ECU MAZDA 232 1990 Suplement User Guide

-- -
“-
I t-
SQLENOlD VALVE AEAR WINOOW
(PRESSURE IQNITION HEADLIG t IT
DEFFIOSTER
REGULATOR SWITCH SWITCH
SWITCH
CONTROL)
lNJECTOR ELECTRICAL
MAIN RELAY , FAN
AX SWITCH
r DliiGNOSlS BLOWER Ivc
CONNECTOR SWITCH RELAY
ECU
AIRFLOW METER
Tt
WATE!
THERMOSENSOR
CLUTCH [/ t
-I
’ NEUTRAL
SWITCH SWITCH 4X4 CONTROL UNIT
1
FbEL
PUMP
TRANSFER PUMP TRANSFER
PUMP SWlTCtJ

SUPPLEMENTAL SERVICE INFORMATION, FUEL SYSTEM Fl
SUPPLEMENTAL SERVICE INFORMATION
The following points in this section are changed in comparison with Mazda 323 Workshop Manuals
(I 203-I U-89F, 1204-I O-89F, I2061 O-89F).
fuel tank
l Removal I Inspection I Installation
4x4 control unit (Fuel pump control unit)
l Inspection procedure added
l Replacement procedure added
Transfer pump switch
l Inspection procedure added
l Replacement procedure added
Transfer pump
l Inspection procedure added
l Replacement procedure added
Exhaust system components
l Removai I Inspection I installation 93GOF? -706
FUELSYSTEM
PRECAUTION
Fuel Pressure Release and Sewicing Fuel System
Fuel in the fuel system remains under high pressure when the
engine is not running.
a) Before disconnecting any fuel line, release the fuel
pres-
sure from the fuel system to reduce the possibility of injury
or fire.
1. Start the engine.
2. Push the rear seat cushion buttons and remove the
cushion.
3. Disconnect the fuel pump connector.
4. After the engine stalls, turn off the ignition switch.
5. Reconnect the fuel pump connector and install the rear
seat cushion.
b) Use a rag as protection from fuel spray when disconnect-
ing the hoses.
Plug the hoses after removal.
c> When inspecting the fuel system, use a suitable fuel pres-
sure gauge.
Caution
l Install hose clamps to secure tile fuel pressure
gauge to the fuel filter and the fuel main hose to pre-
vent fuel leakage.
Priming Fuel System
After releasing the fuel pressure for repairs or inspection, the
system must be primed to avoid excessive cranking when first
starting the engine. Follow the
steps below.
I. Connect the diagnosis connector terminals F/P and GND
with a jumper wire.
2. Turn the ignition switch ON for approx. IO sec. and check
for fuel leaks.
3. Turn the ignition switch OFF and remove the jumper wire.
Fl-9

F2
FUEL AND EMISSION
CONTROL SYSTEMS
(WITH CATALYTIC CONVERTER)
.
INDEX ..*.........**.*.........*..........*...... F2- 2
OUTLINE ...................................... F2- 4
OUTLINE OF CONSTRUCTION.. .... F2- 4
SYSTEM DIAGRAM ...................... F2- 5
VACUUM HOSE ROUTING
DIAGRAM [BP TURBO] ............... F2- 7
WIRING DlAGRAM.. ..................... FZ- 8
ECU REtATlONSHIP DIAGRAM
[BP TURBO] .............................. F2-10
SPEClFtCATlONS. ........................ F2-11
TURBOCHARGER CONTROL
[BP TURBO] ................................ F2-I 2
OUTLINE .................................... F2-I 2
SYSTEM DIAGRAM ................. .; ... F2-12
WASTEGATE CONTROL ...............
F2-13
FUEL,SYSTEM
.............................. F2-15
OUTLINE
.................................... F2-15
CONSTRUCTlON ......................... F2-15
FUEL VAPOR VALVE ................... F2-16
FUEL PUMP CONTROL SYSTEM.. . F2-16
FUEL PUMP RESISTOR/RELAY ...... F2-18
TRANSFER PUMP CONTROL. ....... F2-I 8
CONTROL SYSTEM ....................... F2-20
STRUCTURAL VIEW.. ................... F2-20
OVERBOOST WARN!NG BUZZER
[BP TURBO] .............................. F2-21
TURBOCI-IARGE INDICATOR
[BP TURBO] .............................. F2-21
KNOCK CONTROL SYSTEM
[BP TURBO] .............................. F2-22
OXYGEN SENSOR [BP TURBO]. .... F2-23
PRESSURE REGULATOR CONTROL
SYSTEM [BP TURBO] ................. F2-23
A/C CUT-OFF SYSTEM (ATX) .........
F2-24 SUPPLEMENTAL SERVICE
INFORMATION ............................. F2-25
SELF-DIAGNOSIS FUNCTION .......... F2-26
OUTLINE
.................................... F2-26
MALFUNCTION CODE NUMBERS . . F2-26
TROUBLESHOOTtNG GUIDE
[BP TURBO1
................................ F2-31
RELATlONSHlP CHART ................ F2-31
SYMPTOM TRUUBLESH0OTlNG .... F2-32
tNTAKE AIR SYSTEM ..................... F2-43
COMPONENTS ............................ F2-43
TURBOCHARGERCONTROL
SYSTEM ...................................... F2-45
PREPARATION ............................ F2-45
SYSTEM OPERATION ................... F2-45
WASTEGATE ............................... F2-45
WASTEGATE SOLENOID VALVE.. .. F2-46
TURBOCHARGER ........................ F2-46
AIR BYPASS VALVE ..................... F2-48
INTERCOOLER ............................ F2-49
FUEL SYSTEM .............................. F2-50
PREPARATION ............................ F2-50
PRECAUTION ............................. F2-50
FUEL TANK
................................ F2-51
TRANSFER PUMP CONTROL
SYSTEM ................................... F2-52
FUEL PUMP CONTROL UNIT ........ F2-53
TRANSFER PUMP SWITCH ........... F2-54
TRANSFER PUMP.. ...................... F2-54
FUEL PUMP RESISTOR/RELAY ...... F2-56
INJECTOR
.................................. F2-56
EXHAUST SYSTEM
COMPONENTS .................................................... ;ff;
CONTROL SYSTEM ....................... F2-59
PREPARATION
............................ F2-59
ENGINE CONTROL UNIT (ECU) ..... F2-59
OXYGEN SENSOR ....................... F2-68
KNOCK SENSOR ......................... F2-69
93GOF2.701

