MSA5TCD95S 11 fuel injection

1 Radiator main fan2 Radiator sub fan 10 Fuel pump modulator 11 Roll over valve 12 Purge control solenoid valve 13 Canister 14 Throttle sensor 15 Auxiliary air control valve 16 By-pass a

SVX

1992

Precaution for Supplemental Restraint System

"Airbag"

The Supplemental Restraint System "Airbag"

helps to reduce the risk or severity of injury to the

driver in a frontal collision

The Supplemental Restraint System consists of

an airbag module (located in the center of the

steering wheel), sensors, a control unit, warning

light, wiring harness and spiral cable

Information necessary to service the safety is

included in the "5-5 SUPPLEMENTAL

RE-STRAINT SYSTEM" of this Service Manual

WARNING :

To avoid rendering the Airbag system

inoper-ative, which could lead to personal injury or

death in the event of a severe frontal collision,

all maintenance must be performed by an

authorized SVX dealer

Improper maintenance, including incorrect

re-moval and installation of the Airbag system,

can lead to personal injury caused by

uninten-tional activation of the Airbag system

All Airbag system electrical wiring harnesses

and connectors are covered with yellow outer

insulation Do not use electrical test equipment

on any circuit related to the Supplemental

Restraint System "Airbag"

T+~++

2-7

M MECHANISM AND FUNCTION .,

1 General ,

2 Air Line

3 Fuel Line .

4 Induction Control System .,

5 Sensor and Switch

6 Control System .

7 Self-diagnosis System

C COMPONENT PARTS

1 Intake Manifold and Collector

2 Air Intake Boot and Throttle Body

3 Air Cleaner

T TROUBLESHOOTING e

1 Supplemental Restraint System "Airbag"

2 Precautions

3 Pre-inspection

4 Electric Unit Location .

5 Troubleshooting Chart for Self-diagnosis System

6 Output Modes of Select Monitor

7 Control Unit I/O Signal

8 Troubleshooting for Engine Starting Failure

9 Troubleshooting Chart with Trouble Code

10 Troubleshooting Chart with Select Monitor

11 General Troubleshooting Table

2-7 [M1ool FUEL INJECTION SYSTEM

M MECHANISM AND FUNCTION

1 General

The Multi Point Fuel Injection (MPFI) system is a system

that supplies the optimum air-fuel mixture to the engine

for all the various operating conditions through the use

of the latest electronic technology.

With this system fuel, which is pressurized at a constant

pressure, is injected into the intake air passage of the

cylinder head The injection quantity of fuel is controlled

by an intermittent injection system where the

electro-magnetic injection valve (fuel injector) opens only for a

short period of time, depending on the quantity of air

required for one cycle of operation In actual operation,

the injection quantity is determined by the duration of

an electric pulse applied to the fuel injector and this

permits simple, yet highly precise metering of the fuel.Further, all the operating conditions of the engine areconverted into electric signals, and this results in addi-tional features of the system, such as large improvedadaptability, easier addition of compensating element,etc The MPFI system also has the following features :1) Reduced emission of harmful exhaust gases 2) Reduced in fuel consumption

3) Increased engine output

4) Superior acceleration and deceleration 5) Superior startability and warm-up performance incold weather since compensation is made for coolantand intake air temperature

1 Radiator main fan

2 Radiator sub fan

10 Fuel pump modulator

11 Roll over valve

12 Purge control solenoid valve

13 Canister

14 Throttle sensor

15 Auxiliary air control valve

16 By-pass air control solenoid valve

17 Throttle cable

18 Cruise control cable

19 Air flow sensor

20 Fuel filter

21 Fuel pump

22 Induction valve diaphragm

23 Induction control valve

31 Crank angle sensor 2

32 Water temperature sensor

33 Knock sensor 2 (LH)

34 Igniter

35 Ignition coil.

36 Cam angle sensor

37 Crank angle sensor 1

I 1 I 1 I

2-7 [M201 FUEL INJECTION SYSTEM

2 Air Line

1 GENERAL

Air which is drawn in and filtered by the air cleaner is

metered and sent to throttle body via the air intake boot

From the throttle body, the air is regulated by the

open-close operation of the throttle valve and is

deliv-ered to the collector chamber and the intake manifold It

is then distributed to the respective cylinders to mixwith fuel injected by the fuel injectors Thus, the air-fuelmixture is delivered into the cylinder Part of the airbranched at the upstream of the throttle body is sent tothe by-pass air control solenoid valve which regulatesengine idle speed

Air cleaner ~ ~{ Air flow sensor ~~J Throttle body f , ,~~ Collector chamber ~~J Intake manifold

By-pass air

con-trol solenoid J Fuel injectorvalve

Auxiliary aircontrol valve

2 AIR FLOW SENSOR

The MPFI system employs a hot-film type air flow

sensor

This air flow sensor converts the amount of intake air

into an electric signal by utilizing the heat transfer

phenomenon between the incoming air and heating

resistor located in the air intake

The features of this air flow sensor type are as follows:

1) High-altitude compensation is automatically made

-Hot film Hot wire

C2-161

Fig 2

In response to the depressing stroke of the throttle

pedal, the throttle body opens/closes its valve to

regu-late the air volume to be taken in the combustion

chamber

During idling, the throttle valve is almost fully closed

and the air flow through the throttle body is less than

that passing through the carburetor

More than half of the air necessary for idling is supplied

to the intake manifold via the by-pass air control

sole-noid valve

And the by-pass air control solenoid valve properly

controls the number of revolutions in idling, so it does

not need to be adjusted

4 THROTTLE SENSOR

This throttle sensor is provided with a potentiometer

The throttle sensor converts the opening of the throttle

valve into an electric signal, and sends it to the ECU

Using this signal, the ECU precisely controls the air-fuel

ratio during acceleration and deceleration as well as

idling

5 BY-PASS AIR CONTROL SOLENOID VALVE

The ECU controls the duty control valve in the by-pass

air control solenoid valve to bring the operating engine

speed as close to preset idle speed as possible

Solenoid

Connector

Air Inlet

Duty control valve

C2-163

Fig 3

Auxiliary air control valve consists of a bimetal, coilheater and rotary valve This valve supplies by-pass aironly when engine is cooled

Rotary valve

0 Valve fulcrum o II o ®'

Bimetal L Coil heater

C2-164Fig 4

7 COLLECTOR

The collector is the passage for distributing the intakeair into each cylinder It has the induction control valvebuilt in, and the air-induction is controlled by its opera-tion

2-7 (M3001 FUEL INJECTION SYSTEM

3 Fuel Line level by the pressure regulator on the way to the

injectors

1 GENERAL From the injectors, fuel is injected into the intake Fuel pressurized by the fuel pump built into the fuel tank ifold where it is mixed with intake air, and is then

man-is delivered to fuel injectors by way of the fuel pipe and delivered to the respective cylinders

fuel filter Fuel is regulated to the optimum pressure Fuel injection timing and the amount of fuel injected is

regulated by the ECU

F Fuel tank

Pressure regulator Cylinder

Delivery line Fuel cut valve

Fuel injector Return lineEvaporation line

Canister

Roll over valve

Fuel tank Jet pump Fuel pump

C2-017

Fig 5

The pressure regulator is divided into the fuel chamber

and the spring chamber by the diaphragm as illustrated

below Fuel is fed to the fuel chamber through the fuel

inlet connected with the injector A difference in

pres-sure between the fuel chamber and the spring chamber

connected with the intake manifold causes the

dia-phragm to be pushed down, and fuel is fed back to the

fuel tank through the return line

By returning fuel so as to balance the above pressure

difference and the spring force, the fuel pressure is kept

at a constant level 250.1 kPa (2.55 kg/cMZ, 36.3 psi)

against the intake manifold pressure

To intake Diaphragm

manifold

I

From Valve fuel injector

a

To fuel tank B2-284Fig 6

The MPFI system employs a gallery type (side-feedtype) fuel injector

The gallery type fuel injector is installed in the fuel pipe

to allow cooling of the injector by the fuel

The features of this type of fuel injector are as follows :1) High heat resistance

2) Low driving noise3) Easy to service4) Small sizeThe fuel injector injects fuel according to the valve opensignal received from the ECU

The nozzle is attached on the top of the fuel injector Theneedle valve is lifted by the solenoid coil through theplunger on arrival of the valve open signal

Since the injector opening, the lifted level of valve andthe regulator-controlled fuel pressure are kept constant,the amount of fuel to be injected can be controlled only

by the valve open signal from the ECU

Fig 7

2-7 [M4001 FUEL INJECTION SYSTEM

amount of air introduced in the cylinders

1 GENERAL This increase in the amount of air is generally referred toThe induction control system opens and closes the as the "high" charging efficiency

