s in th e prope r
location s (se e sectio n 1 ).
2 . Remov e th e righ t rea r tire .
3 . Remov e th e YEL/RE D wir e fro m th e engin e oi l pres -
sur e switch .
ENGINE OI L PRESSUR E SWITC H
CRANKSHAF TPULLEY
4. Chec k continuit y betwee n th e positiv e termina l an d
engin e (ground ) wit h th e engin e off .
• I f ther e i s n o continuity , th e switc h i s OK .
• I f ther e i s continuity , d o no t replac e th e switch ;
firs t chec k othe r possibl e cause s i n ste p 6 .
6 . Mak e sur e engin e oi l leve l i s OK , the n chec k engine
oi l pressur e (se e sectio n 8 ).
• I f engin e oi l pressur e is OK , replac e th e engin e oi l
pressur e switch .
• I f oi l pressur e i s low , remove , inspect , and , i f
necessary , replac e th e oi l pum p (se e sectio n 8 ).
YEL/RE DWIRE
POSITIV E TERMINA L
OIL FILTE R
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Troubleshooting

Troubleshooting Guide
NOTE: Across each row in the chart, the systems that could be sources of a symptom are ranked in the order they should be inspected starting with . Find the symptom in the left column, read across to the most likely source, then refer
to the page listed at the top of that column. If inspection shows the system is OK, try the next most likely system , etc.
If codes other than those listed above are indicated, count the number of blinks again. If the Malfunction Indicator
Lamp is in fact blinking these codes, substitute a known-good ECM and recheck. If the indication goes away, replace
the original ECM.
If the Malfunction Indicator Lamp is on while the engine is running, jump the service check connector. If no code
is displayed (Malfunction Indicator Lamp stays on steady), the back-up system is in operation.
Substitute a known-good ECM and recheck. If the indication goes away, replace the original ECM.
USA:

Malfunction
Indicator
Lamp (MIL)
CANADA:

Check

Engine

Light

PAGE

SYSTEM

SYMTOM
MALFUNCTION INDICATOR
LAMP"

TURNS ON

MALFUNCTION
INDICATOR LAMP BLINKS
ENGINE WON'T START
DIFFICULT TO START
ENGINE WHEN COLD
WHEN COLDFAST IDLE

OUT OF SPEC

IRREGULAR

IDLING
ROUGH IDLE
WHEN WARM

RPM

TOO HIGH
WHEN WARM
RPM

TOO LOW

WHILE
WARMING UP

FREQUENT

STALLING
AFTER

WARMING UP
MISFIRE OR

ROUGH

RUNNING

POOR
PERFORM-

ANCE
FAILS

EMISSION

TEST

LOSS OF

POWER
ENGINE

CONTROL

MODULE

11-42

HEATED

OXYGEN

SENSOR

11-48, 11-50
MANIFOLD
ABSOLUTE

PRESSURE
SENSOR

11-58
CRANKSHAFT

POSITION/
CYLINDER

POSITION
SENSOR

11-64

PGM-FI

ENGINE

COOLANT

TEMPERA-
TURE

SENSOR
THROTTLE
POSITION
SENSOR
INTAKE AIR
TEMPERA-

TURE

SENSOR
BAROMET-

RIC PRES-
SURE

SENSOR
IGNITION

OUTPUT

SIGNAL
VARIABLE VALVE

TIMING & VALVE

LIFT ELECTRONIC
CONTROL SOLENOID
VALVE

6-15

11-74

11-72
11-70

11-68
11-66
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PGM-FI System

Troubleshooting Flowchart
Engine Control Module (ECM) (cont'd)
Malfunction Indicator Lamp (MIL) stays on after two seconds.

Turn the ignition switch ON.

Connect the service check con-

nector terminals with a jumper

wire.
Does the MIL indicate
any Diagnostic Trouble

Code (DTC)?

Remove the jumper wire from the
service check connector.
Try to start the engine.Did the engine start?
Remove and inspect the ACG (S) (20 A) fuse in the engine compart-
ment fuse/relay box.
Is the fuse OK?
(To page 11-45) Go to self-diagnostic procedures
(see page 11-34).

Turn the ignition switch OFF.

Connect the test harness between

the ECM and connectors (see page 11-37).

Turn the ignition switch ON.
Measure voltage between C9 (+)

terminal and D22 (-) terminal.

Is there approx. 5V (A/T: 11 V)?
Repair short to body ground in
BLU wire between the ECM (C9),
TCM, EPS control unit, ABS con-
trol unit or TCS control unit and service check connector.
Repair open in BLU wire be-
tween ECM (C9) and service check connector.
Repair open in GRN/WHT wire
between service check con-
nector and ECM (D22).
Replace the fuse.
NOTE: After repair, disconnect the service check con-
nector jumper wire, test drive the car, and recheck the
MIL for a code. NOTE: When there is no code stored, the MIL will stay
on if the service check connector is jumped.
Connect the service
check connector termi-

nals with a jumper wire.

Measure voltage be-

tween C9 (+) terminal

and D22 (-) terminal.

Is there approx. 5 V(A/T:
11 V)?

Remove the jumper
wire from the service
check connector.
(To page 11-45)ProCarManuals.com

Fuel Supply System
Fuel Pump Resistor

Troubleshooting Flowchart

(To page 11-125) FUEL PUMP

RESISTOR

Inspect the PGM-FI main relay
(seepage 11-120).
Engine will not start.
Inspection of fuel pump

resistor.

Disconnect the fuel pump resis-
tor connector.
Measure the voltage between

BLK/YEL (+) (on harness side)

and body ground (-) when the ig-

nition switch is first turned ON.

Is there battery voltage?
(for 2 seconds)

Turn the ignition switch OFF.
Install a jumper wire between
two terminals on the wire harness side of fuel pump

resistor.

Turn the ignition switch to START position.
Does the engine start?
Turn the ignition switch OFF.
Disconnect the C489 (6P) con-
nector (located behind the seat
back panels). Replace the fuel pump resistor.ProCarManuals.com

Transmission Assembly

Removal

CAUTION: Use fender covers to avoid damaging

painted surfaces.
1. Check and record the rear wheel alignment (see section 18).
2. Disconnect the battery negative (—), and positive (+) cables from the battery.
3. Drain transmission oil. Reinstall the drain plug with a new washer.
Corrosion resistant bolt/nut 4. Remove the strut bar.
5. Remove the air cleaner assembly.
6. Remove the connectors from the control box and remove the control box.
CAUTION: Do not remove the vacuum tubes from
the control box.
7. Remove the wire harness holder, jumper connector and transmission ground cable.
8. Disconnect the switch connectors, then remove the back-up light switch and neutral positionswitch.
9. Disconnect the starter motor cables, then remove the starter motor.
10. Remove the transmission mount.
11. Remove the two transmission housing bolts.
TRANSMISSION HOUSING BOLTS

BACK-UP

LIGHT SWITCH

CONNECTOR

WIRE HARNESS HOLDER

STARTER MOTOR

CABLES
NEUTRAL

POSITION
SWITCH

CONNECTOR

STARTER
MOTOR
TRANSMISSION

GROUND

CABLE

TRANSMISSION
MOUNT
MOUNTING

BOLTS
TRANSMISSION

HANGER
TRANSMISSION
MOUNTING BOLTS
JUMPER

CONNECTOR

VEHICLE SPEED

SENSOR (VSS)

CONNECTOR

CONTROL BOX

Make sure lifts are placed properly, and

hoist brackets are attached to correct position (see sec-

tion 1).ProCarManuals.com