clock reset ACURA NSX 1991 Service Repair Manual

II. Engine Control Module (ECM) Reset Procedure

Either of the following actions, will reset the ECM.

• Using the OBD-II scan tool or Honda PGM Tester to clear the ECM's memory.

NOTE: See the OBD-II scan tool or Honda PGM Tester user's manuals for specific operating instructions.

• Turn the ignition switch OFF. Remove the CLOCK (7.5 A) fuse from the under-hood fuse/relay box for 10 seconds.

UNDER-HOOD

FUSE/RELAY BOX
CLOCK

(7.5 A) FUSE

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

1. Remove the SCS Service Connector if it is connected.

NOTE: If the SCS service connector is connected and there are no DTCs stored in the ECM, the MIL will stay on

when the ignition switch is turned on.

2. Do the ECM Reset Procedure.

3. Turn the ignition switch OFF.

4. Disconnect the OBD-II scan tool or Honda PGM Tester from the Data Link Connector,ProCarManuals.com

Preset Torqu e
Inspectio n
On-Car:
1 . Bloc k th e fron t wheels .
2 . Shif t t o low gear .
3 . Lif t u p rea r wheels , an d plac e th e safet y stan d (Lif t
an d Suppor t Points , se e sectio n 1 ).
4 . Measur e prese t torqu e clockwis e usin g a torqu e
wrenc h a s shown .
Standard: 120-280 N-m (12-28 kg-m,
87-20 3 Ib-ft )
Servic e Limit : 6 0 N- m (6 kg-m , 4 3 Ib-ft )
TORQU E WRENC H
RIGH T REA R WHEE L
SAFETY STAN D
5. I f prese t torqu e is les s tha n th e servic e limit , replac e
th e limite d sli p differentia l clutc h set .
NOTE : Adjus t th e 6 5 m m (differentia l housin g cove r
side ) an d 11 2 m m (differentia l housin g cove r side )
shim s wheneve r th e clutc h se t i s replaced . Assembly
:
Plac e on e specia l too l i n a vise . Plac e th e lef t sid e
o f th e differentia l assembl y o n th e specia l tool , the n
prese t th e differentia l wit h 3- 5 rotations , counter -
clockwise .
DIFFERENTIA L
INSPECTIO N TOOL S
07MAJ-PR90100
2. Measur e prese t torqu e counterclockwis e usin g a tor -
qu e wrenc h a s shown.
Standard :
60-140 N- m (6-1 4 kg-m ,
43-10 1 Ib-ft )
Servic e Limit : 3 0 N- m (3 kg-m , 2 2 Ib-ft )
TORQU E WRENC H
DIFFERENTIA L
INSPECTIO N TOOL S
07MAJ-PR90100
3 . I f prese t torqu e is les s tha n th e servic e limit , replac e
th e limite d sli p differentia l clutc h set .
NOTE : Adjus t th e 6 5 m m an d 11 2 m m shim s
wheneve r th e clutc h se t i s replaced .
ProCarManuals.com

Preset Torque

Inspection
On-Car:

1. Lift up right rear wheel,
and place the safety stand.

(Lift and Support Points, see section 1).
2. Block the other three wheels.
3. Measure preset torque clockwise using a torque wrench as shown.

Standard:
60–140 N·m

(6–14 kg-m, 43–101 Ib-ft)

Service Limits: 30 N·m (3 kg-m, 22 Ib-ft)

TORQUE WRENCH
RIGHT REAR WHEEL SAFETY STAND

4. If preset torque is less than the service limit, replace the clutch discs with new ones.
NOTE: Adjust the thrust shim whenever the clutch
discs are replaced (see page 15-22).
Assembly:

1. Place one special tool in a vise. Place the left side of the differential assembly on the special tool, then
preset the differential with 3 – 5 rotations, both
clockwise and counterclockwise.

DIFFERENTIAL
INSPECTION TOOLS

07MAJ– PR90100

2. Measure preset torque clockwise using a torque wrench as shown.

Standard: 60–140 N·m
(6–14 kg-m, 43–101 Ib-ft)

Service Limit: 30 N·m (3 kg-m, 22 Ib-ft)

TORQUE WRENCH
DIFFERENTIAL
INSPECTION TOOLS

07MAJ – PR90100

3. If preset torque is less than the service limit, replace the clutch discs with new ones.
NOTE: Adjust the thrust shim whenever the clutch

discs are replaced (see page 15-22).
ProCarManuals.com

Troubleshooting Precautions

EPS Indicator Light

Under normal conditions, the EPS indicator light in the gauge assembly comes on when the ignition switch is turned to

the ON (II) position, then goes off after the engine is started. This indicates that the bulb and its circuits are operating cor-

rectly. If there is any trouble in the system, the EPS indicator light turns on during driving, and the power steering assist is

turned off. When the EPS indicator light comes on, the control unit memorizes the DTC. In this case, the control unit does

not activate the EPS system after the engine starts again but it keeps the EPS indicator light on.

