
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

TROUBLESHOOTING GUIDE F2
;TEP / t NSPECTION ACTION
4 i Check if throttle valve fully opens when depress- Yes Go to next step
rng accelerator fully
No Check if accelerator cabte is correctly
Installed *
-a If OK, check throttle body*
c=> If not OK, install accelerator cable
correctly*
5 Check if “00” fs dlsptayed on Self-Diagnosis
Yes Go to next step
Checker with ignition switch ON*
NO Malfunction Code No. displayed
SYSTEM SELECT: 1 Check for cause (Refer to specified
check sequence) *
“88” flashes
Check ECU terminal 1 F voltage
Voltage: Approx. f 2V
(Ignition switch ON) CT- page F2-60
i~sT SW: SELF TEST e If OK, replace ECU’
c3 ff not OK, check wiring between
ELECT SW: A ECU and Self-Diagnosis Checker
6 Check if continuity between throttle sensor termi- Yes Go to next step
nals IDt and E ts as shown’
7
Connect System Selector to diagnosis connector Yes Check if ignition timing advances when
and set Test Switch to “SELF TEST” and check accelerating
for correct ignition timing at idle after warm-up’
e If advances, go to next step
Ignitian timing: BTDC 10 f 1 D
=S If no advance, check ECU terminal
voltages
No Adjust
8
Check of ECU terminal voltages are OK Yes Go to next step
CT page F2-60
No Check for cause
9
Check for correct intake manrfold vacuum at idle Yes Go to next step
intake manifoId vacuum:
! More than 450 mmHg (17.7 inHg)
NO Check ior air leakage 07 intake air sys-
tem components
* Refer to 323 Workshop Manual [1203-IO-89F (Europe) or 1204-IO-89F (Australia)].
F2-37
![MAZDA 232 1990 Workshop Manual Suplement F2 TROUBLESHOUTING GUIDE
I 22 KNOCKtNG [8P TURBO] I
IESCW-
l Abnormal combustron accompanied by audible “pinging” noise rim
TROUBLESHOOTING HtNTS]
3 incorrect ignition timing (Too advanced) @ MAZDA 232 1990 Workshop Manual Suplement F2 TROUBLESHOUTING GUIDE
I 22 KNOCKtNG [8P TURBO] I
IESCW-
l Abnormal combustron accompanied by audible “pinging” noise rim
TROUBLESHOOTING HtNTS]
3 incorrect ignition timing (Too advanced) @](/manual-img/28/57056/w960_57056-156.png)
F2 TROUBLESHOUTING GUIDE
I 22 KNOCKtNG [8P TURBO] I
IESCW-
l Abnormal combustron accompanied by audible “pinging” noise rim
TROUBLESHOOTING HtNTS]
3 incorrect ignition timing (Too advanced) @ Low octan fuel used
2
Knock control system malfunction @ Air/Fuel mixture lean
3 Carbon deposits in cylinder l Fuel injection amount not correct
3 Overheating l Fuel line pressure decreases while accelerating
TEP INSPECTION ACTlON
1
Connect System Selector to diagnosis connector Yes Go to next step
and set Test Switch to “SELF TEST” and check
for correct ignition timing at idle after warm-up’
ignition timing: BTDC 10 f lo
No Adjust
2 Check if “00” is displayed on Self-Diagnosis Yes Go to next step
Checker with igmtlon switch UN*
No Matf unction Code No. displayed
Check for cause (Refer to specified
check sequence) *
“88” flashes
Check ECU terminal 1 F voltage
Vottage: Approx. 12V
(Ignition switch ON) 0 page FZ-60
4 If OK, replace ECU
W: SELF TEST
4 If not OK, check wiring between
ECU and Self-Diagnosis Checker
3 Check for correct fuel line pressure at idle* Yes Check if fuel Iine pressure decreases
when accelerating quickly
Fuel line pressure:
265-314 kPa (2.7-3.2 kg/cm2, 38-46 psi)
(vacuum hose to pressure regulator dis-
connected) 4 If decreases, check for clogging
between fuel pump and pressure
regulator
e If no decrease, go to next step
No tow pressure Check
fuel line pressure while pinching
fuel return hose
3 If fuel line pressure quickly in-
creases, check pressure
regulator*
4 If fuel line pressure gradually in-
creases, check for clogging be-
tween fuel pump and
pressure
regutator
If not clogged, check fuel pump
maximum pressure*
- -
.-
Refer to 323 Workshop Manual [1203-IO-89f (Europe} or t204-IO-89f (Australia)]. F2-40