induction control valve to change the intake air flowrate

Pressure vibration in collector

00

en 0 o : Op 90

On low engine speed On high engine speed

C2-167

Fig 9

2 CONTROL FUNCTION

The induction control valve operates on the intake

manifold pressure transmitted to the diaphragm The

intake manifold pressure is controlled by opening/

closing the induction solenoid valve which is

deter-mined by the ECU according to the engine speed and

fuel injection quantity

o

ON i OFF (Close) ~~ (Open) ~~ Y1

2-7 [M500] FUEL INJECTION SYSTEM

5 Sensor and Switch

1 02 SENSOR

The OZ sensor is used to sense oxygen concentration in

the exhaust gas If the fuel ratio is leaner than the

stoichiometric ratio in the mixture (i e excessive

amount of air), the exhaust gas contains more oxygen

To the contrary, if the fuel ratio is richer than the

stoichiometric ratio, the exhaust gas contains hardly

any oxygen

Therefore, examination of the oxygen concentration in

exhaust gas makes it possible to show whether the

air/fuel ratio is leaner or richer than the stoichiometric

ratio

The Oz sensor has a zirconia tube (ceramic) which

generates voltage if there is a difference in oxygen

concentration between the inside and outside of the

tube Platinum is coated on the inside and outside of the

zirconia tube for the purpose of catalysis and electrode

provision The hexagon screw on the outside is

grounded to the exhaust pipe, and the inside is

con-nected to the ECU through the harness

A ceramic heater is employed to improve performance

at low temperature

B2-286Fig 11

When rich air-fuel mixture is burnt in the cylinder, the

oxygen in the exhaust gases reacts almost completely

through the catalytic action of the platinum coating on

the surface of the zirconia tube This results is a very

large difference in the oxygen concentration between

the inside and outside, and the electromotive force

generated is large

When a lean air-fuel mixture is burnt in the cylinder,

oxygen remains in the exhaust gases even after the

catalytic action, and this results in a small difference in

the oxygen concentration The electromotive force is

very small

The difference in oxygen concentration changes greatly

in the vicinity of the optimum air-fuel ratio, and hence

the change in the electromotive force is also large By

inputting this information into the MPFI control unit, the

air-fuel ratio of the supplied mixture can be determined

easily The Oz sensor does not generate much

electro-motive force when the temperature is low The teristics of the electromotive force stabilize at tempera-ture of approximately 300 to 400°C (572 to 752°F)

charac-Electromotive y Atmosphereforce

B2-287

Fig 12

2 WATER TEMPERATURE SENSOR

The water temperature sensor is located on the waterpipe which is made of aluminum alloy Its thermistorchanges resistance with respect to temperature A wa-ter temperature signal converted into resistance istransmitted to the ECU to control the amount of fuelinjection, ignition timing, purge control solenoid valve,etc

Y 2.5 20°C 168°F) 2.5 kn uc

m

1 -20 0 40 80 Temp °C (°F)(-4) (32) (104) (176)

20 60 (68) (140)

B2-288

Fig 13

The knock sensor is installed on the cylinder block, and

senses knocking signals from each cylinder

This knock sensor is a piezo-electric type which

con-verts knocking vibrations into electric signals

It consists of a piezo-electric element, weight, and case

If knocking occurs in the engine, the weight in the case

moves causing the piezo-electric element to generate a

voltage

' ' Connector _Weight

IIIResistor Housing

The crank angle sensor is a molded type which consists

of a magnet, pick-ups, coil, terminals, etc

Mold Terminal ASSY ° °

O-ring

\\\\ Ili Pickup Coil

~II

Case

Pickup Terminal , Molded tapeBobbin Insulator

B2-291

Fig 16

FunctionThe crank sprocket which is used with crank anglesensor 1, is provided with twelve protrusions Crankrotation causes these protrusions to cross crank anglesensor 1 so that magnetic fluxes in the coil change withthe change in air gap between the sensor pickup andthe sprocket The change in air gap induces an electro-motive force which is transmitted to ECU ECU detectsevery 30° of the crank angle

C2-1691

Fig 17

2-7 [M505] FUEL INJECTION SYSTEM

5 CRANK ANGLE SENSOR 2

The crank sprocket which is used for crank angle sensor

2, is provided with six protrusions As the crank

sprocket rotates as crank shaft the ECU detects that

each cylinder is divided into two grounds the

7 HOW TO DETECT EACH CYLINDER

The crank angle sensor 2 issues signals in the order of

3-pitches, 2-pitches, and 1-pitch, and the cam angle

sensor issues one signal for every two crankshaft

rota-6 CAM ANGLE SENSOR

Cam angle sensor is located on the left-hand camshaftsupport The back of LH cam sprocket is provided withone protrusion As the cam shaft sprocket rotates a halfcrank sprocket speed, cam angle sensor emits a signal

to the ECU whenever engine rotates two revolutions The ECU detects the compression top dead center ofeach cylinder with the crank angle sensor 2 signal which

is accompanied with the cam angle sensor signal

Cam angle sensor Air gap

Cam angle sensor

6 Control System

1 GENERAL

The ECU receives signals sent from various sensors and

switches to judge the engine operating condition and

emits output signals to provide the optimum control

and/or functioning of various systems

Major items governed by the ECU are as follow :

2 INPUT AND OUTPUT SIGNALS

Ignition system controlBy-pass air controlEGR controlCanister purge controlRadiator fan controlEngine torque controlAir conditioner cut controlSelf-diagnosis function

Air flow sensor Detects amount of intake air

Throttle sensor Detects throttle position

OZ sensor 1

OZ sensor 2 Detects the density of OZ in exhaust gases.

Crank angle sensor 1 Detects engine speed.

Crank angle sensor 2Cam angle sensor Detects the relative cylinder position.

Inpu s gnat i l Water temperature sensor Detects coolant temperature.

Knock sensor 1Knock sensor 2 Detects engine knocking for all cylinders Vehicle speed sensor Detects vehicle speed

Atmospheric pressure sensor Detects atmospheric pressure

Ignition switch Detects ignition switch operation

Starter switch Detects the condition of engine cranking Inhibitor switch Detects shift position

A/C switch Detects ON-OFF operation of A/C switch

Ignition signal Turn primary ignition current ON or OFF

Fuel pump relay Turn fuel pump relay ON or OFF

A/C control relay Turn A/C control relay ON or OFF

Output s gnai l Radiator fan control relay Turns radiator fan control relay ON or OFF

Induction control solenoid valve Controls Induction control valve

By-pass air control solenoid valve Adjusts amount of by-pass air through throttle valve.EGR solenoid valve Controls EGR valve

Purge control solenoid valve Controls canister purge control solenoid valve

2-7 [M6031 FUEL INJECTION SYSTEM

3 FUEL INJECTION CONTROL

ECU receives signals emitted from various sensors to

control the amount of fuel injected and the fuel injection

timing Sequential fuel injection control is utilized over

the entire engine operating range except during

stand-ing starts.

