1991 ACURA NSX check engine

Emission Control System

Evaporative Emission Controls (cont'd)

(From page 11-137)
Warm up the engine to normal operating temperature (cooling
fan comes on). (From page 11-137)
Is there battery voltage ?

Inspect GRIM wire for an open

between ECU (A20) and the
connector. If wire is OK. substitute a
known-good ECU and recheck. If
symptom/incication goes away,
replace the orignal ECU.
Check for vacuum at #6 vacuum hose after starting the engine:
Is there manifold vacuum?
Disconnect the 6P connector.

Is there manifold vacuum?
Reconnect the hose. Inspect for a short to body
ground in GRN wire between ECU (A20) and the connector.
If wire is OK, substitute aknown-good ECU and recheck. If
symptom/indication goes away,
replace the original ECU.
Remove fuel filler cap.
(To page 11-139) Inspect vacuum hose
routing.
If OK, replace purge
cut-off solenoid valve. Repair open in BLK/
YEL wire between No. 2 fuse and the 6P con-
nector.ProCarManuals.com

Transmission Assembly

Installation

NOTE: Check that the two dowel pins are installed in the clutch housing. 1. Place the transmission on the transmission jack, and raise it to the engine level.
2. Set the release fork to the clutch housing, (see page, 13-9)
3. Install the 2 transmission housing mounting bolts and engine stiffener.
4. Install the 3 rear transmission mounting bolts.
5. Loosen the front engine mounting bolt, then install the 2 front engine mounting bolts to the transmission side.
6. Remove the transmission jack. 7. Install the clutch housing cover.

DOWEL PINS

REAR TRANSMISSION

MOUNTING BOLTS
12 x
1.25
mm

105 N·m

(10.5 kg-m, 76 Ib-ft)
TRANSMISSION

JACK

8. Install the release fork in the release hanger, then install the slave cylinder.
9. Install the shift cable and select cable. CAUTION: Take care not to bend the cables.
10. Install the upper cover, change wire bracket and lower cover.
11. Install the upper control arm mounting bolt.

*: Corrosion resistant bolt/nut
8 x
1.25
mm
22 N·m
(2.2 kg-m,

16 Ib-ft)

COTTER PIN
Replace.

6 x 1.0 mm 12 N·m
(1.2 kg-m,

9 Ib-ft)

*8 x
1.25
mm
26 N·m (2.6 kg-m, 19 Ib-ft)
* UPPER CONTROL ARM MOUNTING BOLT

10 x
1.25
mm

60 N·m (6.0 kg-m. 43 Ib-ft)

Corrosion resistant bolt/nut

TRANSMISSION HOUSING

MOUNTING BOLTS
12 x
1.25
mm

65 N·m (6.5 kg-m, 47 Ib-ft)

FRONT ENGINE

MOUNTING BOLT
10 x
1.25
mm

60 N·m (6.5 kg-m, 43 Ib-ft)

8 x
1.25
mm
22 N·m (2.2 kg-m, 16 Ib-ft)

6 x 1.0 mm
12 N·m
(1.2 kg-m,

9 Ib-ft)

10 x
1.25
mm

45 N·m (4.5 kg-m, 33 Ib-ft)

TRANSMISSION HOUSING MOUNTING BOLT
12 x
1.25
mm

65 N·m (6.5 kg-m, 47 Ib-ft)

6 x 1.0 mm
12 N·m (1.2 kg-m, 9 Ib-ft)ProCarManuals.com

Troubleshooting

Anti-lock Brake System Indicator Light

Temporary Driving Conditions:
1. The anti-lock brake system indicator light will come
on and the control unit memorizes the problem
under certain conditions.
NOTE: Problem codes are explained on pages
19 - 46.
The tire(s) adhesion is lost due to excessive cor-
nering speed.
Problem codes: 5, 5-4, 5-8. The vehicle loses traction when starting from a
stuck condition on a muddy, snowy, or sandy

road.
Problem code: 4-1, 4-2, 4-4, 4-8. When the parking brake is applied for more than
30 seconds while the vehicle is being driven.
Problem code: 2. The vehicle is driven on extremely rough road.
The anti-lock brake system is OK, if the anti-lock brake system indicator light goes off after the
engine is restarted.
ANTI-LOCK BRAKE SYSTEM INDICATOR LIGHT
2. If you receive a customer's report that the anti-lock brake system indicator light sometimes comes on,
check the system using the ALB checker to confirm
whether there is any trouble in the system.