F2 FUEL SYSTEM
93GOF2-775
1 93GOF2-78(
93GOF2-78:
1
93GOF2-78;
-
93GOF2-783
FUEL PUMP RESISTOR/RELAY
System Operation
I. Remove the rear seat cushion.
2,
Measure the voltage at the fuel pump connector terminal
A {G/O).
Voltage
r Crankinq Approx. 12V
I
I- Others t ACKXOX. I OV i
3. If not within specification, perform the following inspection,
and repair or replace if necessary.
l Fuel pump resistor/relay resistance. (Refer to below.)
l ECU II terminal voltage. (Refer to page F2-60.)
l Wiring harness and connector.
inspection
1.. Disconnect the connector.
2. Ground the fuel pump resister relay terminal D.
3. Apply 12V to terminal C and check for continuity between
terminals A and B.
Terminal C
12 applied
ov Continutty between A and B
NO
Yes
4. Measure the resistance between terminals E and F.
Resistance : 0.62-0.66Q [at 20% (68OF)l
INJECTOR
Volume Test
1. Remove the injectors with the delivery pipe.
2. Affix the injectors to the delivery pipe with wire.
Caution
l Affix the injectors firmly to the delivery pipe so that
no movement of the-injectors is possible.
Warning
l Be extremely careful when working with fuel.
Always work away from sparks or open flames.
3. Connect the SST to the battery and injector.
4. Check the injection volume with a graduated container.
Injection volume:
BP SUHC....44-47 cc (2.68-2.87 cu in)/15 sec.
BP Turbo
. ...87-105 cc (5.31 -6.41 cu in)/15 sec.
Caution
l When using the SST, make sure of the SST num-
ber and use correct one.
5. If nut correct, replace the injector(s).

CONTROL SYSTEM F2
CONTROLSYSTEM
PREPARATION
SST
49 HOt8 9A3
Self-dragnosls
checker
Engrne signal
IT-iOFlllO~ 49 GO18 904
Sheet System selector
I 93GUF2-786
For inspection of ECU
93GOF2-787
93GOF2-801
TERMNALS 1
--I”- -
03UOFX
ENGINE CONTROL UNIT (ECU)
Inspection
1. Disconnect the ECU connectors.
2. Connect the SSTs (Engine Signal Monitor and Adapt-
er) to the ECU as shown.
3. Place
the SST (Sheet) 011 the Engine Signal Monitor.
4. Measure the voltage at each terminal.
(Refer to pages FZ-60 to F2-67.)
5. If any ECU terminal voltage is incorrect, check the related
input or output devices and wiring. If no problem is found,
reptace the ECU. (Refer to above.)
Caution l
Never apply voltage to SST terminals A and B.
F2-59