As for injection timing, the ECU controls the starting ofinjection with leading to the signal emitted from crankangle sensor 1

The starting of injection is changed between BTDC 50°(deg) and BTDC 10° (deg) under various conditions

I

I #5 Air intake timing

Intake valve I Open

The amount of fuel injected by the injector valve is

dependent upon the length of time it remains open The

optimum fuel injection timing is determined by

trans-mitting a signal to the injector from the ECU according

to varying engine operations Feedback control is also

accomplished by means of a learning control As a

result, the fuel injection control system is highly

respon-sive and accurate in design and structure

The sequential fuel injection system is designed so that

fuel is injected at a specific time to provide maximum air

intake efficiency for each cylinder In other words, fuel

injection is completed just before the intake valve

be-gins to open

Fuel injection timing is basically expressed as indicated

below :

(1) During engine starts :

Duration of fuel injection

= Duration of fuel injection during engine

starts

(2) During normal operation :

Basic duration of fuel injection x correction factor

+ voltage correction time

Basic duration of fuel injection The basic

length of time fuel is injected This is determined

by two factors the amount of intake air

de-tected by the air flow sensor and the engine

speed (rpm) monitored by the crank angle

sen-sor

Duration of fuel injection during engine starts

Determined according to the engine coolant

temperature detected by a signal emitted from

the water temperature sensor to improve

start-ing ability

Voltage correction time Compensates for the

fuel injector's time lag affected by the battery

voltage

2) Correction coefficients

Correction coefficients are used to correct the basic

duration of fuel injection so that the air-fuel ratio meets

the requirements of varying engine operations

These correction coefficients are classified as follows :

(1) Air-fuel ratio coefficient :

Allotted to provide the optimum air-fuel ratio in

rela-tion to engine speed and the basic amount of fuel

injected

rig It

(3) Water temperature increment coefficient:

Used to increase the amount of fuel injected inrelation to a signal emitted from the water tempera-ture sensor for easier starting of a cold engine Thelower the water temperature, the greater the incre-ment rate

Water temperature incrementA

dEd

(-4) (32) (68) (104) (140) (176) (°F)

Water temperature Water temperature increment characteristic

B2-300

Fig 24 (4) After-start increment coefficient : Increases the amount of fuel injected for a certain period of time immediately after the engine starts to stabilize engine operation

1-1g 22

(2) Start increment coefficient :

Increases the amount of fuel injected only when

cranking the engine, which improves starting ability.

0

t cE

4

At

t +At1t Elapse of time (after turning ignition switch OFF)

2-7 IM6o31 FUEL INJECTION SYSTEM

(5) Full increment coefficient:

Increases the amount of fuel injected by a signal

emitted from the throttle sensor in relation to a signal

emitted from the air flow sensor

(6) Acceleration increment coefficient :Compensates for time lags of air flow measurementand/or fuel injection during acceleration to providequick response

3) Air-fuel ratio feedback coefficient "alpha"

This feedback coefficient utilizes the OZ sensor's

elec-tromotive force (voltage) as a signal to be entered into

the ECU When low voltage is entered, the ECU judges

it as a lean mixture, and when high voltage is entered, it

is judged as a rich mixture In other words, when the

air-fuel ratio is richer than the theoretical air-fuel ratio,

t-nt°c

°tc :

U C

Variation in throttle valve position Acceleration increment characteristic

B2-303Fig 27

the amount of fuel injected is decreased When it isleaner, the amount of fuel injected is increased In thisway, the air-fuel ratio is compensated so that it comes

as close to the theoretical air-fuel ratio as possible onwhich the three-way catalyst acts most effectively (CO,

HC and NOx are also reduced when the air-fuel ratio isclose to theoretical air-fuel ratio )

ECU Combustion Exhaust gas

Fuel injector chamber Fuel increment signal Low oxygen density

4 Fuel injection I 1 High oxygen Fuel decrement signal Fuel injection increases density

1 Fuel injection decreases

I

sensor

O Lean air-fuel

1 Lean signal , ratio 1

Detec- Rich air-fuel Rich signal tion ratio

B2-304

Fig 28

In a conventional air-fuel feedback control system, the

basic amount of fuel injected (according to engine

speed and various loads) is stored in the memory After

the ECU receives a signal emitted from the OZ sensor,

the basic amount of fuel injected is corrected so that it is

close to the theoretical air-fuel ratio This means that the

greater the air-fuel ratio is corrected, the lesser the

control accuracy

Cam angle sensor

Crank angle sensor 1

Crank angle sensor 2

Air flow sensor

control system constantly memorizes the amount ofcorrection required in relation to the basic amount offuel to be injected (the basic amount of fuel injected isdetermined after several cycles of fuel injection), so thatthe correction affected by feedback control is mini-mized Thus, quick response and accurate control ofvariations in air-fuel ratio, sensors' and actuators' char-acteristics during operation, as well as in the air-fuelratio with the time of engine operation, are achieved Inaddition, accurate control contributes much to stability

