1991 ACURA NSX reset

Disassembly

NOTE:
Handle the terminals and printed circuit boards carefully to avoid damaging them.
Replace
the
speedometer,
trip
meter,
and
printed
circuit
board
A as a
unit
if any of
them
is
faulty. Replace the tachometer, odometer, and printed circuit board B as a unit if any of them is faulty.

SPEEDOMETER MOUNTING SCREWS (x3) TACHOMETER MOUNTING SCREWS (x3)
VOLTAGE/FUEL GAUGE
MOUNTING SCREWS (x5) ENGINE COOLANT TEMP./ENGINE OIL PRESSURE
GAUGE MOUNTING SCREWS (x6)
HOUSING
ENGINE COOLANT

TEMPERATURE/

ENGINE OIL PRESSURE GAUGE

Test, page 23-136 and 137

SAFETY INDICATOR
MOUNTING SCREWS (x2) SHIFT INDICATOR
TACHOMETER

Specification, page 23-121
A/T GEAR POSITION
INDICATOR

See page 23-152 ('94-'96) ('91-'93)


LIGHT HOUSING
ODOMETER
SPEEDOMETER

Specification, page 23-121

TRIP METER FUEL/VOLTAGE GAUGE

Test, page 23-121

and 134

FACE PANEL PRINTED CIRCUIT
BOARD B
BOARD-TO-BOARD

CONNECTOR

PRINTED CIRCUIT
BOARD COVER
PRINTED CIRCUIT
BOARD A
SAFETY INDICATOR

See page 23-145 ('93-'96)('91-'92)

TRIP METER
RESET BUTTON
VISORProCarManuals.com

Cylinder Heads
Installation (cont'd)
Rear:
8 x
1.25
mm
22 N .
m
(2.2 kg-m,
16 Ib-ft)

HEATED OXYGEN

SENSOR

45 N .
m
(4.5 kg-m,
33 Ib-ft) Be careful not to damage.

GASKET
Replace.

REAR EXHAUST
MANIFOLD

EXHAUST

MANIFOLD

COVER
SELF LOCKING NUTS
8 x
1.25
mm

34 N .
m
(3.4 kg-m,

25 Ib-ft)

Replace.

3. Install the cylinder heads on the engine block. The cylinder head dowel pins and the head oil con-
trol orifice must be aligned.

CYLINDER HEAD

GASKET (METAL)
Replace.
CYLINDER HEAD

GASKET (METAL)

Replace.

HEAD ORIFICES

DOWEL

PIN

DOWEL PIN
O-RING
Replace.
DOWEL

PINS
CYLINDER HEAD BOLTS

11 x 1.5 mm

78 N .
m (7.8 kg-m. 56 Ib-ft)

Apply clean engine oil to the bolt threads and washer contact

surfaces.

CYLINDER HEAD BOLTS TORQUE SEQUENCE

Specified Torque

11 x 1.5 mm

78 N .
m (7.8 kg-m, 56 Ib-ft)
NOTE: We recommend using a beam-type torque
wrench. When using a preset-type torque wrench,
be sure to tighten slowly and not to over-tighten.
Always use a new cylinder head gasket. Apply clean engine oil to the bolt threads and
washer contact surfaces.
4. Tighten the cylinder head bolts sequentially in two
or three steps.ProCarManuals.com

II. ENGINE CONTROL MODULE (ECM) Reset Procedure

1. Turn the ignition switch off.

2. Remove the CLOCK (7.5 A) fuse from the under-hood fuse/relay box for 10 seconds to reset ECM.

NOTE: Disconnecting the CLOCK fuse also cancels the radio preset stations and the clock setting. Make note of

the radio presets before removing the fuse so you can reset them.

III. Final Procedure (this procedure must be done after any troubleshooting)

1. Remove the Jumper Wire.

NOTE: If the Service Check Connector is jumped, the MIL will stay on.

2. Do the ECM Reset Procedure.

3. Set the radio preset stations and the clock setting.

(cont'd)
CLOCK

(7.5 A) FUSE

UNDER-HOOD

FUSE/RELAY BOXProCarManuals.com

How to Read Flowcharts

A flowchart is designed to be used from start to final repair. It's like a map showing you the shortest distance. But

beware: if you go off the "map" anywhere but a "stop" symbol, you can easily get lost.

(bold type)

(bold type)
Describes the conditions or situation to start a troubleshooting flowchart.

Asks you to do something; perform a test, set up a condition etc.

Asks you about the result of an action, then sends you in the appropriate troubleshooting direction.

The end of a series of actions and decisions, describes a final repair action and sometimes directs you

to an earlier part of the flowchart to confirm your repair.

NOTE:

The term "Intermittent Failure" is used in these charts. It simply means a system may have had a failure, but it checks

out OK at this time. If the Malfunction Indicator Lamp (MIL) on the dash does not come on, check for poor connections

or loose wires at all connections related to the circuit that you are troubleshooting (see illustration below).

