1997 ACURA NSX ignition

Function Selection and Operation Check

This check will quickly and automatically select and operate all functions of the climate control system, in the combina-

tions and sequence shown below. It may help clarify a problem, or identify one that didn't show up when you perform

the self-diagnosis circuit check.

Turn the FAN switch to AUTO, then push in both the MODE and AUTO buttons and hold them in while you start the

engine. The control unit will then automatically run the check in eight steps, one step every five seconds.

To stop at one of those steps, push the MODE button; to continue, push it again for each step after that.

Pushing the OFF button or turning the ignition OFF, will turn off the check.

Check the temperature, volume, and source of the air flow, and compare it to what the chart shows it should be.ProCarManuals.com

Mode Control Motor

Test

1. Disconnect the mode control motor connector, turn

the ignition switch ON (II), and move the blower

switch to the middle setting.

2. Connect battery power to the No. 1 terminal of the

mode control motor, then connect ground to the No.

2 terminal. The mode control motor should run, and

stop at VENT.

If it doesn't, reverse the connections; the mode

control motor should run, and stop at DEF.

NOTE: If the mode control motor does not run,

remove it, and check the mode control linkage and

doors for smooth movement. If the mode control

linkage and doors move smoothly, replace the

mode control motor.
3. Plug the connector back into the motor. Operate

the mode switch on the climate control unit to each

mode. Verify that the mode control motor has mov-

ed to the selected position by checking the air flow

for the mode selected.

NOTE: If the motor did not move, turn the ignition

switch OFF, and disconnect the mode control mo-

tor connector. Turn the ignition switch ON (II), then

connect battery power to No. 1 and No. 2 terminals

as shown in step 2. Power the mode control motor

to move the doors to the mode selected.

4. Disconnect the mode control motor connector at

each mode selected and check for continuity bet-

ween the motor terminals according to the table

below.

5. Replace the mode control motor if there is no con-

tinuity for any one mode selected.ProCarManuals.com

Ignition Switch

Test

1. Remove the dashboard lower cover (see next

column).

2. Disconnect the 7P connector from the floor wire

harness.

3. Check for continuity between the terminals in each

switch position according to the table.

7P CONNECTOR

BLK/YEL (IG1)

BLU/WHT (IG2-B)
View from

wire side

BLK/WHT 1ST)

WHT/BLK (BAT-B)

WHT/RED (ACC)
Electrical Switch Replacement

1. Remove the dashboard lower cover, and disconnect

the floor wire harness connectors.

DASHBOARD

LOWER

COVER

2. Disconnect the 7P connector from the floor wire

harness.

3. Insert the key, and turn it to "0".

4. Remove the two screws, and replace the switch.

LOCK CYLINDER

SWITCH
WHT (IG2-A)

WHT (BAT-A)ProCarManuals.com

Ignition Switch

Steering Lock Removal/Installation (cont'd)

8. Center-punch the shear bolt, and drill its head off

with a 5 mm (3/16 in) drill bit. Do not damage the

switch body.

9. Remove the shear bolt from the switch body.

10. Insert the key, and turn it to "I".

11. Push the lock pin, and pull out the steering lock

assembly.

STEERING LOCK

BODY
Installation:

1. Turn the key to "I", push the pin, and insert the

steering lock assembly into the steering column

until it clicks into place.

2. Loosely tighten the new shear bolt. Make sure the

projection on the ignition switch is aligned with the

hole in the steering column.

3. Insert the ignition key, and check for proper opera-

tion of the steering wheel lock and that the ignition

key turns freely.

4. Tighten the shear bolt until the hex head twists off.

5. Install in the reverse order of removal. Install the 3P

connector harness carefully because this harness

serves as communication link.

SHEAR BOLT

TWIST-OFF PORTION

6. After installing, check the immobilizer system.ProCarManuals.com

— If the starter still does not crank the engine,

remove the starter and diagnose its internal

problems.

— If the starter cranks the engine, check for an

open in the BLK/WHT wire and connectors be-

tween the starter and ignition switch. Check the

ignition switch.

On cars with automatic transmission, check the

A/T gear position switch (neutral position

switch) and connector.

On cars with manual transmission, check the

starter cut relay, clutch interlock switch and

connectors.

NOTE: Check the No. 29 (50 A) fuse and the

starter cut relay, and inspect the security alarm

system.

3. Check for wear or damage:

The starter should crank the engine smoothly and

steadily.

If the starter engages, but cranks the engine er-

ratically, remove the starter motor. Inspect the

starter, drive gear and flywheel ring gear for

damage.

Check the drive gear overrunning clutch for binding

or slipping when the armature is rotated with the

drive gear held. Replace the gears if damaged.

4. Check cranking voltage and current draw:

Voltage should be no less than 8.5 volts.

Current should be no more than 350 amperes.

If voltage is too low, or current draw too high,

check for:

Low battery.

Open circuit in starter armature commutator

segments.

Starter armature dragging.

Shorted armature winding.

Excessive drag in engine.
5. Check cranking rpm:

Engine speed during cranking should be above 100

rpm.

If speed is too low, check for:

Loose battery or starter terminals.

Excessively worn starter brushes.

Open circuit in commutator segments.

Dirty or damaged helical spline or drive gear.

Defective drive gear overrunning clutch.

6. Check the starter disengagement:

Depress the clutch pedal all the way (M/T) or shift to

or position (A/T), turn the ignition switch to

"Start (III)", and release to ON (II).

The starter drive gear should disengage from the

flywheel ring gear.

If the drive gear hangs up on the flywheel ring gear,

check:

Solenoid plunger and switch for malfunction.

