Inmuui

ATOJt*

0.5 seconds 4.5 seconds o^JujiiijC

1.5 seconds

2.5 seconds

Diagnostic code

(a) If system is operating normally (no malfunction), the light will blink once every 0.25 seconds.

(b) In event of a malfunction, the light will blink once every 0.5 seconds. The first number of blinks will equal the first digit of a 2-digit diagnostic code. After 8 1.5 second pause, the 2nd number of blinks will equal the 2nd number of a 2-digit diagnostic code. If there are two or more codes, there will be a 2.5 seconds pause between each.

NOTE : In event of a number of troubles codes, indication will begin from the smaller value and continue to the larger in order.

4. After the diagnosis check, remove the sub-wire from the check connector.

STOP 15A

tiottt

Cancelling out diagnostic code

(a) After repair of the trouble area, the diagnostic code retained in memory by the ECU must be cancelled out by removing the STOP fuse (15A) for 30 seconds or more, depending on ambient temperature {the lower the temperature, the longer the fuse must be left out) with the ignition switch off.

NOTE:

• Cancellation can also be done by removing the battery negative ( —) terminal, but in this case other memory systems (radio ETR, clock, etc.) will also be cancelled out.

• If the diagnostic code is not cancelled out. it will be retained by the ECU and appear along with a new code in event of future trouble.

• If it is necessary to work on engine components requiring removal of the battery terminal, a check must first be made to see if a diagnostic code is detected.

(b) After cancellation, perform a road test, if necessary, confirm that a "normal" code is now read on the "CHECK ENGINE" warning light.

If the same diagnostic code is still indicated, it indicates that the trouble area has not been repaired thoroughly.

DIAGNOSIS INDICATION

(1) Including "Normal", the ECU is programmed with the following 16 diagnostic codes.

(2) When 2 or more codes are indicated, the lowest number (code) will appear first.

However, no other code will apear along with code No. 11.

(3) All detected diagnostic codes, except 51 and 53, will be retained in memory by the ECU from the time of detection until cancelled out.

(4) Once the malfunction is cleared, the "CHECK ENGINE" warning light on the instrument panel will go out but the diagnostic code(s) remain stored in ECU memory (except for code 51).

Code No.

Light Pattern

Code No.

Light Pattern

-

z jmuuuul

31

juuul

n

jul

32

juuuul

12

juul

41

juuuul

13

jliuul

42

juuuuul

14

jlfuulll

43

juuuuuul

21

juul •

51

juuuuul

22

juuul

52

juuuuuul

23

juuuul

53

juuuiuuul

Code No.

System

Diagnosis

Trouble Area

See page

Normal

This appears when none of the other codes (11 thru 51» are identified.

11

ECU ( + B)

Wire severence. however slight, in ♦ B (ECU).

1. Main relay circuit

2. Mam relay

3. ECU

Fl 32

12

RPM Signal

No No, G signal to ECU within several seconds after engine is crankcd.

1 Distributor circuit

2. Distributor

3. Starter signal circuit

4. ECU

IG-7

13

RPM Signal

No Ne signal to ECU within several seconds after engine roaches 1.000 rpm.

Same as 12. above.

14

Iflniiion Signal

No signal from igniter six times in succession

2. Igniter

3. ECU

FI-42

21

Oxygen Sensor Signal

Oxygen sensor gives a lean signal for several seconds even when coolant temperature is Above 50°C (122°F) and engine is running under high k>8d conditions above 1,500 rpm.

1. Oxygen sensor circuit

2. Oxygen sensor

3. ECU

FI-73

Code No.

System

Oiagnosis

Trouble Area

See page

22

Water Temp. Sensor Signal

Open or short circuit in coolant temp, sensor signal.

1. Water temp, sensor circuit

2. Water temp, sensor

3. ECU

FI-72

23

Intake Air Temp. Sensor Signal

Open or short circuit in intake air temp, sensor.

1. Intake air temp, sensor circuit

2. Intake air temp, sensor

3. ECU

Fl 38

31

Air Flow Meter Signal

Open circuit in Vc signal or Vs and E2 short circuited when idle points are closed.

1. Air flow meter circuit

2. Air flow meter

3. ECU

FI-37

32

Air Flow Meter # Signal

Open circuit in E? or Vc and Vs short circuited.

Same as 31, above.

FI-37

41

Throttle Position Sensor Signal

Open or short circuit in throttle position sensor signal.