Most of the troubleshooting flowcharts have you reset the Engine Control Module (ECM) and try to duplicate the Diag-

nostic Trouble Code (DTC). If the problem is intermittent and you can't duplicate the code, do not continue through

the flowchart. To do so will only result in confusion and, possibly, a needlessly replaced ECM.

"Open"
and
"Short"
are
common electrical terms.
An
open
is a
break
in a
wire
or at a
connection.
A
short
is an

accidental connection of a wire to ground or to another wire. In simple electronics, this usually means something won't

work at all. In complex electronics (like ECM's), this can sometimes mean something works, but not the way it's sup-

posed to.

If the electrical readings are not as specified when using the test harness, check the test harness connections before

proceeding.

TIGHT

LOOSEProCarManuals.com

Idle Control System
Troubleshooting Flowchart

Alternator (ALT) FR Signal
This signals the ECM when the alternator is charging.
Inspection of ALT FR signal.
Connect the test harness be-
tween the ECM and connector.
Disconnect "D" connector from
the engine wire harness only, not
the ECM (see page 11-37).

Turn the ignition switch ON.

Measure voltage between D9 ( + ) terminal and A26 (-) ter-
minal.
Is there approx. 5 V?
Turn the ignition switch OFF.
Reconnect "D" connector to the
engine wire harness.
Warm up engine to normal oper-ating temperature (the cooling
fan comes on).
Measure voltage between D9( + ) terminal and A26 (-) ter-
minal.

Does the voltage decrease when

headlights and rear defogger are

turned on ?

Do the ECM Reset Procedure
(see page 11-35).
ALT FR signal is OK.(To page 11-93) Substitute a known-good ECM

and recheck. If prescribed

voltage is now available, replace
the original ECM.
Turn the ignition switch OFF.ProCarManuals.com

6. Turn the ignition switch OFF.

7. Reconnect the 2P connector on the IAC valve, then

remove CLOCK fuse in the under-hood fuse/relay

box for 10 seconds to reset ECM.

8. Restart and idle the engine with no-load conditions

in which the headlights, blower fan, rear defogger,

cooling fan, and air conditioner are not operating

for one minute, then check the idle speed.

Idle speed should be:

M/T

A/T
800
50 rpm

750
50 rpm

(in or range)ProCarManuals.com

Troubleshooting Procedures

When the Transmission Control Module (TCM) senses an abnormality in the input or output systems, the indicator
light in the gauge assembly will blink. However, when the Service Check Connector (located to the lower right of the glove compartment) is connected with a jumper wire, the indicator light will blink the Diagnostic Trouble Code (DTC)

when the ignition switch is turned on.

When the indicator light has been reported on, connect the two terminals of the Service Check Connector together.
Then turn on the ignition switch and observe the indicator light.
Codes 1 through 9 are indicated by individual short blinks. Codes 10 through 16 are indicated by a series of long and
short blinks. One long blink equals 10 short blinks. Add the long and short blinks together to determine the code. After
determining the code, refer to the electrical system Symptom-to-Component Chart on page 14-52 and 53. SERVICE CHECK
CONNECTOR
Connect with jumper wire.

INDICATOR
Some PGM-FI problems will also make the indicator light come on After repairing the PGM-FI system, disconnect the
CLOCK fuse (7.5 A) in the main relay box for more than 10 seconds to reset the TCM memory.
long short
See DTC 1

See DTC 2

See DTC 14

LIGHT

short
PGM-FI system
The PGM-FI system on this model is a sequential multiport fuel injection system. Disconnecting the CLOCK fuse also cancels the radio preset stations and the clock setting. Make note of the radio
presets before removing the fuse so you can reset them.

NOTE:ProCarManuals.com

If the inspection for a particular DTC requires the use of Test Harness (07LAJ—PT3010A):
Connect the wire harness to the Test Harness, and/or connect the Test Harness to the TCM according to the

troubleshooting flowchart.

TCM

TEST HARNESS

Terminal Locations

TCM Reset Procedure

Turn the ignition switch off. -

, Remove the CLOCK fuse (7.5 A) from the main relay box for 10 seconds to reset the TCM.

1

2

NOTE: Disconnecting the CLOCK fuse also cancels the radio preset stations and the clock setting. Make note of the
radio presets before removing the fuse so you can reset them.
Final Procedure NOTE: This procedure must be done after any troubleshooting.
1. Remove the jumper wire from the Service Check Connector.
2. Reset the TCM. 3. Set the radio preset stations and clock setting.
Only the A and D terminals of the Test Harness are used for A/T troubleshooting.

Unless otherwise noted, use only the Digital Multimeter, KS—AHM —32—003, for testing.

07LAJ-PT3010A

NOTE:ProCarManuals.com