1992 MAZDA PROTEGE fuel

F FUEL
23UOFX-12:
0-6V
23UOFX- 131
to the terminal 2U or 2V (MTX), 3U or 3V (ATX)
hat the green and red lamps flash alternately.
nd No,3.....ECU terminal 2U (MTX)
3U (ATX)
. . . ..ECU terminal 2V (MTX)
3V (ATX)
6. Increase the engine speed to 4,000 rpm and then suddenly
release the throttle.
7. Verify that the red indicator lamp illuminates while the en-
gine speed is above approx.
1,900 rpm on deceleration.
t aced maximum rpm over 3 sec.
8. Increase the engine speed and verify that the maximum rpm
does not exceed specification.
.
.
. ..“.*..1”*“.-.“.....*......*...
Approx. 7,300 rpm
. . ..I......m....“.....*........m Approx. 6,300 rpm
F-l 44

DECHOKE CONTROL SYSTEM t-
DECHOKE CONTROL SYSTEM
DESCRIPTION
To facilitate starting the engine when the spark plugs become fouled, such as when the engine is flooded,
fuel injection is cut if the throttle valve is held wide open while cranking and the engine coolant temperature
is O°C (32OF) or below. This allows the spark oluas to drv and purges excess fuel from the cylinders.
f-- ECU _
. IGNITION SWITCH (START)
l ENGINE SPEED BELOW 500 rpm ’
l THROTTLE VALVE FULLY OPEN
l ENGINE COOLANT TEMPERATURE ;
BELOW
0% (32°F) I FUEL CUT
OBUOFX-19
I / / ‘ I
SYSTEM OPERATION
1.
2. Check if the engine coolant temperature is below O°C
(32OF).
If the engine coolant temperature is above O°C (32OF), dis-
connect the water thermosensor connector and connect an
approx. 10 kB resistor to the connector.
03UOFX.198 3. Turn the ignition switch to START and verify that the injec-
OBUOFX-19! 3
tor operating sound is heard.
4. Depress the accelerator pedal fully and turn the ignition
switch START. Verify that no injector operating sound is
heard.
F-l 45

F CONTROL SYSTEM
STRUCTURAL VIEW
23UOFX-1:
1. Engine control unit (ECU) 8. Solenoid valve (Pressure regulator control)
- .--
Removal / Installation . . . . . . . . . . . . . . . . page F-149
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page F-149
2. Circuit opening relay
Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . page F-l 29
Inspection ,...,........................... page F-l 29
3. Clutch switch (MTX)
inspection . . . . . . . . . . . . . . . . . . . . . . . . . page F-l 72
4. Airflow meter (With intake air thermosensor)
Inspection .,..........,...,............... page F-l 68
5. ISC valve
Inspection .,*,........,.,.........,....... page F-116
Removal / Installation . . . . . . . . ,.... page F-l 09
G-Throttle sensor
Inspection . . . . . . . . . . . . , . . . . . . page F- 169
Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . page F-l 09
7. Solenoid valve (VICS) [DOHC]
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page F-l 18 Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9. Water thermosensor
Inspection. . . . . . . .
Removal I Installation ....I..........
10. Solenoid valve(Purge control)
Inspection ,............ ,..................
11, Main relay (FUEL INJ relay)
Inspection. ..,............................
12. Neutral switch (MTX)
Inspection ,.,,,,....I.l,,.........I.......
Replacement . . . . . . .
13. Oxygen sensor
Inspection,. . . .
Replacement . , . . . .
14. P/S pressure switch
Inspection . . ..__.._._._........
Replacement . , . . . . . . . . . . . . . page t-135
page F-l 68
page F--l 68
page F-l 40
page F-172
page F-l 73
page F-173
page F-171
page F-172
--
page F-173
page F-173
F-l 48

