1990 MAZDA 232 ECU

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

TRUUBLESHOOT1NG GUIDE
TROUBLESHOOTING GUIDE [BP TURBO]
RELAT1ONSt-W CHART
,
i OUTPUT DEVICE
INPUT DEVfCE
KNOCK SENSOR
1
I
-
I-
3 DIAGNOSIS CONNECTOR
(TEN TERMfNAL)
IGNITION SWITCH
(START POSITION)
0 0 0 Cl
EIL SIGNAL * ’
0 0
0 0
P/S PRESSURE SWITCH
0
1
0 0 A/C SWITCH
0 0 0 0 NEUTRAt AND CLUTCH
SWfTCHES 0 0
0
STOPLIGHT SWITCH
0
0
0 0 0 ATMOSPHERIC PRESSURE
SENSOR (IN ECU) 0
0
THROTTLE SENSOR 0 0 0 0 0
0 INTAKE AfR THERMOSENSOR 0
AlRFLOW METER 0 0
I------ i
0 OXYGEN SENSOR
WATER THERMOSENSOR 0
0 0
O G-SIGNAL
DISTRIBUTOR
I---- Ne-SIGNAL I-L 0 0 L-
0
0
L.- 0 0
L 0 0
93GOF2-i45
*I E/L SIGNAL: Slower fan control switch Second position or higher, cooSing fan operating? headlights ON, or rear wtn-
dow defroster switch ON

TROUBLESHUOT1NG GUIDE F2
;TEP
14
15
16 Change fuel and check if condjtjon improves INSPECTION
Check if resistance of rgnrtm
coil IS OK’
Resistance (at 20°C [SS*Fj):
Primary coil winding _....-.. Cl.81 -0.99Q
Secondary coil winding.,.. IO-16 kQ ACTION
Yes Go to next step
PRIMARY COIL
WINDING SECONDARY COIL
WIND tNG
Check fur correct engine compressron”
Yes Go to next step
Engine compression:
785 kPa (8.0 kg/cm2, 1 I4 psi)-300’ rpm L 1
No Check engine condition *
l Worn p&ton, piston rings or cylinder
wall
l Defective cylinder head gasket l Distorted cylinder head l Improper valve seating
l Valve sticking in guide
Yes Change fuel to another brand
No
I I Try known good ECU and check if con-
dition imDroves
* Refer to 323 Workshop Manual [ 1203-lo-89F (Europe) or 1204-l O-89F (Australia)l.
93GOF2-74 6
F2-35

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

TROUBLESl-lOOTING GUIDE F2
;TEP 1 INSPECT1ON
ACTION
13 Check if resistance of ignition coil 1s OK*
Yes Go to next step
Resistance (at 20°C iSS*FJ):
Primary coil winding . . . . . . . .
0.81~-0.99Q
Secondary coil winding,,.. 1 O--16 kR
PRIMARY COIL
WINDING SECONDARY COIL
WlNDlNG
NO Replace
14 Check for correct engine compression”
Yes Gc to next step
1 Engine compression (Minimum):
785 kPa (8.0 kg/cm , It4 psi)-300 ipm
NO Check engine condition” l Worn piston, piston rings or cylinder
wall
l Defective cylinder head gasket l Distorted cylinder head l Improper valve seating
*Valve sthing in guide
15 Change fuel and check if acceleration improves
Yes Change fuel to another brand
NO
Go to next step
16 Check if NC cut-off control system is OK’
Yes Go to next step
No Repair or replace
17
I Try known good ECU and check if condition
improves
* Refer to 323 Workshop Manual [1203-IO-89F (Europe) or i204-IO-89F (Australia)].
93GOF2-747
F2-39

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

I
F2
fNSPECTlON ACTION
I Check if cootrng system IS OK’
YES Go to next step
No Repair or reptace
l Thermostat l
l Electric cooling fan * l Radiator*
5 Try known good ECU and check if condltlon Yes Replace ECU * rnproves
NO Change fuel to another brand or use
higher octane fuel
l Refer to 323 Workshop Manual [1203-l O-89F (Europe) or It 204-I O-89F (Australia)]. %%‘3OF2-748 -
F2-4 I