1. Throttle position sensor circuit

2. Throttle position sensor

3. ECU

FI-35

42

Vehicle Speed Sensor Signal

(A/T): Signal informing ECU that vehicle speed is 2.0 km/h or less has been input ECU for 5 seconds with engine running at 2,500 rpm or more and shift lever is in other than N or P range.

(M/T): Signal informing ECU that vehicle speed is 2.0 kmfh or less has been input ECU for 5 seconds with engine running at 2,500 rpm or more.

1. Vehicle speed sensor circuit

2. Vehiclo speed sensor

3. Torque converter slipping

4. ECU

43

Starter Signal f+ B>

No STA signal to ECU when engine is running over 800 rpm.

1. Main relay circuit

2. IG switch circuit (starter)

3. IG switch

4. ECU

FI-40

51

Switch Signal

Neutral start switch OFF or air conditioner switch ON during diagnostic check.

1. Neutral start S/W

3. ECU

52

Knock Sensor Signal

Open or short circuit in knock sensor.

1. Knock sensor circuit

2. Knock sensor

3. ECU

53

Knock Sensor Signal

Faulty ECU. (KNOCK CPU)

ECU

INSPECTION OF DIAGNOSIS CIRCUIT

STOP Fuîe

EFI Fuse f-cKo-

No. 1 Main Relay

Fusible [Link r

I Battery i

Ignition S/W

Check Engine Warning Light

Cheek Conncctor ~

9 OtU

Does CHECK ENG warning light come on when

YES

System Normal

ignition switch is at ON?

NO

Does CHECK ENG. light come on when ECU terminal W is grounded to the body?

YES

Check wiring between ECU terminal E^ and body ground

Tbad

OK

NO

Check bulb, fuse and wiring between ECU and ignition switch.

Repair or replace

Try another ECU

Repair or replacej

Does CHECK ENG. warning light go OFF when

YES

System Normal

engine is started?

Check wiring between ECU and CHECK ENG. warning light.

J OK

Repair

1$ there diagnosis code output when service, connector is short circuited?

Does CHECK ENG. warning light go out after repair according to malfunction code?

Try another ECU

Further repair required

System OK

Cancel out Diagnostic code

FI-28

EFI SYSTEM

— Troubleshooting with Volt/Ohmmeter

TROUBLESHOOTING WITH VOLT/OHMMETER

PREPARATION FOR TROUBLESHOOTING

1. Remove the glove box door and glove box.

2. Remove the ECU with wire harness.

EFI SYSTEM CHECK PROCEDURE

NOTE:

1. The EFI circuit can be checked by measuring the resistance and voltage at the wiring connectors of the ECU.

2. Perform all voltage measurement with the connectors connected.

3. Verify that the battery voltage is 11V or above when the ignition switch is ON.

Using a voltmeter, measure the voltage at each terminal of the wiring connector.

NOTE: If there is any problem, see TROUBLESHOOTING

FOR EFI ELECTRONIC CIRCUIT WITH VOLT/ OHMMETER.

Connectors of ECU

Symbol

Terminal Name

Symbol

Terminal Name

Symbol

Terminal Name

Eoi

ENGINE GROUND

G6

ENGINE REVOLUTION SENSOR

A/C

A/C MAGNET SWITCH

Eo?

ENGINE GROUND

Vf

CHECK CONNECTOR

SPD

SPEEDOMETER

No. 10

INJECTOR

G

ENGINE REVOLUTION SENSOR

W

WARNING LIGHT

No.20

INJECTOR

T

CHECK CONNECTOR

THA

AIR TEMP. SENSOR

STA

STARTER SWITCH

VTA

THROTTLE SWITCH

Vs

AIR FLOW METER

IGt

IGNITER

Ne

ENGINE REVOLUTION SENSOR

Vc

AIR FLOW METER

EGR

EGR VSV

IDL

THROTTLE SWITCH

BAT

BATTERY +B

Ei

ENGINE GROUND

KNK

KNOCK SENSOR

IG S/W

IGNITION SWITCH

N/C

NEUTRAL START SWITCH (A/T)

IGf

IGNITER

+ B

MAIN RELAY

CLUTCH SWITCH IM/T)