of exhaust gases and driving performance

Inhibitor switch

2-7 [M604] FUEL INJECTION SYSTEM

4 IGNITION SYSTEM CONTROL This results in a reduced energy loss because no highThis ignition system is a direct ignition system which is tension cords are needed

composed of an ECU, six ignition coils, two knock One knock sensor is installed on the left cylinder block,sensors and other sensors Six ignition coils are directly and another on the right cylinder block, thus ensuringmounted to the spark plugs of the respective cylinders accurate digital engine knock control

-,Egl: - IgnitorWater tempe ratu re sensor

C2-052

Fig 29

from crank angle sensor 1, and sends the signal for crank angle sensor 2 and cam angle sensor,

igniter so as to spark the cylinder which is judged at

BTDC 100° 40°

i I

#t #6 I 700 i 10'-'130°~ I i i j #3 #2 #5

lin~'n'AIA~~AMAAWnnn

I I

I , I I Zone 1 I I I II

When engine speed is low, the ECU sends out the

ignition signal in synchronization with the 10 deg signal Zone 1 : Judge engine speed with angular velocity.Zone 2: Dowel-set with 70° signal

Zone 3: Ignition timing determined by ECU

Zone 4: Actual ignition timing

2-7 IMS051 FUEL INJECTION SYSTEM

5 BY-PASS AIR CONTROL (IDLE SPEED

CON-TROL)

The ECU controls the operation of by-pass air control

solenoid valve and auxiliary air control valve based on

the signal from crank angle sensor 1, throttle sensor,

vehicle speed sensor 2, water temperature sensor,

ignition switch, A/C switch and inhibitor switch, etc.When coolant temperature is cold, the amount of by-pass air is controlled by auxiliary air control valve andby-pass air control solenoid valve When coolant tem-perature is hot, it is controlled by only by-pass aircontrol solenoid valve

Ignition switch

Crank angle sensor 1

Crank angle sensor 2

Cam angle sensor

C2-178

Fig 31

The EGR system is composed of an EGR valve, EGR

solenoid valve, EGR vacuum controller, ECU, etc The

exhaust gas is recirculated when the EGR solenoid

valve opens to allow the intake manifold pressure to be

ECU controls the EGR solenoid valve based on thesignals sent from the water temperature sensor, OZsensors 1 and 2, crank angle sensor 1, etc

1 to control purge control solenoid valve Refer to C.2-1 Section 9.

2-7 [M608] FUEL INJECTION SYSTEM

8 RADIATOR FAN CONTROL

The radiator fan operation has four steps : off (OFF), low

(Lo), medium (MD), and high (HI) to reduce noise and

load

The operating condition of the radiator fan is mined by the combination of signals sent from the A/Cswitch, A/C trinary switch, vehicle speed sensor 2 andwater temperature sensor

deter-Vehicle speed Water temperature A/C trinary switch Operation

Unit : km/h (mph) Unit: °C (°F) Unit: kg/cm2 No 1 No 2 (RH) (LH)

0 : Signal ON X: signal OFF

9 ENGINE TORQUE CONTROL

In order to reduce gear shift shocks and protect

trans-mission gears, engine torque is controlled shifting up

under heavy loads or when the transmission is in the

manual mode

10 A/C SYSTEM CONTROL

The ECU controls ON/OFF of the air conditioning (A/C)system In addition, it controls the amount of electriccurrent sent to the NC compressor, thereby controllingthe quantity of refrigerant sent out by the compressor.When the A/C switch is set to ON when the coolanttemperature is high, the refrigerant delivery quantity isreduced to lower the coolant temperature, therebyprotecting the engine itself The same control system isadopted to smooth engine speed variations when theA/C switch is turned ON or OFF

7 Self-diagnosis System

1 GENERAL

The self-diagnosis system detects and indicates a fault

in various inputs and outputs of the complex electronic

control The warning light (CHECK ENGINE light) on the

instrument panel indicates occurrence of a fault or

trouble

Further, against such a failure or sensors as may disable

the drive, the fail-safe function is provided to ensure the

minimal driveability

2 FUNCTION OF SELF-DIAGNOSIS

The self-diagnosis function has four modes: U-check

mode, Read memory mode, D-check mode and Clear

memory mode Two terminals (Read memory and Test

mode) and light (CHECK ENGINE light) are used The

DIAG terminals are for mode selection and the light

monitors the type of problem

Relationship between modes and connectors

DIAG terminal

1 Test mode of MPFI

2 Read memory of MPFI

3 Clear memory of SRS

-5 Test mode of power steering

6 Read memory of power steering

7 Diagnosis of power steering

8 Diagnosis of passive belt

The U-check is a user-oriented mode in which only theMPFI components necessary for start-up and drive arediagnosed On occurrence of a fault, the warning light(CHECK ENGINE light) is lighted to indicate to the userthat the dealer's inspection is necessary The diagnosis

of other parts which do not give significant adverseeffect to start-up and drive are excluded from this mode

in order to avoid unnecessary uneasiness to be taken bythe user

Read memory modeThis mode is used by the dealer to read past problems(even when the vehicle's monitor light are off) It is mosteffective in detecting poor contact or loose connections

of connectors, harnesses, etc

D-check mode

This mode is used bythe dealerto checkthe entire MPFIsystem and detect faulty parts

Clear memory mode

This mode is used by the dealer to clear the troublecode from the memory after the affected part is re-paired

After checking on each mode, reinstall DIAG terminal

to wire harness with tape.

