sensor ACURA NSX 1991 Service Manual PDF

Radiator an d Condense r Fa n Control s
Radiator Fa n Contro l Senso r Tes t
NOTE : Blee d ai r fro m th e coolin g syste m afte r install -
in g th e radiato r fa n contro l senso r (se e sectio n 10 ).
1 . Remov e th e radiato r fa n contro l senso r fro m th e
thermosta t cover .
2 . Suspen d th e radiato r fa n contro l senso r i n a con -
taine r o f coolan t a s shown .
THERMOMETE R
RADIATOR FA NCONTRO L SENSO R
ENGIN E
OIL
3. Hea t th e coolant , an d chec k coolan t temperatur e
with a thermomete r (se e tabl e below) .
4. Measur e th e resistanc e betwee n th e A an d B ter -
minal s accordin g t o th e table .
5 . I f unabl e t o obtai n th e abov e readings , replac e th e
radiato r fa n contro l sensor .
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Gauge Assembly
Gauge/Terminal Location Index
SRS components are located in this area. Review the SRS component locations, precautions, and procedures in the SRS

section (24) before performing repairs or service.

SPEEDOMETER:

Indicates 60 mph [60km/h] at 1.026 [637]

rpm of the vehicle speed sensor (VSS).
FUEL GAUGE: Gauge test, page 23-134 Sending Unit Test, page 23-135

VOLTAGE METER:
If, with the No. 5 (15 A) fuse

and other gauges

OK, the pointer of the

voltage meter does not move at all,
replace the voltage

meter.

SAFETY INDICATOR SYSTEM:
See page 23-145 ('93-'96) ('91-'92)A/T GEAR POSITION
INDICATOR SYSTEM:
See page 23-156 ENGINE OIL PRESSURE
GAUGE:
Test page 23-137
ENGINE COOLANT TEMPERATURE (ECT) GAUGE:
Gauge Test, page 23-136 Sender Test, page 23-136
TACHOMETER:

Indicates 100 rpm at 300 pulses per minute

of the igniter unit.ProCarManuals.com

Vehicle Speed Sensor (VSS)

Replacement

1. Disconnect the 3-P connector from the vehicle speed

sensor (VSS).

3-P CONNECTOR

MOUNTING BOLTS

2. Remove the mounting bolts and the VSS, then take

out the VSS assembly.

NOTE: The VSS drive link is a very small part, be

careful not to lose it.

3. Install in the reverse order of removal.
COVER

VSS

DRIVE LINKProCarManuals.com

Safety Indicator

Component Location index

SRS components are located in this area. Review the SRS
component locations, precautions, and procedures in the
SRS section (24) before performing repairs or service.
SAFET
Y
INDICATOR (In the gauge assembly)

Removal, page 23-129 ('93-'96) ('91-'92)

Troubleshooting, page 23-152 ('94-'96) ('91-'93)
Input Test, page 23-150 ('94-'96) ('93) ('91-'92)

CEILING LIGHT

Test, page 23-201
ROOF LOCK SWITCH ( * 1)

Test, page 23-154 ('94-'96) ('91-'93)

PASSENGER'S DOOR SWITCH

Test, page 23-204
HIGH MOUNT BRAKE LIGHT

Test, page 23-211

BRAKE SWITCH

Test, page 23-211

DRIVER'S DOOR SWITCH

Test, page 23-204

ROOF HOLDER SWITCH (* 1)

Test, page 23-155 ('94-'96) ('91-'93)

ENGINE COMPARTMENT LID SWITCH

Test, page 23-325 ('93-'96) ('91-'92)
LEFT BRAKE LIGHT
FAILURE SENSOR

Test, page 23-153
TRUNK LATCH SWITCH

Test, page 23-205
RIGHT BRAKE LIGHT

FAILURE SENSOR

Test, page 23-153

*1: NSX-T (open top) only

Description

Safety Indicator System: LED's are used to indicate when the trunk lid, engine compartment lid, a door, or the roof is not latched, or when a brake
light is faulty, or when the roof is not stored or improperly stored in its holder. The LED's will go on and stay on for about
two seconds after the ignition switch has been turned ON, to show that the system circuit is functioning.