See page 19 - 41.

3. The anti-lock brake system indicator light will come on and the control unit will store a problem codewhen there is insufficient battery voltage to the
control unit. An example would be when the bat-
tery is so weak that the car must be jump-started. After the battery is sufficiently recharged, the anti-lock brake system indicator light will work normally
after the engine is stopped and restarted.
However, after recharging the battery, the problem
code must be cleared from the control unit's
memory by disconnecting the ALB 2,3 (No. 32)
fuse for at least 3 seconds. Anti-lock Brake System Indicator Light Circuit:
CAUTION: Use only the digital multimeter to

check the system.

1. The indicator light does not go on when the ignition switch is turned on.
Check the following items. If they are OK, check
the control unit connectors. If not loose or disconnected, install a new control
unit and recheck:
Blown anti-lock brake system indicator light
bulb.
Open circuit in YEL wire between No. 5 (10 A)
fuse and gauge assembly. Open circuit in BLU/WHT wire between gauge
assembly and control unit. Loose component grounding of the control unit
to the body.
2. The anti-lock brake system indicator light remains ON after the engine is started, however the anti-lock brake system indicator light does not blink any
code or sub-code. Check the following items:
Loose or poor connection of the wire harness at

the control unit.

Faulty ALB 2,3 (No. 32) fuse.
Open circuit in WHT/BLK wire between ALB 2,3(No. 32) fuse and control unit.
Open circuit in YEL/BLK wire between fuse No.

4 (1 5 A) and control unit.

Short circuit in BLU/WHT wire between gauge
assembly and control unit. Open circuit in WHT/BLU wire between alter-

nator and control unit.

If the problem is not found substitute a known-good
control unit and recheck whether the warning light re-
mains ON.ProCarManuals.com

Comes on and remains on while running:
1. Stop the engine.
2. Turn the ignition switch on and make sure that the anti-lock brake system indicator light comes on.
3. Restart the engine and check the anti-lock brake system indicator light.
There is no problem in the anti-lock brake system, if the anti-lock brake system indicator light goes off. Go to step 4, if the anti-lock brake system indicator light remains on.

4. Stop the engine.
5. Disconnect the service check connector from the connector cover located under the glove box.
Connect the two terminals of the service check connector with a jumper wire.
6. Turn the ignition switch on, but do not start the engine. 7. Record the blinking frequency of the anti-lock brake system indicator light.
The blinking frequency indicates the problem code.
CAUTION: Before starting the engine, disconnect the jumper wire from the service check connector, or else the
Check Engine light will stay on with the engine running.

Turn the ignition

switch on
PROBLEM CODE:

4– 2

Main Code: 4

Sub-Code: 2
PROBLEM

CODE: 1

Main Code: 1

Sub-Code: none
PROBLEM CODE

7–2

Main Code: 7

Sub-Code: 2

Indicator

light on

Indicator

light off
Connect the

jumper wire
2

Second

pause
1

Second

pause
5 second

pause

5 second

pause

1

Second

pause

1 Second

NOTE:
The control unit can indicate three problem codes (one, two or three problems). If the anti-lock brake system indicator light does not light, see Troubleshooting of Anti-lock Brake System
Indicator Light Circuit page 19-44.
If you miscount the blinking frequency, turn the ignition switch off, then turn on to blink the anti-lock brake
system indicator light again. After the repair is completed, disconnect the ALB 2,3 (No. 32) fuse for at least 3 seconds to erase the control

unit's memory. Then turn the ignition key on again and recheck.
The memory is erased if the connector is disconnected from the control unit or the control unit is removed from
the body. After recording the main and sub-code (if applicable), refer to the Symptom-to-System Chart.