2-7 Inn7031 FUEL INJECTION SYSTEM

3 BASIC OPERATION OF SELF-DIAGNOSIS SYSTEM

Mode Read memory terminal Test mode terminal Condition CHECK ENGINE light

Ignition switch ON(Engine OFF) Trouble code(memory)

* When the engine operates at a speed greater than reached, the check engine light blinks

2,000 rpm for more than 40 seconds, the check ** When the engine operates at a speed greater thanengine light blinks However, when all check items 2,000 rpm for more than 40 seconds, a trouble codecheck out "O.K.',' even before the 40 seconds is is emitted

4 FAIL-SAFE FUNCTION

For the part which has been judged faulty in the

self-diagnosis, the ECU generates the associated pseudo

signal (only when convertible to electric signal) and

carries out the computational processing In this

fash-ion, the fail-safe function is performed

11 Crank angle sensor 1 No signal entered from crank angle sensor 1 morethan 3 seconds on start switch ON

-12 Starter switch Abnormal signal emitted from ignition switch Turns starter switch signal OFF

13 Cam angle sensor No signal entered from cam angle sensor, but sig-nal entered from crank angle sensor 1

14 Injector #1

15 Injector #2

16 Injector #3 Fuel injector inoperative.

17 Injector #4 (Abnormal signal emitted from monitor circuit ) _

18 Injector #5

19 Injector #6

21 Water temperature sen- Abnormal signal emitted from water temperature Adjusts water to a specific temperature.Maintains radiator fan "ON" to prevent

22 Knock sensor 1 (RH) Abnormal voltage produced in knock sensor mon- Sets regular fuel map and retards ignition timingitor circuit. by 5 °

23 Air flow sensor Abnormal voltage input entered from air flow sen- Controls the amount of fuel (injected) in relation tosor. engine speed and throttle sensor or position

24 Bypass air control sole- By-pass air control solenoid valve inoperated Prevents abnormal engine speed using "fuel cut"in relation engine speed, vehicle speed and noid valve (Abnormal signal produced in monitor circuit.) tle sensor position

throt-28 Knock sensor 2 (LH) Abnormal voltage produced in knock sensor mon- Sets regular fuel map and retards ignition timingitor circuit. by 5 °

29 Crank angle sensor 2 No signal entered from crank angle sensor 1, buttwo signals entered from cam angle sensor.

-31 Throttle sensor Abnormal voltage input entered from throttle sen- Sets throttle sensor's voltage output to fixedsor. value.

32 OZ sensor 1 (RH) Oz sensor 1 inoperative

-33 Vehicle speed sensor 2 Abnormal voltage input entered from vehiclespeed sensor 2. Sets vehicle speed signal to a fixed value

34 EGR solenoid valve EGR solenoid valve inoperative

-35 valvePurge control solenoid Purge control solenoid valve inoperative

-38 Engine torque control Wiring harness between ECU and TCU is in shortcircuit.

-41 A/F learning control Faulty learning control function

-45 Atmospheric pressuresensor Faulty atmospheric pressure sensor build in ECU

-51 Neutral switch Abnormal signal entered from inhibitor switch

-52 Parking switch Abnormal signal entered from parking switch

-55 EGR gas temperaturesensor (CAL.) ture sensor.Abnormal signal emitted from EGR gas tempera-

-56 EGR system (CAL.) EGR valve open/close stick, EGR hose disconnector exhaust pressure control valve damaged

-2-7 IC0001 FUEL INJECTION SYSTEM

1 EGR vacuum controller

2 EGR pipe cover

2 Air Intake Boot and Throttle Body

iu cm~ssion nose nn

11 Auxiliary air control valve

2-7 [C300] FUEL INJECTION SYSTEM

3 Air Cleaner

`\

1 Air flow sensor

2 Air cleaner upper cover

3 Air cleaner element

4 Air cleaner under cover

5 Clip

6 Bracket

7 Resonator CP

T TROUBLESHOOTING

1 Supplemental Restraint

Sys-tem "Airbag"

Airbag system wiring harness is routed near the MPFI

control unit (ECU), main relay and fuel pump relay.