Drive gear assembly for dirt or damaged over-

running clutch.ProCarManuals.com

Ignition Syste m
Componen t Locatio n Inde x
IGNITIO N TIMIN G CONTRO L SYSTE M
Description , pag e 23-8 9
Inspection , pag e 23-9 1
Troubleshooting , sectio n 1 1
SERVIC E CHEC KCONNECTO R (2P )
(Connecto r color : BLU )
SPAR K PLU G (6 )
Inspection , pag e 23-9 6
NOIS E CONDENSE R
Test , pag e 23-9 7
TEST TACHOMETE R CONNECTO R
IGNITIO N CONTRO L MODUL E (ICM )
• Replacement , pag e 23-9 2
• Inpu t Test , pag e 23-9 3
• Troubleshooting , sectio n 1 1 IGNITIO
N COI L (6 )
• Removal , pag e 23-9 4
• Test , pag e 23-9 5 CRANKSHAF
T POSITION/CYLINDE R POSITIO N
(CKP/CYP ) SENSO R• Troubleshooting , sectio n 1 1
• Replacement , sectio n 5
SERVIC E LOO P
ProCarManuals.com

Description ——————————————————\
——————————————————\
———
Ignition Timin g Control :
Th e programme d ignitio n use d i n thi s engin e provide s optimu m contro l o f ignitio n timing . A microcompute r determine s
th e timin g i n respons e t o engin e spee d an d manifol d vacuu m pressure . Th e inpu t signal s ar e transmitte d b y th e crank -
shaf t position/cylinde r positio n (CKP/CYP ) sensor , throttl e positio n (TP ) sensor , EC T sensor , an d MA P sensor . Thi s sys -
tem , no t dependen t o n a governo r o r vacuu m diaphragm , i s capabl e o f settin g lea d angle s wit h complicate d characteristic s
whic h canno t b e provide d b y conventiona l governor s o r diaphragms .
Basi c Contro l
Determinatio n of ignitio n timing/curren t duration :
Th e EC M ha s store d withi n i t th e optimu m basi c ignitio n timin g fo r operatin g condition s base d upo n engin e spee d an d in -
tak e manifol d pressure . Wit h compensatio n b y signal s fro m sensors , th e syste m determine s optimu m timin g fo r ambien t
condition s an d send s voltag e pulse s t o th e ICM .
Compensatio n o f Ignitio n Timing :
Compensatio n Ite m
Idlin g
Compensatio n a t warm-u p
Engin e coolan t
temperatur e compensatio nRelate
d Senso r an d Informatio n
CKP/CY P sensor , MA P senso r
Engin e coolan t temperatur e
(ECT) senso r
ECT senso r Descriptio
n
Ignitio n timin g i s controlle d t o th e targe t spee d
wit h compensatio n accordin g t o th e idlin g speed .
La g angl e i s adjuste d accordin g t o warm-u p con -
dition s t o brin g abou t a goo d balanc e betwee n
operatin g performanc e an d exhaus t ga s level .
Compensatio n fo r lea d angl e a t low coolan t
temperatur e an d la g angl e a t hig h coolan t
temperature .
Contro l a t Star t
Ignitio n timin g is fixe d a t 5 ° BTD C fo r cranking . Th e crankin g is detecte d b y th e CY P senso r (crankin g rpm ) an d starte r signal .
Misfirin g Detectio n
A s par t o f th e OB D II misfirin g detectio n system , eac h o f th e ignitio n coil s ha s a built-i n spar k plu g voltag e sensor . Thi s
senso r detect s th e lon g duratio n hig h voltag e whic h occur s i n cas e o f unfavorabl e combustio n o r misfiring . (Fo r details ,
se e sectio n 11 .)
ProCarManuals.com

Ignition Timin g Inspectio n
SRS component s ar e locate d in thi s area . Revie w th e SR S
componen t locations , precautions , an d procedure s i n th e
SR S (sectio n 24 ) befor e performin g repair s o r service .
1 . Pul l ou t th e servic e chec k connecto r locate d unde r
th e middl e o f th e dash . Connec t th e BL U an d BRN /
BL K terminal s wit h th e SC S servic e connector .
2 . Star t th e engine . Hol d th e engin e a t 3,00 0 rp m wit h
no loa d (A/ T i n o r position , M/ T i n neutral )
unti l th e radiato r fa n come s on , the n le t i t idle .
NOTE : I f yo u sto p th e engin e o r tur n th e ignitio n
switc h OF F afte r warm-u p wit h th e SC S servic e con -
necto r connected , th e engin e wil l idl e a t th e bas e
idl e speed . Tha t is , i t wil l no t b e controlle d b y th e
ECM . T o retur n t o th e norma l idl e speed , pres s th e
acclerato r peda l on e time .
SERVIC E CHEC K CONNECTO R (2P )
SC S SERVIC E CONNECTO R
07PAZ-001010 0
3. Chec k th e idl e spee d (se e pag e 23-92 ).
4 . Connec t a timin g ligh t t o th e servic e loop ; whil e th e
engin e idles , poin t th e ligh t towar d th e pointe r o n
the timin g bel t cover .
SERVIC E LOO P
TIMIN G LIGH T
5. Chec k th e ignitio n timin g wit h al l electrica l system s
ar e turne d OFF .
Ignitio n Timing : 15 ° ± 2° BTD C (RE D mark ) a t
Idl e Spee d (rpm) :
POINTE R
6. I f th e ignitio n timin g i s ou t o f spec , replac e th e ECM .
7 . Remov e th e SC S servic e connecto r fro m th e servic e
chec k connector .
CRANKSHAF T PULLE Y
RE
D MAR K
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