ANTI-LOCK BRAKE SYSTEM INDICATOR LIGHT
SERVICE CHECK CONNECTOR

JUMPER WIREProCarManuals.com

Modulator/Solenoid Unit

Solenoid Leak Test

1. Disconnect the 6-P inspection connector (PNK) from the connector cover located under the glovebox and connect the inspection connector to the
ALB checker.

ANTI-LOCK BRAKE SYSTEM
INDICATOR LIGHT

CONNECTOR

COVER

ALB CHECKER

07HAJ - SG00100 or
07HAJ - SG0010B (US)

07HAJ - SG00200 (Canada)
6-P INSPECTION

CONNECTOR

CAUTION: Place the vehicle on level ground with
the wheels blocked. Put the transmission in neutral
for manual transmission models, and in P for automatic transmission models.
2. Remove the modulator reservoir filter, then fill the modulator reservoir to the MAX level.
NOTE: Do not reuse aerated brake fluid that has
been bled from the power unit.
3. Bleed high pressure fluid from the maintenance bleeder with the special tool.
BLEEDER T-WRENCH

07HAA-SG00100
or

07HAA-SG00101

SOLENOID HEAD
MAINTENANCE
BLEEDER

8 x
1.25
mm
5.5 N·m
(0.55 kg-m,

4.0 Ib-ft)

POWER

UNIT

ACCUMULATOR/
PRESSURE SWITCH
If you can feel back fluid coming from the return
tube, one of the solenoids is leaking. Go to Solenoid Flushing.If you can feel brake fluid coming from the return
tube, one of the solenoids is leaking. Go to step
7.

If you can't feel brake fluid coming from the return tube, the solenoids are OK.
Reinstall the modulator reservoir filter and refill
the reservoir to the MAX level.
7. Bleed high-pressure fluid from the maintenance
bleeder with the special tool, then run through

modes 3 and 6 with the ALB checker. Repeat this

three or four times.

8. Repeat steps 5 and 6. If the solenoid leakage has stopped, reinstall the
modulator reservoir filter and refill the reservoir
to the MAX level. If one of the solenoids is still leaking, replace the
modulator/solenoid
unit.
SOLENOID

RETURN

TUBE
PUMP

SUPPLY

BRAKE

FLUID
SOLENOID RETURN

TUBE
Feel for brake

fluid here.

4. Start the engine and release the parking brake.
5. Turn the Mode Selector to 1 and press the Start Test button.
6. While the pump is running, place your finger over the top of the solenoid return tube in the modulator
reservoir.ProCarManuals.com

Solenoid Flushing
1. Remove the motor relay from the under-hood fuse/relay box. (Location: page 19 - 40)
2. Install the auxiliary window switch (07KAZ — 001000A) into the two motor relay cavities in the
relay box.

MOTOR RELAY

WINDOW SWITCH

07KAZ-001000A

UNDER-HOOD
FUSE/RELAY

BOX

3. Disconnect the four modulator solenoid connec- tors.
4. Bleed any high-pressure fluid from the maintenance bleeder with the Bleeder T-Wrench, then retighten
the bleeder.

BLEEDER T-WRENCH

07HAA - SG00100

or 07HAA - SG00101

SOLENOID HEAD

MAINTENANCE
BLEEDER

8 x
1.25
mm
5.5 N·m
(0.55 kg-m,

4.0 Ib-ft)

POWER

UNIT

ACCUMULATOR/

PRESSURE SWITCH
6. Press the auxiliary switch to run the pump. After
the pump has run for about five seconds, press andrelease the remote starter switch three or four
times to open and close the solenoid. Continue run- ning the pump for about 30 seconds, then release
the auxiliary switch and open and close the solenoid another three or four times.
7. Repeat steps 4-6 for the other two solenoids.
8. Reconnect the solenoids and the pump relay. 9. Connect the ALB Checker and turn the Mode Selec- tor to "1". Start the engine and release the parkingbrake. Push the Start Test button on the ALB

Checker.