CONTROL SYSTEM F2
Incorrect voltage Possible cause
Always OV
l ROOM 10A fuse burned l Open circuit in wiring from ROOM 10A fuse to ECU termrnal IA
Always OV
I l Main relay maifunctlon l Open or short crrcu~t in wirrng from main relay to ECU termrnal 1 B
Always OV (Srarrer turns)
l Open or short circuit in wiring from ignition switch to ECU terminal 1C
Always UV
l Main relay (FUEL INJ relay} malfunctron l Open circuit in wiring from main relay to diagnosis connector terminal + B l Open or short circuit in wiring from dragnosls connector terminal MEN to
ECU terminal 1D
Always approx. 12V
I . Poor connection at ECU connector
l ECU matfunction
Always approx. 5V
l ECU malfunction
-
I -
Always below No disptay on Self- . Main relay (FUEL INJ retay) malfunction (Refer to page F3-142)
2.5V Diagnosis Checker l Open circuit in wiring from main relay to diagnosis connector termjnal + B
“88” displayed and
l Open or short circuit in wiring from diagnosis connector terminal FEN to
buzzer sounds con- ECU terminal 1 F
tinuously
Always approx. 12V
l Poor connection at ECU connector l ECU malfunction
Always OV
l Short circuit in wiring from igniter to ECU terminal tG
Atways OV or approx. 12V
l Refer to Code No.42 Troubleshooting (Refer to page F2-30)
Always approx. 12V
l Fuel pump resistor/relay malfunction
Always OV
l Open or short circuit in wiring from ECU terminal 1 I to resistor/retay
Always below
A/C does not operate
l AJC relay malfunction
23 l Open circuit in wiring from ignition switch to NC relay l Open circuit in wiring from A/C relay to ECU terminal IJ
A/C switch OFF but
l Short circuit in wiring from A/C relay to ECU terminal IJ
AIC operates
l ECU matfunction
Always approx. t2V
Always below 1 .OV
l Poor connection at ECU connector l ECU malfunction
l Short circurt in wiring from diagnosis connector terminal TEN to ECU termi-
nal 1K
Always approx. 12V
l Open circutt in wiring from diagnosis connector terminal TEN to ECU termi-
nal lK
l Open c~rcud in wiring from diagnosis connector terminal GND to ground
Always above 1 .OV
I
l Open circuit in wiring from ECU terminal 1 M to ground
F2-61

CONTROL SYSTEM F2
Incorrect voltage
Always below 1 .OV Possible cause
l Throttle sensor misadjustment l Short circuit in wiring from throttle sensor to ECU terminal IN l ECU malfunction
Always approx. f 2V
Atways below 1 .OV (Stopfights OK)
Always below 1 .OV
l Throttle sensor misadjustment l Open circuit in wiring from throttle sensor to ECU terminal IN l Open ctrcuit in wiring from throttle sensor to ECU terminal 20
l Open crrcurt in wiring from stoplight switch to ECU terminal 10
l P/S pressure switch malfunction l Short circuit in wirrng from P/S pressure switch to ECU termrnai 1 P
l ECU malfunction
Always approx. 12V
Atways below 2.5V (Btower fan OK) . P/S pressure switch malfunction
l Open circuit in wiring from P/S pressure switch to ECU terminal I P l Open circuit in wiring from P/S pressure switch to ground
l A/C switch malfunction l Short circuit in wiring from A/C switch to ECU terminal 1 Q l Poor connection at ECU connector l ECU malfunction
Always approx. 12V (Blower fan OK)
l ’ A/C switch malfunction l Open c~rcurt in wiring from NC switch to ECU terminal 1Q l ken circuit H-I winnu from A/C switch to blower control switch
Always below 1.W
l Open or short circuit in wiring from fan relay to ECU terminal IR
(Electrkal cooling fan UK} l ECU malfunctron
Always below 1 .OV (Blower fan OK)
l Short crrcutt in wiring from blower control swrfch to ECU terminal IS l Poor connection at ECU connector l ECU malfunction
Always approx. 12V (Blower fan OK)
Always below Illumination lamp
1.w ON when rear
window defroster
switch ON 1
l Open circurt in wrring from blower control switch to ECU terminat IS
I
l Open or short circuit rn wiring from rear window defroster switch to ECU
terminal 1 T
ftlumination lamp
never ON
l Open circuit in wiring from ignition switch to rear window defroster switch
l Rear window defroster switch malfunction I
Always below 1 .OV (Headlights OK)
l Open or short circurt in wiring from headlight relay to ECU termtnal 1 U
Always below 1 .OV
Always approx. l2V
l Neutral switch malfunction l Clutch switch malfunction l Short circuit in wiring from ECU terminal IV to neutral or clutch switch
l Neutral switch maifunctton l Clutch switch malfunction l Open circuit in wiring from ECU terminal IV to neutral or clutch swttch
l Poor connection at ECU connector
93GOFZ789
F2-63