a All Airbag system wiring harness and connectors

are colored yellow Do not use electrical test

equip-ment on these circuit

b Be careful not to damage Airbag system wiring

harness when servicing the MPFI control unit (ECU),

main relay and fuel pump relay

2 Precautions

1) Never connect the battery in reverse polarity

The MPFI control unit will be destroyed instantly

The fuel injector and other part will be damaged in

just a few minutes more

2) Do not disconnect the battery terminals while the

engine is running

e A large counter electromotive force will be generated

in the alternator, and this voltage may damage

elec-tronic parts such as ECU (MPFI control unit), etc

3) Before disconnecting the connectors of each sensor

and the ECU, be sure the turn off the ignition switch

Otherwise, the ECU may be damaged

4) The connectors to each sensor in the engine

com-partment and the harness connectors on the engine

side and body side are all designed to be waterproof

However, it is still necessary to take care not to allow

water to get into the connectors when washing the

vehicle, or when servicing the vehicle on a rainy day

5) Every MPFI-related part is a precision part Do not

drop them

6) Observe the following cautions when installing a

radio in MPFI equipped models

a The antenna must be kept as far apart as possible

from the control unit

(The ECU is located under the steering column,

inside of the instrument panel lower trim panel )

b The antenna feeder must be placed as far apart as

possible from the ECU and MPFI harness

c Carefully adjust the antenna for correct matching

d When mounting a large power type radio, pay

special attention to items a thru c above

Incorrect installation of the radio may affect the

operation of the ECU

7) Before disconnecting the fuel hose, disconnect the

fuel pump connector and crank the engine for more

than five seconds to release pressure in the fuel

sys-tem If engine starts during this operation, run it until it

stops

2) Check the condition of the main and other fuses, and harnesses and connectors Also check for proper grounding.

2 Caps and plugs

1) Check that the fuel cap is properly closed

2) Check that the oil filler cap is properly closed

3) Check that the oil level gauge is properly inserted

3 Intake manifold vacuum pressure

1) After warming up the engine, measure intake fold vacuum pressure while at idle

mani-Standard vacuum pressure:

Approx - 66.7 kPa (- 500 mmHg, - 19.69 in Hg)

Refer to C.2-2 [W5A0]

2) Unusual vacuum pressure occurs because of airleaks, fuel or engine problems In such a case, engineidles roughly

4 Fuel pressure 1) Release fuel pressure Refer to C.2-8 [W1A0].

2) Connect fuel pressure gauge between fuel filter andhose, and measure fuel pressure at idling

2-7 IT400) FUEL INJECTION SYSTEM

4 Electric Unit Location

1 SENSOR AND SOLENOID VALVE

30

solenoid valve solenoid valve

_ Crank angle I sensor 2

- I

I Crank angle

- ` sensor 1

C2-407

2-7 [T4021 FUEL INJECTION SYSTEM

2 CONTROL UNIT AND RELAY

Supplemental Restraint System "Airbag"

Airbag system wiring harness is routed near the MPFI

control unit (ECU), main relay and fuel pump relay.

C2-397

a All Airbag system wiring harness and connectors are colored yellow Do not use electrical test equip- ment on these circuit.

b Be careful not to damage Airbag system wiringharness when servicing the MPFI control unit (ECU),main relay and fuel pump relay

5 Troubleshooting Chart for Self-diagnosis System

A: BASIC TROUBLESHOOTING PROCEDURE

Trouble occursREAD MEMORY MODEEngine does not start Engine start

5 Troubleshooting for-Engine Starting Failure" I D-CHECK MODE[T6AOI *-

No trouble code

Inspection using Troubleshooting in ac- shooting Chart with Se-cordance with trouble lect Monitor [T8A0] orcode * inspection using GeneralTroubleshooting Table

** : When a trouble code is displayed in the read-memory mode, conduct troubleshooting measures which

-a Check the connector while it is connected unless specified otherwise

b Be sure to check again from the beginning in order to prevent secondary trouble caused by repair work

c When checking with the vacuum hose disconnected from the vacuum switch at E/G on, be sure to plug thehose

2-7 [T5B1] FUEL INJECTION SYSTEM

B : LIST OF TROUBLE CODES

1 TROUBLE CODES

Trouble code Item Diagnosis

11 Crank angle sensor 1 No signal from crank angle sensor 1 for more than 3 seconds after start switch ON

12 Starter switch Abnormal signal from ignition switch

13 Cam angle sensor No signal from cam angle sensor, but signal from crank angle sensor 1

14 Injector #1

15 Injector #2

16 Injector #3 Fuel injector inoperative.

17 Injector #4 (Abnormal signal from monitor circuit.)

18 Injector #5

19 Injector #6

21 Water temperaturesensor Abnormal signal from water temperature sensor

22 Knock sensor 1 (RH) Abnormal voltage in knock sensor monitor circuit

23 Air flow sensor Abnormal voltage from air flow sensor

24 By-pass air controlsolenoid valve By-pass air control solenoid valve inoperated.(Abnormal signal in monitor circuit )

28 Knock sensor 2 (LH) Abnormal voltage in knock sensor monitor circuit

29 Crank angle sensor 2 No signal from crank angle sensor 2, but two signals from crank angle sensor 1

31 Throttle sensor Abnormal voltage from throttle sensor

32 OZ sensor 1 (RH) OZ sensor 1 inoperative.

33 Vehicle speed sensor No signal from vehicle speed sensor 2

34 EGR solenoid valve EGR solenoid valve inoperative

35 valvePurge control solenoid Purge control solenoid valve inoperative

37 OZ sensor 2 (LH) OZ sensor 2 inoperative.

38 Engine torque control Wiring harness between ECU and TCU is in short circuit

41 A/F learning control Faulty learning control function

45 Atmospheric pressuresensor Faulty atmospheric pressure sensor inside ECU

51 Neutral switch Abnormal signal from inhibitor switch

52 Parking switch Abnormal signal from parking switch

55 EGR gas temperaturesensor (CAL.) Abnormal signal from EGR gas temperature sensor

56 EGR system (CAL.) EGR valve open/close stick, EGR hose disconnect or exhaust pressure control valve damaged

The CHECK ENGINE light flashes the code corresponding to the faulty part.