10. While the pump is running, place your finger over the top of the solenoid return tube in the modulatorresorvoir and check for leaks. If a solenoid is still leaking, replace the
modulator/solenoid
unit.
REMOTE

STARTER

SWITCH

TO BLK

TERMINAL

TO RED

TERMINAL
FRONT-

RIGHT

FRONT-RIGHT

REAR-LEFT
REAR-RIGHT

5. Connect the RED terminal from one solenoid to the
battery positive (+) terminal with a remote starter
switch. Connect the BLK terminal from the same
solenoid to the battery negative (-) terminal with a
jumper lead as shown.ProCarManuals.com

Bleeding

Air Bleeding with ALB Checker
1. Disconnect the 6-P inspection connecotor (PNK) from the connector cover located under the glovebox and connect the inspection connector to the
ALB checker.
ANTI-LOCK BRAKE SYSTEM
INDICATOR LIGHT

CONNECTOR

COVER

ALB CHECKER

07HAJ - SG00100 or

07HAJ - SG0010B (US)

or

07HAJ-SG00200 (Canada)
6-P INSPECTION

CONNECTOR

CAUTION: Place the vehicle on level ground with
the wheels blocked. Put the transmission in neutral
for manual transmission models, and in P for automatic transmission models.
2. Fill the modulator reservoir to the MAX level.
NOTE: Do not reuse aerated brake fluid that has
been bled from the power unit.
3. Bleed high pressure fluid from the maintenance bleeder with the special tool.
BLEEDER T-WRENCH

07HAA-SG00100

or

07HAA-SG00101

SOLENOID HEAD

ACCUMULATOR/
PRESSURE SWITCH
POWER

UNIT
MAINTENANCE

BLEEDER

8 x
1.25
mm
5.5 N·m
(0.55 kg-m,
4.0 Ib-ft) 7. Install the reservoir cap.

8. Check the anti-lock brake system function in all

modes by using the ALB checker.
MAX

RESERVOIR

CAP

4. Start the engine and release the parking brake.
NOTE: Depress the brake pedal firmly while test in pro-

gress light in ON.

5. There should be at least two strong kickbacks. If not, repeat steps 2 through 5, as necessary.
6. Fill the modulator reservoir up to the MAX level.ProCarManuals.com

Supplemental Restraint System (SRS)
Self-diagnosis Function

The SRS unit includes a self-diagnosis function. If there
is a failure in the sensors, SRS unit, inflator, or their cir-

cuits, the SRS light in the instrument panel goes ON.

SRS INDICATOR LIGHT
As a system check the SRS light also comes on when

the ignition is first turned to the II position. If the light
goes off after approximately 6 seconds, the system is

OK.

If the SRS light remains on (or fails to come on the sys-

tem check mode) one of the SRS components (or the wir-
ing/connectors in-between) is faulty.

Troubleshooting Precautions Always use the test harness. Do not use test
probes directly on component connector
terminals or wires; you may damage them or the
control unit. When connecting any of the test harnesses to the
system, push the connectors straight-in; do not
bend the connector terminals. Before disconnecting any part of the SRS wire
harness, install the short connector (RED) on the airbag. SRS Indicator Light Troubleshooting
Possible conditions: 1. SRS light does not come on at all — see page
23-326.

2. SRS light stays on constantly - see page 23-330.

3. SRS light comes on in combination with a failure of
another electrical system (brake indicator, engine
check light etc.). Check for damage/corrosion at the
dash fuse box.

NOTE:
Before starting the applicable troubleshooting,
check the condition of all SRS connectors and
ground points. If the fault is not found after completing the ap-
plicable troubleshooting, substitute a known-good

SRS unit and check whether the light indication

goes away.
Short connector Installation 1. Disconnect the battery negative cable, then the positive cable.
2. Remove the access panel from the steering wheel, then remove the short connector (RED).
SHORT
CONNECTOR
(RED)

3. Disconnect the connector between the airbag and cable reel, then install the short cconnector (RED)
on the airbag.
Troubleshooting

SHORT CONNECTOR (RED)
AIRBAG CONNECTOR

CABLE REEL

CONNECTOR
ACCESS

PANELProCarManuals.com