Brake Light Bulb Failure Indicator:

If all brake light bulbs are OK, the indicator light stays off because the ORN/WHT wire is grounded by the two brake light
failure sensors connected in series. With the brake lights off, the ground is provided through the diode, the failure sensor relay coil, and bulb filaments. With the brake light on, all four relays (two in the left sensor, two in the right sensor), con-
nected in series, supply ground. If any of the four bulbs is not working, the chain is broken and the ORN/WHT wire is not
longer grounded. The indicator light comes on.ProCarManuals.com

Brake Ligh t Failur e Senso r Tes t
1. Firs t mak e sur e th e brak e light s com e o n whe n th e
brak e peda l i s pressed .
• I f al l th e brak e light s com e on , g o t o ste p 2 .
• I f on e o f th e brak e light s doe s no t com e on , chec k
whethe r th e bul b is blown . I f th e bul b is OK , g o
to ste p 2 .
• I f non e of the brak e light s com e on , chec k th e
brak e ligh t circui t.
2 . Ope n th e trun k lid , an d remov e th e tri m pane l tha t
cover s th e righ t taillight . Watc h th e
ligh t i n th e safet y indicato r whe n th e A (WHT/GRN )
wir e o f th e 6- P connecto r i s grounde d an d th e igni -
tion switc h is turne d fro m OF F to O N (II) .
RIGH T FAILUR E SENSO R
6- P CONNECTO R
Vie w fro m wir e sid e
If th e ligh t come s o n an d stay s
on , chec k fo r a n ope n in th e A (WHT/GRN ) wir e
betwee n th e safet y indicato r an d th e righ t failur e
sensor .
If th e ligh t doe s no t sta y on , g o
t o ste p 3 .
3. Watc h th e ligh t a s yo u tur n th e igni -
tion switc h fro m OF F to O N (II) , wit h th e B (GRN )
wire o f th e 6- P connecto r grounde d an d th e brak e
peda l pressed .
If th e ligh t come s o n an d stay s
on, replac e th e righ t failur e sensor .
If th e ligh t doe s no t sta y o n , g o
t o ste p 4 . 4
. Remov e th e rea r tri m pane l tha t cover s th e lef t tail -
light . Watc h th e ligh t a s yo u tur n th e
ignitio n switc h fro m OF F to O N (II) , wit h th e A (GRN )
wire o f th e 6- P connecto r grounde d an d th e brak e
peda l pressed .
LEFT FAILUR E SENSO R
6-P CONNECTO R
View fro m wir e sid e
If th e ligh t come s o n an d stay s
on , ther e is a n ope n in th e A (GRN ) wir e betwee n
th e lef t failur e senso r an d th e righ t failur e sensor .
If th e ligh t doe s no t sta y on , g o
t o ste p 5 .
5. Watc h th e ligh t a s yo u tur n th e igni -
tion switc h fro m OF F to O N (II) , wit h th e B (BLK ) wir e
of th e 6- P connecto r grounde d an d th e brak e peda l
pressed .
• I f th e ligh t come s o n an d stay s
on , replac e th e lef t failur e sensor .
• I f th e ligh t doe s no t sta y on , chec k
fo r a n ope n in th e B (BLK ) wir e betwee n th e lef t
failur e senso r an d ground , an d chec k fo r a poo r
groun d a t G551 .
ProCarManuals.com

Brake Lights

Component Location Index

BRAKE SWITCH
Test, page 23-211

HIGH MOUNT BRAKE LIGHT (LED)
LED Replacement, page 23-212
('94-'96) ('91-'93)

Replacement, page 23-212 ('94-'96) ('91-'93) Test, page 23-211

RIGHT TAILLIGHT
Bul
b
Replacement, page 23-196
Failure Sensor Test, page 23-153
LEFT TAILLIGHT Bulb Replacement, page 23-196 Failure Sensor Test, page 23-153
ProCarManuals.com

(G551) '95-'96 Models.
(G401,G402,G551) '93-94 Models or
Brake Switch
Test

1
.
If one of the brake lights does not go on, check that
brake
light bulb in the taillight or the high mount light
2
.
If none of the brake lights 90 on, check the No. 45 (2

0
A) fuse in the under-hood fuse/relay box.
3

.
If the fuse and bubs are OK, disconnect the 4-P con- necto

r
from the brake switch.