The long segment (1 2 sec on) indicates a ten", and the short segment (0 2 sec on) signifies one"

Fig 39

2-7 [T5C0] FUEL INJECTION SYSTEM

C: READ MEMORY MODE

Vehicle returned to dealer

Turn ignition switch OFF

Connect read memory terminal

Turn ignition switch ON (engine OFF)

Check if CHECK ENGINE light lights

up

NO ~ Inspect control unit power supply ~ and ground line, and CHECK ENGINEnlight line

YESTrouble code is indicated

Confirm trouble code

Disconnect read memory terminal

CHECK ENGINE light blinks.Disconnect read memory terminal

Self-diagnosis systems are O.K

Trouble is in a system other than aself-diagnosis system

Conduct D-check

D: D-CHECK MODE

Start engine

Warm up engine

Turn ignition switch OFF

Connect test mode terminal I

Turn ignition switch ON (engine off)

Check if CHECK ENGINE light turns on

YESDrive at speed greater than 11 km/h (7 mph) for at least

one minute

Warm up engine above 2,000 rpm.

Check if CHECK ENGINE light blinks YES

NONO

Check if CHECK ENGINE light indicates trouble code

YESConfirm trouble code

Make sequential checks of trouble codes

Turn ignition switch OFF

Disconnect test mode terminal

Self-diagnosis systems are O.K Trouble is in a systemother than a self-diagnosis system

2-7 [T5EOI FUEL INJECTION SYSTEM

E : CLEAR MEMORY MODE

Start engine.

Warm up engine

Turn ignition switch OFF

Connect test mode terminal

Connect read memory terminal

Turn ignition switch ON (engine off)

CHECK ENGINE light turns ON I

~

Depress accelerator pedal completely and then return it

to half-throttle position and hold it there for two

sec-onds Release accelerator pedal completely

Start engine

CHECK ENGINE light blinks to indicate vehicle

YESDrive at speed greater than 11 km/h (7 mph) for at least

one minutes

Warm up engine above 2,000 rpm

I Check if CHECK ENGINE light blinks

YES

NO I Check if CHECK ENGINE light indicates trouble code

YESTurn ignition switch OFF

Disconnect test mode terminal and read memory

termi-nal

Confirm trouble code

Make sequential checks of trouble codes

END I I After sequential checks, go to D-check mode again

6 Output Modes of Select Monitor

1 FUNCTION MODE

MODE Contents Abbre-viation measureUnit of Contents of display

F00 ROM-ID number YEAR - Model year of vehicle

F01 Battery voltage VB V Battery voltage supplied to ECU

F03 Vehicle speed signal VSP km/h Ve cle spee rom ve c e spee sensor 2.

F04 Engine speed signal EREV rpm Engine speed from crank angle sensor 1

F05 Water temperature signal TW degF

F06 Water temperature signal TW degC Coolant temperature from water temperature sensor.F07 Ignition timing ADVS deg Ignition timing calculated by ECU

F08 Air flow signal QA V Intake air flow converted to volts

F10 Throttle position signal THV V Throttle position converted to volts

F11 Injector pulse width TIM ms Ignition timing calculated by ECU

F12 By-pass air control ISC % "Duty" ratio on by-pass air control system

F13 OZ sensor 1 (RH) signal 02R V Voltage from OZ sensor 1 (RH)

F14 02 sensor 2 (LH) signal 02L V Voltage from OZ sensor 2 (LH)

F15 Oz Max (RH) 02Rmax V Maximum voltage from OZ sensor 1 (RH)

F16 02 Min (RH) 02Rmin V Minimum voltage from OZ sensor 1 (RH)

F17 02 Max (LH) 02Lmax V Maximum voltage from OZ sensor 2 (LH)

F18 Oz Min (LH) 021-min V Minimum voltage from OZ sensor 2 (LH)

F19 A/F correction coefficient 1 ALPHA1 % A/F ratio correction determined by ECU from OZ sensorF20 A/F correction coefficient 2 ALPHA2 % 1 and/or OZ sensor 2 signal(s)

F21 Knock sensor signal RTRD deg Correction determined by ECU from knock sensor 1and/or 2 signal(s).F22 Canister purge control CPCD % "Duty" ratio on purge control system

-FBO Trouble code DIAG - Trouble code in U- or D-check mode.

FB1 Trouble code DIAG - Trouble code in read memory mode

2-7 [T6021 FUEL INJECTION SYSTEM

9 49-states and Canada/California discrimination FC