Diagnostic Trouble Code (DTC)

• The lowest DTC is indicated first.

• The DTCs continue blinking until the ignition switch is turned off.

• The DTCs are erased from the control unit when the EPS control unit VBU power supply or connector is disconnected.

• The EPS system can be reset and the control unit's memory can be erased by disconnecting the CLOCK (7.5 A) fuse for

more than ten seconds.

Self-diagnosis:

The CPU (central processing unit) controls the following when it detects a problem during self-diagnosis:

1. Turns the EPS indicator light ON to alert the driver.

2. Power assist stops, and normal manual steering operation resumes (except DTC 21 and DTC 33).

3. The EPS control unit memorizes the diagnostic trouble code (DTC).

4. After the DTC is stored in the control unit, the CPU stops self-diagnosis.

Troubleshooting:

• Before starting the troubleshooting, clear the DTC by disconnecting the CLOCK (7.5 A) fuse for ten seconds or more,

and test-drive the car. Check that the symptom of the trouble appears again, and then troubleshoot. If the problem is an

intermittent problem, the system does not become active after the engine starts even though the problem is solved.

• When both EPS indicator light and A/T "D" indicator light come on, perform the A/T troubleshooting first.

• When the customer's reported problem cannot be verified in the car, ask the customer about the conditions when the

EPS indicator light came ON, then test-drive the car under those conditions, if possible. If the EPS indicator light does

not come ON during the test, check for loose connections or poor contacts at the connectors by wiggling the harness,

etc.

• The connector terminal numbers are viewed from the wire side for the female terminals and from the terminal side for

the male terminals.

• After the repair, test-drive the car and check that the EPS indicator light does not come ON again during the test. (Refer

to the Symptom-to-System Chart for diagnostic period.)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

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

If a customer describes the symptoms for codes 3, 6, 11, 14 or 1 5 yet the indicator light is not blinking, it will
be necessary to recreate the symptom by test driving, and then checking the indicator light with the ignition

still
ON.
If the indicator light displays codes 1,2,3,8, 11, or 16, check first the No. 9, 13 and 18 and fuse before elec-
trical troubleshooting.
If any of the fuses have blown, repair them and then recheck. If the indicator light displays codes other than those listed above or stays lit continuously, the TCM is faulty.
Sometimes the indicator light and the Malfunction Indicator Lamp (MID/Check Engine light may come on
simultaneously. If so, check the PGM-FI system according to the number of blinks on the MIL/Check Engine light,
then reset the memory by removing the CLOCK fuse in the main relay box for more than 10 seconds. Drive the vehicle for several minutes at speed over 30 mph (50 km/h), then recheck the MIL/Check Engine light.PGM-FI system

The PGM-FI system on this model is a sequential multiport fuel injectin system.
The indicator light may comes on, indicating a system problem, when, in fact, there is a poor or intermittent
electrical connection. First, check the electrical connections, clean or repair connections if necessary.If the electrical readings are not as specified when using the test harness, check the test harness connections
before proceeding.
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. If the self-diagnosis indicator light does not blink, perform an inspection according to the table listed below.
Symptom
• Lock-up clutch does not
engage.

• Transmission jerks hard when shifting.
• Transmission jerks hard when
shifting.

• Transmission jerks hard when
shifting

• Lock-up clutch does not

engage.
14-7214-70 14-68
14-67

Refer to

page

Possible Cause
• Disconnected gauge assembly connector
• Short or open in tachometer wire
• Faulty tachometer
• Short or open in FAS (PNK) wire between D16 terminal and

ECM.

• Trouble in ECM
• Disconnected mainshaft speed sensor connector
• Short or open in mainshaft speed sensor wire
• Faulty mainshaft speed sensor
• Disconnected linear solenoid connector
• Short or open in linear solenoid wire
• Faulty linear solenoid
Blinks

OFF

OFF

OFF

When the ignition

switch is turned on,
indicator light
Number of indicator light

blinks while Service CheckConnector is jumped.

11

14

15

16


Ref.page

14-74
14-76
14-77
14-78
NOTE:ProCarManuals.com

Troubleshooting

Diagnostic Trouble Code (DTC) Display

When the service check connector terminals are connected with a jumper wire, the EPS control unit blinks the EPS indi-
cator light to indicate the DTC. The DTC is indicated by a series of long and short blinks. One long blink equals 10 shortblinks. Add the long and short blinks together to determine the DTC, then refer to the Troubleshooting Chart on page 17-51.

Example 1.3 seconds
0.28 seconds
1.3 seconds

0.36 seconds
The control unit can memorize any number of simultaneous problems. The DTC is repeated sequentially beginning with
the lowest number.
The DTC is stored in the control unit memory even when the ignition switch is turned off. After repairing the EPS system,
disconnect the CLOCK fuse in the relay box for more than 10 seconds to reset the EPS control unit memory.ProCarManuals.com