F2 OUTLINE
ECU RELATIONSHIP DlAGRAM [BP TURBO]
INPUT DEVICE KNOCK SENSOR
KNOCK
i( CONTROL
DlSTRlBUTOR ,-, UNIT
NC SWITCH
--k/L SWITCHS
{REAR WINDOW DEFROSTER SWITCH.
HEADLIGHT SWITCH, BLOWER SWITCH,
ELECTRICAL FAN SWITCH)
BATTERY A
THRO77LE
SENSOR
NEUTRAL/ IDENTIFICATION
CLUTCH SWITCH
DIAGNOSIS
CONNECTOR
(TEN TERMINAL) INTAKE AIR
THERMOSENSOR
OUTPUT DEVICE
CIRCUIT
OPENING
SOLENOID VALVE
(PRESSURE REGULATOR
WASTEGATE
SOLENOID VALVE
RESISTOR/RELAY
SOLENOID VALVE
(PURGE CONTROL)
93GOFZ-71
F2-10

TURBOCHARGER CONTROL [BP TURBO] F2
WASTEGATE CONTROL
The engine control unit controls the wastegate solenoid valve to give higher boost to the engine in the higher
rpm range, increasing engine torque
and power.
System
Diagram
I
t
1 ECU
i i
AIRFLOW METER ACTUATOR
WASTEGATE
WASTEGATE
SOLENOID VALVE
r ACTUATOR
WASTEGATE SOLENOID VALVE
: OFF (VALVE CLOSED)
ACTUATOR
BOOST
PRESSURE
WASTEGATE SULENOlD VALVE
: ON (VALVE OPEN) Operation
Engine speed below 5,300 rpm
The
wastegate solenoid valve is OFF. Boost pressure is ap-
plied directly to the actuator and the wastegate opens when
the boost pressure exceeds 49 kPa (0.5 kg/cm , 7.1
psi).
Engine speed above 5,300 rpm
The wastegate
solenoid valve is UN. Some boost pressure is
bypassed to the intake manifold, limiting the opening of the
wastegate to increase boost pressure and
improve engine per-
formance.
F2-13

F2 FUEL SYSTEM
FUEL VAPOR VALVE
FUEL VAPOR VALVE
93GOF2-722
The fuel vapor valve is installed in the fuel tank to allow fuel vapors within the tank to escape to the charcoal
canister.
The fuel vapor valve contains a shut-off valve to prevent raw fuel from escaping during hard cornering
01
at other times when there is significant fuel slosh.
FUEL PUMP CONTROL SYSTEM [BP TURBO]
Outline
l The fuel pump control system supplies electric power to the fuel pump at ail times while the engine is
running. The fuel pump can thus operate even though the fuel pump switch in the airflow meter OFF.
rhe fuel pump switch may open (switch OFF) on deceleration due to back-flow of air from the turbocharger.]
l To improve fuel pump longevity, the fuel pump is controlled by the engine control unit (ECU). (Refer to
next page.)
MAIN RELAY (FUEL 1NJ RELAY)
I I FUEL PUMP
RESISTOR/RELAY ECU
I
ON
P CIRCUIT OPENING
I--
DIAGNOSIS
CONNECTOR
TERMINAL F/P CPU
F2-16

