1990 MAZDA 232 battery

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

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.
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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 F2
t OXYGEN SENSOR [BP TURBO]
I
CERAMlC HEATER
93GOF2-733
Because the temperature of the exhaust gas is inherently low in turbocharged engines, the BP Turbo model
uses a rapid heating ceramic heater to detect the air/fuel ratio,
PRESSURE REGULATOR CONTROL SYSTEM [BP TURBO]
PRESSURE
REGULATOR
I SOLENOID VALVE
(PRESSURE REGULATOR CONTROL)
FUEL
+ (FROM
DELIVERY PIPE1
II
FUEL INJ I
RELAY
(MAIN REU\Y)
I
II Ir
-__. _ - -’ VACUUM
CT0 DYNAMIC
Ill
CHAMBER)
BATTERY -
c
FUEL
(TO FUEL TANK)
nme*rn -.-a
To prevent percolation of the fuel during hot restart idle, vacuum to the pressure regulator k cut for 180
sec., and the fuel injection pressure is increased to slightly more than 284 kPa (2.90 kg/cm’, 41.2 psi).
Operating condition
l Coolant temperature: Above 90°C (194OF)
l Intake air temperature: Above 58OC (136OF)
g No-load condition
FZ-23

SELF-DIAGNOSIS FUNCTtON F2
Q3en
or short ci rculi - ON
26
OFF -
ON
34
OFF
ON
42
OFF
Caution
l If there is more than one failure present, the code numbers will be indicated in numerical or-
der, lowest number first.
l After repairing a failure, turn off the ignition switch, disconnect the negative battery cable,
and depress the brake pedai for at least five (5) seconds to erase the malfunction code(s) from
the ECU memory.
f2--27

F2 SELF-DIAGNOSlS FUNCTION
Troubleshooting
If a malfunction code number is shown on the SST (49 l-l01 8 9Ai, 49 B019 9AO), check for the cause
using the chart related to the code number shown, [Regarding code numbers except 05, 24, and 42, refer
to “Troubleshooting” in Workshop Manual [I 203-I O-89F (Europe) or 1204-f 0-89F (Australia)].
r C :ODE No. 05 (KNOCK CONTROL UNIT)-BP TUR80
;TEP
2
3 I INSPECTION
Check knock sensor and knock control unit
circuit for poor connectlon ACTtON
Yes Repalr or replace connector
Check knock control unit terminal voltage with
ignition switch ON
Check that voltage at ECU terminal 2J is
approx. 4V at idle
rs7 page F2-64 Yes Recheck ECU connector for poor
connection
4 If OK, replace ECU
4 If not OK, repair or replace connector
NO Repair wiring harness (R/Y) between
ECU terminal 2J and knock control unit
93GOF2-7:
Circuit Diagram
I
ECU
IGNITION
SWITCH
15A BATTERY
MAIN
RELAY
(FUEL 1N.J)
l W/L Y/i3 G/O W RIB R/L
YIL
jr- -- - - 1 BlLG
-
-
MCK CONTROL
I
. :
MAIN RELAY (FUEL INJ)
W/G BIW
C&=&A
KNOCK CONTROL UNIT
W/R EMLG RN Y/L
1
KNOCK SENSOR

SELF-DIAGNOSIS FUNCTION F2
:UDE No. 24 (FUEL PUMP RESISTOR/RELAY)-BP TURBO
STEP INSPECTION ACTtON
1 1 Disconnect connector from ECU and check if
1 battery voltage exists at connector terminal 1 I (L) Yes Check ECU terminal connector for poor
connection
with ignition switch ON
e If OK. replace ECU
c=> If not OK, repair or replace connector
NO Go to next step
2 In same condltlon as Step 1, check if battery
Yes Repair wiring harness (W/R)
voltage exists at resistor/relay connector terminai- I
wire (W/R)
NO Go to next step
3 Check if there is continuity between fuel pump
Yes Check for short or open circuit
in wiring
res!stor/relay terminals C (‘W/R) and D (L) from main relay (FUEL INJ relay) to
t resistor/relay
NO Replace resistor/relay
93GOF2-74 1 Circuit Diagram
IGNITION
SWITCH DIAGNOSIS
CONNECTOR
rl
F/P TERMINAL *
BATTERY
IGNlTlON
0fP
W/R
FUEL
PUMF
B
c W/R 7
FUEL PUMP
- RESISTOR/RELAY
\I
I/
ECU MAIN RELAY
Of1
W/G . LGrf Grw l v L/O R/Y LGlR YfL B/LG
RIB 1
I GIB J 1 1 [ WR LG ] Y , UW~LGIw/ * 1 W ] 810 WIG BfW
I
I I I
1 I I
I
&J,~&&&l&&c!zr5& &l~&cLa~~c!zch&&&&~
1~ IS 10 10 IM 1K II tC 1E 1C IA 2Y 2w 2u 2s 20 20 28.4 2K 21 2G 2E 2C 2A
IV 17 ?R IP 1N 1~ IJ III IF ro :8
rrrrrT?rrTT
BRff t BIG 1 R/W ! t/B 1 WIB 1 W/R
BIL UY O/B WN
CIRCUIT OPENING RELAY
FUEL PUMP FUEL PUMP RESlSTOR/RE~Y
v WIRBIP
B - LG
93GOF2.74
F2-29

F2 SELF-DIAGNOSlS FUNCTION
XIDE No. 1 42 (SOLENOID VALVE - WASTEGATE)-BP TURBO STEP
tNSPECTiON
ACTION
1
Disconnect connector from ECU and check if Yes Check ECU terminal connector for poor
battery voltage exists at connector terminal f H connection
(O/B) with Ignition switch ON
e If OK, replace ECU
4 tf not OK, repalr or replace connector
No Go to next step
2 in same condition as Step 1, check if battery Yes Repair wiring harness voltage extsts at solenoid valve connector
terminal-wire
NO Go to next step
3 Check if solenoid valve is OK
Yes Check for short or open circuit in wiring
.r3 page F2-46 from main relay (FUEL INJ relay) to
solenoid valve
NO Replace solenoid valve
Circuit Diagram
BA-iTERY
15A k
IGNITION SWITCH v /\: ./
WIG
B/w O/B
‘L a,
d
MAIN RELAY
(FUEL INJ)
WASTEGATE
SOtENOlD VALVE
ECU
WASTEGATE MAIN RELAY (FUEL INJ)
SOLENOfD VALVE
RIB 011 GIB WIG * LGIY L GM,
l v L/R
I
A WIG %fw
W/R
1u
10 1M 1K 71 B O/B
I I
i
B&Y B/L B;G UY Rh’ * I
I
IJB d/B WiB Wff W/R W/R B
F2-30