CONTROL SYSTEM
Terminal voltage (MTX)
VB: Battery voltage
wminal Input Output Connection to Test condition Correct voltage Remark
1A - - Battery Constant VB For backup
1B 0 Main relay OFF OV
(FUEL INJ relay) Ignition switch ._-
ON VB
1c 0 Ignition switch While cranking Approx. 10V
(START) -
Ignition switch ON ov
10 0 Self-Diagnosis Test switch at “SELF-TEST” With Self-
Checker Lamp illuminated for 3 sec. after ignition 4.5--5.5v Diagnosis Check-
(Monitor lamp) switch OFF+ON er and System
Lamp not illuminated after 3 sec. VEI Selector
Test switch at “02 MONITOR” at idle
Monitor lamp illuminated 4.5-5.5v
Test switch at
“02 MONITOR” at idle
Monitor lamp not illuminated Va
1E 0 Malfunction indica- Lamp illuminated for 3 sec. after ignition
Below 2.5V With System
tor lamp (MIL) switch OFF-ON Selector test
Lamp not illuminated after 3 sec.
VB switch at
“SELF-TEST”
Lamp illuminated Below 2.5V
Lamp not illuminated VR
1F
0 Self-Diagnosis Buzzer sounded for 3 sec. after ignition
Below 2.5V
l With Self-
Checker switch OFF+ON Diagnosis
(Code Number)
Buzzer not sounded after 3 sec. VE - Checker and
Buzzer sounded Below 2.5V System Selector
l With System
Buzzer not sounded
VB Selector test
switch at
“SELF-TEST”
1G 0 Igniter Ignition switch ON ov
-
Idle Approx. 0.2V
1H - - - - - -
_-
II - - - - - -
1J
0 AIC relay Ignition switch ON
VB
A/C switch ON at idle Below 2.5V
A/C switch OFF at idle VB
-
1K 0 Diagnosis
connector
(TEN terminal) System Selector test switch at
“02 MONITOR”
System Selector test switch at
“SELF-TEST” VB
ov Ignition switch
ON
1L 0 DRL relay
(Canada) Parking brake pulled with ignition switch
Ve
l DRL.: Daytime
ON (DRL OFF) Running Lights
Idle (DRL ON) Below 2.5V
V’
F-l 50

CONTROL SYSTEM F
VB: Battery voltage
incorrect voltage POBSible cause
Alwvs OV’ l ROOM IOA fuse burned l Open circuit in wiring from ROOM IOA fuse to ECU terminal 1A
Always OV
l Main relay malfunction (Refer to page F-171) l Open or short circuit in wiring from main relay to ECU terminal 1B
I
Always OV (Starter turns) l Open or short circuit in wiring from starter interlock switch (USA), ignition
switch (CANADA), to ECU terminal 1C
I
Always OV
Always Vs
Always approx. 5V
l Main relay (FUEL IWJ relay) malfunction (Refer to page F-171) l Open circuit in wiring from main relay to diagnosis connector terminal +B l Open or short circuit in wiring from diagnosis connector terminal MEN to
ECU terminal 1D
l Poor connection at ECU connector l ECU malfunction
l ECU malfunction
Always below
23 MIL always ON
MIL never ON
l Short circuit in wiring from combination meter to ECU terminal 1E l ECU malfunction
l Open circuit in wiring from combination meter to ECU terminal 1E
I
Always Ve l Poor connection at ECU connector l ECU malfunction
Always below
2.5V
Always
VB
No display on Self- * Main relay (FUEL INJ relay) malfunction (Refer to page F-171)
Diagnosis Checker l Open circuit in wiring from main relay to diagnosis connector terminal +B
“88” displayed and
l Open or short circuit in wiring from diagnosis connector terminal FEN to
buzzer sounds con- ECU terminal 1F
tinuously
l Poor connectron at ECU connector l ECU malfunction
Always OV
l Short circuit in wiring from igniter to ECU terminal 1G
I -
I -
I
I -
I -
I
Always below
2.5V
Always VB AIC does not operate l A/C relay malfunction (Refer to page U-55) l Open circurt in wiring from ignition switch to A/C relay l Open circuit in wiring from A/C relay to ECU terminal 1J
A/C switch OFF but
l Short circuit in wiring from A/C relay to ECU terminal IJ
AIC operates l ECU malfunction
l Poor connection at ECU connector l ECU malfunction
Always below l.OV
l Short circuit in wiring from diagnosis connector terminal TEN to ECU termi-
nal 1K
Always Vs
l Open circuit in wiring from diagnosis connector terminal TEN to ECU termi-
nal 1K
l Open circuit in wiring from diaonosis connector terminal GND to ground
Always below
2.W
Always Va DRL ON when ignition
l Short circuit in wiring from DRL relay to ECU terminal IL
switch ON l Short circuit in wiring from DRL relay to DRL unit
DRL never ON
l Open circuit in wiring from DRL relay to ignition switch
l Parking brake switch always ON l DRL unit malfunction (Refer to page T-33)
23UOFX- 134
F-l 51