Ox

OXYGEN SENSOR

TCD

ECT COMPUTER

ISCi

ISC MOTOR NO. 1 COIL

THW

WATER TEMP. SENSOR

OIL

OIL PRESSURE SWITCH

ISC2

ISC MOTOR NO. 2 COIL

E2

SENSOR EARTH

Li

ECT COMPUTER

ISCi

ISC MOTOR NO.3 COIL

Ei

ENGINE GROUND

Li

ECT COMPUTER

ISC«

ISC MOTOR NO.4 COIL

M-REL

MAIN RELAY COIL

L]

ECT COMPUTER

1 '—'

1 --» 1

>-» 1

Eo,

No. 10

STA

EGR

N/C

ISC J

ISC 2

GO

G

Ht

IG»

THW

I,

L>

L>

RËL

SPD

THA

V*

Vc

BAT

SAV

Eo,

No. 20

IGt

E,

ISC 3

ISC 4

VF

T

VTA

IDL

KNK

Ox

E,

Ej

Ei

TOO

A/C

W

OIL

♦ B

TROUBLESHOOTING FOR EFI ELECTRONIC CIRCUIT WITH VOLT/OHMMETER

NOTE: Because the following troubleshooting procedures are designed for inspection of each separate system, the actual troubleshooting procedure may vary somewhat. However, please refer to these procedures and perform actual troubleshooting, conforming to the inspection methods described in this manual.

For example, it is better to first make a simple check of the fuses, fusible links and connecting condition of the connectors before making your inspection according to the procedures listed.

VOLTAGES AT ECU WIRING CONNECTORS

No.

Terminals

Condition

STD Voltage

See page

BAT - Ei

FI-32

1

+ B - Ei

10 - 14

F1-33

IG S/W - Ei

M-REL - Ei

FI-34

IDL - Ez

Throttle valve open

4-6

FI-35

9

Vc - Ej

4-6

VTA - E?

Throttle valve fully closed

0.1 - 1.0

FI-36

IG S/W ON

Throttle valve fully opened

4-5

Vc - 6?

4-6

FI-37

Measuring plate fully closed

4-6

O

Vs - Ei

Measuring plate fully open

0.02 - 0.08

FI-38

o

Idling

2-4

3,000 rpm

0.3 - 1.0

THA - Ei

IG S/W ON

Intake air temperature 20°C (68°F>

1 - 2

FI-38

4

THW - Ei

Coolant temperature 80°C <176°F)

0.1 - 0.5

FI-39

5

STA - Et

IG S/W ST position

6-12

F1-40

6

No. 10 No. 20

IG S/W ON

9-14

F1-41

7

K3t - Ei

Cranking or Idling

0.7 - 1.0

F1-42

I - Ei ISC4

IG S/W ON

9-14

FI-43

2 — 3 sees, after engine off

9-14

INSPECTION OF WIRING CONNECTOR LINE MEASURE RESISTANCE OF ECU CAUTION:

1. Do not touch the ECU terminals.

2. The tester probe should be inserted into the wiring connector from the wiring side.

Using an ohmmeter, check the resistance between each terminal of the wiring connector.

• Disconnect the wiring connectors from the ECU.

• Measure the resistance between each terminal of the wiring connectors.

Resistances at ECU Wiring Connectors

Terminals

Condition

Resistance (0)

IDL - Ei

Throttle valve open

00

Throttle valve fully closed

0 - 100 n

VTA - E*

Throttle valve fully opened

3.300 - 10,000

Throttle valve fully closed

200 - 800

Vc - Ei

Disconnect air flow meter connector

3,000 - 7,000

Disconnect throttle position sensor connector

200 - 400

Vs - E*

Measuring plate fully closed

20 - 400

Measuring plate fully opened

20 - 1,000

THA - E?

Intake air temperature 20°C (68°F)

2,000 - 3,000

G -G©

140 - 180

Ne - G©

140 - 180

ISC., ISC2 ISC*. ISC«

ECU Connector

No.

Terminals

Trouble

Condition

STD Voltage

BAT - Ei

No voltage

10 - 14

1

+ B - Ei

No voltage

Ignition switch ON

10 - 14

IG S/W - Ei

No voltage

Ignition switch ON

10 - 14

M-REL - Ei

No voltage

Ignition switch ON

10 - 14

• BAT ~ Ei

Voltmeter

FKJ744

Ohmmeter

• +B " Ei

0 There is no voltage between ECU terminals + B and Ei. UG S/W ON)

(g) Check that there is voltage between ECU terminal + B and body ground. (IG S/W ON)

Chock wiring between ECU terminal Ei and body ground.