FUEL SYSTEM F2
Two-stage WeI pump operation
Engine running (Except heavy load or cranking)
The ECU 1 I circuit is ON, opening the contact plate in the fuel pump resistor/relay. Current from the circuit
opening relay to the fuel pump flows through the resistor in the fuel pump resistor/relay, and the voltage
to the fuel pump is reduced to approx. WV, causing the fuel pump to operate at a reduced speed to im-
move fuel pump longevity.
MAIN RELAY
Engine under heavy load or cranking
The ECU 1 I circuit is OFF and the contact plate in the fuel pump resistor/relay is closed. Unreduced battery
current flows to the fuel pump through the contact plate, causing the fuel pump speed and output to be
increased to meet the demands of the engine.
I
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93GW2-725
FZ-17

F2 FUEL SYSTEM
93GOF2-726
FUEL PUMP RESISTOR/RELAY [BP TURBO]
The fuel pump resistorlretay supplies battery voltage to the
fuel pump when the ECU 11 circuit is OFF, and approx. 1 OV
when the ECU 11 circuit is ON. It is mounted on the firewall.
TRANSFER PUMP CONTROL
Outline
The fuel tank is buitt with separate right and left sections to accommodate the. installation of the propeller
shaft. As fuel is puited from the right side of the tank, the transfer pump pumps the fuel from the left to the
right (fuel pumb) side to balance the fuel level.
FUEL IN LEFT TANK
I
FUEL PUMP CONTROL. UNIT
/ TRANSFER PUMP
TRANSFER PUMP SWITCH: OFF
NO FUEL IN LEFT
TANK
FUEL PUMP CONTROL UNIT / TRiNSFER PUMP
TRANSFER PUMP SWITCH: UN
93GOF2-727
Operation 1. Whenever the ignition switch is ON and fuel is in the left (transfer pump)
side of the fuel tank the fuel pump switch is open, the transfer pump circuit in the fuel pump control unit is
closed, and the transfer pump
operates.
2. When the fuel in the left side of the tank drips betow a specified point, the fuel pump switch is grounded
and the transfer pump stops operation.
3. To prevent the transfer pump from
being turned ON and OFF repeatedly, possibly shorting the life of the
pump, when the vehicle is driven on a rough
road and the fuel level is low, there is a ten-second delay
circuit in the control unit to delay the turning ON and OFF the pump.
f2--I 8

CONTROL SYSTEM
WE~DOST WARNlNG BUZZER [BP TURBO]
To improve engine reliability, the overboost warning buzzer installed in the instrument cluster sounds during
overboost conditions as detected by engine
speed and intake air amount caiculations within the ECU. The
driver is thus warned to reduce engine
speed.
DETECTtON
OVERBOOST
BUZZER
TURBOCHARGE INDICATOR [BP TURBO]
When the turbocharger boost pressure calcul’ated by intake air amount and engine speed reaches the predeter-
mined level and the transaxle is in gear, the turbocharge indicator illuminates to inform the driver of turbocharge
operation.
1
AIRFLOW METER
DISTRI BUTUR
rd” i
4 NEUTRAUCLUTCH
SWITCH ECU
* CALCULATION
-, OF
BOOST
PRESSURE
TURBOCHARGE
INDICATOR

F2 CONTROL SYSTEM
KNOCK CONTROL SYSTEM [BP TURBO]
This svstem retards the ignition timina when enaine knocking occurs because of usage of low octane fuel, etc.
1NTAKE
MANIFO
KNOCK SENSOR
(INSTALLED BETWEEN No.2 AND
No.3 CYLINDER)
IGNITER
KNOCK iX?NTROL
UNIT
Operation
When the engine vibrates, the knock sensor generates a slight voltage signal that is the sent to the knock
control unit. The knock control unit determines whether the signal is a knocking signal. If it is a knocking
signal, the ignition spark is retarded according to the intensity of the knock to a maximum of 4O.
Inhibition of spark retardation
In order to improve drivability and fuel economy, the ECU inhibits the above spark retardation when the
‘engine load Ls light, the coolant temperature is below O°C (32OF), the engine is cranking during engine test
conditions.
Note
l The knock ~ensur and knock control unit cannot be inspected individually.
When a matfunction code number 05 is indicated, replace the knock controt unit or sensor
only after inspecting the related wiring and connectors.
F2-22