1991 ACURA NSX Service Repair Manual

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.

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.ProCarManuals.com

Troubleshooting

Tips and Precautions

• Insert the connector all the way, and make sure it is

securely locked.

• Position wires so that the open end of the cover

faces down.

Face

open end

down

Handling Wires and Harnesses

• Secure wires and wire harnesses to the frame with

their respective wire ties at the designated locations.

• Remove clips carefully; don't damage their locks.

Slip pliers under the clip base and through the hole at an

angle, then squeeze the expansion tabs to release the

clip.

SNAP-RING PLIER

After installing harness clips, make sure the harness

doesn't interfere with any moving parts.

Keep wire harnesses away from exhaust pipes and

other hot parts, from sharp edges of brackets and

holes, and from exposed screws and bolts.
Seat grommets in their grooves properly.

NOT GOOD

Testing and Repairs

• Do not use wires or harnesses with broken insulation.

Replace them or repair them by wrapping the break

with electrical tape.

• After installing parts, make sure that no wires are

pinched under them.

• When using electrical test equipment, follow the

manufacturer's instructions and those described in

this manual.

• If possible, insert the probe of the tester from the wire

side (except waterproof connector).

Use a probe with a tapered tip.

• Refer to the instructions in the Honda Terminal Kit for

identification and replacement of connector terminals.ProCarManuals.com

Five-step Troubleshooting

1. Verify The Complaint

Turn on all the components in the problem circuit to

verify the customer complaint. Note the symp-

toms. Do not begin disassembly or testing until you

have narrowed down the problem area.

2. Analyze The Schematic

Look up the schematic for the problem circuit.

Determine how the circuit is supposed to work by

tracing the current paths from the power feed

through the circuit components to ground. If

several circuits fail at the same time, the fuse or

ground is a likely cause.

Based on the symptoms and your understanding of

the circuit operation, identify one or more possible

causes of the problem.

3. Isolate The Problem By Testing The Circuit

Make circuit tests to check the diagnosis you made

in step 2. Keep in mind that a logical, simple pro-

cedure is the key to efficient troubleshooting. Test

for the most likely cause of failure first. Try to make

tests at points that are easily accessible.
4. Fix The Problem

Once the specific problem is identified, make the

repair. Be sure to use proper tools and safe

procedures.

5. Make Sure The Circuit Works

Turn on all components in the repaired circuit in all

modes to make sure you've fixed the entire pro-

blem. If the problem was a blown fuse, be sure to

test all of the circuits on that fuse. Make sure no

new problems turn up and the original problem

does not recur.ProCarManuals.com

Relay and Control Unit Locations

Front Compartment

HORN RELAY

A/C COMPRESSOR CLUTCH

RELAY

RADIATOR FAN

LOW RELAY

RADIATOR FAN

HIGH RELAY

CONDENSER FAN RELAY

UNDER-HOOD RELAY BOX A
LEFT HEADLIGHT RETRACTOR

CUT RELAY
WINDSHIELD WIPER

LOW RELAY

WINDSHIELD WIPER

INTERMITTENT RELAY

POWER AMPLIFIER

RELAY
ABS

REAR FAIL-SAFE RELAY

ABS FRONT

FAIL-SAFE RELAY

HEADLIGHT RELAY
RIGHT HEADLIGHT RETRACTOR RELAY

Wire colors: BLU/GRN,

BRN/WHT, BLU/RED,

GRN/YEL, and BLK

LEFT HEADLIGHT RETRACTOR RELAY

Wire colors: BLU/BLK,

WHT/BLK, GRN/RED,

BLU,
and BLK
RIGHT HEADLIGHT RETRACTOR

CUT RELAY

BLOWER RELAY

BLOWER HIGH RELAY

WINDSHIELD WIPER

HIGH RELAY

WINDSHIELD

WASHER RELAY

UNDER-HOOD

RELAY BOX B

DIMMER RELAY

POWER WINDOW

RELAY

TAILLIGHT RELAY

ABS MOTOR RELAY

UNDER-HOOD FUSE/RELAY BOXProCarManuals.com

Relay and Control Unit Locations

Dashboard

TURN SIGNAL/HAZARD

RELAY
CLIMATE CONTROL UNIT

UNDER-DASH FUSE BOX
FOOT WELL LIGHT

DASHBOARD

LOWER COVER

INTEGRATED

CONTROL UNIT
SRS UNITProCarManuals.com

Dashboard, Door and Floor

DRIVER'S DOOR PANEL

ABS CONTROL UNIT

DAYTIME RUNNING

LIGHTS CONTROL

UNIT (Canada)

POWER WINDOW

CONTROL UNIT

STARTER CUT RELAY

Wire colors: BLK/WHT,

BLK/WHT, BLK/GRN,

and BLK/BLU

SECURITY CONTROL UNIT

CIGARETTE LIGHTER

RELAY

Wire colors: YEL/RED,

BLU/GRN, BRN/YEL, and BLK
FOOT WELL BASS SPEAKER
EPS CONTROL UNIT

(Behind foot well

bass speaker)

RIGHT FRONT FLOOR

PANEL

SRS UNIT
POWER DOOR LOCK

CONTROL UNITProCarManuals.com

Relay and Control Unit Locations

Rear Bulkhead

PGM-FI MAIN RELAY
THROTTLE VALVE CONTROL

MOTOR RELAY

Wire colors: BLK,

YEL/BLK, GRN/RED,

and WHT/BLU
TCS CONTROL UNIT
TRANSMISSION CONTROL

MODULE (TCM) (A/T)

PULSE UNIT (M/T)

DASH LIGHTS

BRIGHTNESS

CONTROL UNIT
FAN CONTROL

UNIT

ECMProCarManuals.com

RETRACTABLE HEADLIGH TCONTROL UNI TINTERLOC K CONTRO LUNIT (A/T )
FUEL PUM P RELA YWire colors : YEL , RED ,BLK/YEL , an d BLK/RE D
ProCarManuals.com