Repair or replace

Check fuse and wiring harness.

Repair or replace

Check NO. 1 main relay.

Replace

• IG S/W - Ei

® There is no voltage between ECU terminals KS S/W and Ei. (IG S/W ON)

(2) Check that there is voltage between ECU terminal IG S/W and body ground. (IG S/W ON)

NO OK

Check wiring between ECU terminal Ei and body ground.

Repair or replace

Check fusible links and ignition switch.

NO

Repair or replace

*K)74S

Voltmeter ft} 74 J

Voltmeter ft} 74 J

0 There is no voltage between ECU terminals M-REL and Ei.

0 There is no voltage between ECU terminals M-REL and Ei.

(2) Check that there is voltage between ECU terminal M-REL and body ground. (K3 SAW ON)

NO J OK

Check wiring between ECU terminal Ei and body ground.

Repair or replace

Check NO. 1 main relay and wiring harness.

BAD

Replace

J OK

Try another ECU.

No.

Terminals

Trouble

Condition

STD voltage

IOL - E2

Throttle valve open

4-6

VTA - E2

No voltage

Ignition

Throttle valve fully closed

0.1 - 1.0

2

switch ON

Throttle valve fully open

4-5

Vc - Ei

4-6

0 There is no voltage between ECU terminals IDL and E2. (IG S/W ON) «Throttle valve open)

(2) Check that there is voltage between ECU terminal +B body and body ground. <KS S/W ON)

NO OK

Check wiring between ECU terminal Ei and body ground.

J BAD

Repair or replace

Repair or replace

Try another ECU.

Voltmeter

Check wiring between ECU terminal Ei and body ground.

Repair or replace

Repair or replace

@ Check throttle position sensor.

Repair or replace

Check wiring between ECU throttle position sensor.

Voltmeter

® There is no specified voltage at ECU terminals VTA and £2. (IG S/W ON)

(2) Check that there is voltage between ECU terminal + B and body ground. (KS S/W ON)

Try another ECU.

Repair or replace

Repair or replace

Check wiring between ECU terminal Ei and body ground.

Check wiring between ECU throttle position sensor.

Repair or replace

@ Check throttle position sensor.

Repair or replace

FOS41

Voltmeter

Voltmeter i

f»0S41

No.

Terminal

Trouble

Condition

STD Voltage

Vc - E2

Ignition S/W ON

4 - 6 V

V» - Ei

Measuring plate fully closed

4 - 5 V

3

Vs - E2

No voltage

Measuring plate fully open

0.02 - 0.08 V

Vs - Ej

Idling

2-4 V

V« - Ez

3.000 rpm

0.3 - 1.0 V

THA - E»

IG S/W ON

Intake air temperature 20°C (68°F)

1 - 2 V

Air Flow Meter ECU

*—o-

Vs Vc THA

E,

Lo-

J

1

1

1

r

• Vc Ea

© There is no voltage between ECU terminals Vc and E?. (IG S/W ONI

(D Check that there is voltage between ECU terminal + B and body ground. (IG S/W ONI

NO OK

(3) Check wiring between ECU terminal E2 and body ground.

BAD

Repair or replace

OK

Try another ECU.

Ohmmeter ECU

F K>750

Ohmmeter ECU

F K>750

rtana

(T) There is no specified voltage at ECU terminals Vs and E2. (IG S/W ON)

Check that there is voltage between ECU terminal + B and body ground. (IG S/W ON)

NO OK

Check wiring between ECU terminal E? and body ground.

Repair or replace

THA - E2

Voltmeter

Condition

STD Voltage

Terminals

Replace water temp, sensor.

Try another ECU.

Check wiring between ECU and water temp, sensor.

Repair or replace wiring.

There is no voltage between ECU terminals THW and E*.

Check that there is voltage between ECU terminal + B and body (IG S/W ON)

Condition

STD Voltage

No voltage

Ignition switch ON

Coolant temperature 80°C (176°F)

Terminals

Trouble

Water Temp. Sensor

Voltmeter

Voltmeter

Terminals

Trouble

Condition

STD Voltage

No voltage

Ignition switch ST position

J Battery

Neutral Start S/W (For A/T)

Cold Start Injector

Starter

Starter

Circuit Opening Relay i

ECU STA

Voltmeter

Voltmeter

Starter
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