4-P CONNECTOR

BRAKE

SWITCH
BRAKE
PEDAL

4. Check for continuity between the B and C terminals. There should be continuity with the brake pedal

pushed.

If there is no continuity, replace the switch or ad-
just pedal height (see section 19).
If there is continuity, but the brake lights do not
go on, inspect for:
Poor ground (G401,G501) '91-'92 Models or
An open in the WHT/GRN or GRN/WHT wire. Faulty brake light failure sensors (see page 23-153). High Mount Brake Light Test
1. Open the trunk lid and engine compartment lid.
2. Disconnect the 2-P connector from the trunk wire
harness.

TRUNK WIRE HARNESS

SIDE WIRE
HARNESS

View from terminal side
View from

terminal

side
3. Connect a voltmeter positive lead to the GRN/WHT terminal and the negative lead to the BLK terminalof the side wire harness side of the connector.
Push the brake pedal, and check for voltage between
the GRN/WHT and the BLK terminals. There should be battery voltage. If there is no voltage, check for:
— Blown No. 45 (20 A) fuse in the under-hood
fuse/relay box.
— An open in the GRN/WHT or BLK wire.
— Faulty brake switch.
If there is battery voltage, go to step 4.
4. Connect battery power to the GRN/WHT terminal and ground to the BLK terminal of the trunk wireharness side of the connector.
Check that all the LEDs of the high mount brake light

go on.

If the high mount brake light does not go on,check for an open in the wires
in the trunk lid.
If the wires in the trunk lid are OK, replace the
high mount brake light.
If some of the LEDs do not go on,
replace the high
mount brake light assembly.
GRN/WHT BLK


BLK GRN/WHTProCarManuals.com

Side Marker/Turn Signal/Hazard Flasher System

Description

To cope with dimensional requirements for the airbag components and to offer better operational feel, the turn signal

lever and the cancel mechanism are separated mechanically, and connected electrically instead.

The system cancels the turn signals electrically, by means of a solenoid, after a turn is made. A sensor mechanism which

consists of cancel cams on the steering shaft, and a pair of switches, is used to monitor the steering shaft's position.

STEERING SHAFT

CANCEL CAM

CANCEL SWITCH

TURN SIGNAL LEVER

SOLENOIDProCarManuals.com

Horns

Component Location Index

SRS components are located in this area. Review the

SRS component locations, precautions, and procedures

in the SRS section (24) before performing repairs or ser-

vice.

HORN RELAY

Test, page 23-249

UNDER-HOOD RELAY

BOX A
CABLE REEL

Test, page 23-250
HORN SWITCH
Test, page 23-249
Overhaul, section 17
SECURITY HORNTest, page 23-248
LEFT HORN
Test, page 23-248
RIGHT HORN
Test, page 23-248
SECURITY CONTROL
UNIT
Inpu
t
Test, page 23-320
('94-'96) ('93) ('91-'92)
UNDER-HOOD

FUSE/RELAY BOX

Description

Security Alarm System:

The security alarm system is an anti-theft alarm system. If someone tries to open the trunk, hood or either door without

the ignition key, or if the roof is not fully latched the security control unit senses a signal from the sensors and activates
relays to flash the headlights and sound the horn for about two minutes.ProCarManuals.com

ECM

See section 11

VEHICLE SPEED SENSOR (VSS)

Test, page 23-131 ('94-'96) ('91-'93)ProCarManuals.com