CONTROL SYSTEM
Ve: Battery voltage
Incorrect voltage
I Possible cause
4bove OV
l Poor contact at ground terminal l Open circuit in wiring from ECU to ground
Always approx. OV or approx. 2V
l Refer to Code No.02 Troubleshooting (Refer to page F-86) -
r\lways approx. OV or approx. 1.W - l Refer to Code No.03 Troubleshooting (Refer to page F-88)
Approx. 4.5-5.5V (California)
Always OV (Canada)
l Open circuit in wiring from ECU terminal 2H to ground
l Short circuit in wiring from ECU terminal 2l-i to main relay (FUEL INJ relay) - -
Approx. 4.5--55V l ECU malfunction
Always OV
l Short circuit in wiring from ECU terminal 2K to throttle sensor, or airflow
meter
Below 4.5V or above 5.5V
l Poor connection at ECU connector l ECU malfunction
1
l ECU malfunction
Always OV
l Throttle sensor malfunction (Refer to page F-169) l Short circuit in wiring from ECU terminal 2L to throttle sensor l Poor connectron at ECU connector l ECU malfunction
Always 4.5--5.W
Always constant
l Throttle sensor misadjustment (Refer to page F-169) l Open circuit in wiring from ECU terminal 2L to throttle sensor l Open circuit in wiring from ECU terminal 2L to ECU terminal 2D
l Open circuit in wiring from ECU terminal 2M to throttle sensor
l Open circuit in wiring from ECU terminal 2K to throttle sensor l Open circuit in wiring from ECU terminal 20 to throttle sensor
Always above 1V 1
l Throttle sensor misadjustment
OV after warm-up
Always approx. 1V after warm-up (
l Refer to Code No.15 Troubleshooting (Refer to page F-98)
I * Refer to Code No.1 7 Troubleshooting (Refer to page F-100)
Always OV or 4.5-5.5V
Always OV or 4.5~-5.W
I l
Refer to Code No.08 Troubleshooting (Refer to page F-90) l
Refer to Code No.10 Troubleshootrng (Refer to page F-94)
Always OV or 4.5-5.W l
Refer to Code No.09 Troubleshooting (Refer to page F-92) -
23UOFX-131
F-l 55

CONTROL SYSTEM
Incorrect voltage
Always OV or VB
Always OV or VS
VB: BBttWy voltage
Possible cause
l Refer to Code No.41 Troubleshooting (Refer to page F-103)
l Refer to Code No.25 Troubleshooting (Refer to page F-102)
Always OV
l Main relay (FUEL INJ relay) malfunction (Refer to page F-172)
6 Open or short circuit in wiring from injector to ECU terminal 2U or 2V
Always Ve
l ECU malfunction
Always OV or
VB
Always OV or Va
l Refer to Code No.34 Troubleshooting (Refer to page F-103)
l Refer to Code No.26 Troubleshooting (Refer to page F-102)
23UOFX-140
F-t 57

F CONTROL SYSTEM
Terminal voltage (ATX)
VB: Battery voltage
erminal Input Output
Connection to Test condition Correct voltage Remark
IA - -
Battery Constant --- Va For backup
16 0 Main relay
lgnrtion switch OFF ov
(FUEL INJ relay) -
ON Vs
IC 0 Ignition switch While cranking Approx. 1 OV
(START) -
Ignition switch ON
ov
_
ID 0 Self-Diagnosis Test switch at “SELF-TEST” With Self-
Checker Lamp illuminated for 3 sec. after ignition 4.5-5.5v Diagnosis Check-
(Monitor lamp) switch OFF-ON er and System
Lamp not illuminated after 3 sec.
VB Selector
Test switch at “02 MONITOR” at idle
Monitor lamp illuminated 4.5-5.5v
Test switch at
“02 MONITOR” at idle
Monitor lamp not illuminated VB
1E 0 Malfunction indica- Lamp illuminated for 3 sec. after ignition
Below 2.5V With System
tor lamp (MIL) switch OFF+ON Selector test
Lamp not illuminated after 3
sec. VS switch at
“SELF-TEST”
Lamp illuminated Below 2.5V
Lamp not illuminated VR
IF 0 Self-Diagnosis Buzzer sounded for 3 sec. after ignition
Below 2.5V
l With Self-
Checker switch OFF+ON Diagnosis
(Code Number)
Buzzer not sounded after 3 sec.
VB Checker and
Buzzer sounded Below 2.5V System Selector
l With System
Buzzer not sounded
VB Selector test
switch at
“SELF-TEST”
IG 0 Igniter Ignition switch ON ov
-
Idle Approx. 0.2V
1H 0 Headlight switch Headlrghts ON VB
-
Headlights OFF Below 1 .OV
II
0 Diagnosis System Selector test switch at Ignition switch
connector
“02 MONITOR” VE
ON
(TEN terminal)
System Selector test switch at
“SELF-TEST” ov
1J 0 Rear window
defroster switch Rear window defroster switch OFF
Rear window defroster switch ON ov
VB
Ignition switch
- ON
1K 0 Ground (California) Constant ov
Main relay Ignition switch ON VB -
I
3 J
IJ- J-1
u- Fl
IJ -‘--l. r
3~ lawlau13SI3Q13013M]3K131 13Gl3EI3C (3A 20]2M;2KI21 (2Gl2E12C)2A ltJ~LS~lo)l01~~1~ II IIG~IE( 1CIlA
32 13x I3v 13~13~l3~13N13~13~13~13~I 3~ 138 ~P)~N)L?L~~J(~H(~F~~D~z!B iv ~IT~IR~IP IN~IL 1 J IIHIIFI ID~IS
F-l 58