1992 MAZDA PROTEGE ECU

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

CONTROL SYSTEM F
VB: Battery voltage
Incorrect voltage Possible cause
Always OV l ROOM 10A fuse burned l Open circuit in wiring from ROOM 10A 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
Always OV (Starter turns)
l Open or short circuit in wiring from or inhibitor switch (ATX) to ECU termi-
nal 1C
Always OV
Always Ve
Always 4.5~5.5U
l Main relay (FUEL INJ 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
25v
Always Va 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
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 connection at ECU connector l ECU malfunction
Always OV
l Short circuit in wiring from igniter to ECU terminal 1G
Always below 1 .OV (Headlights OK)
l Open or short circuit in wiring from headlight relay to ECU terminal 1H
(Refer to page F-171)
Always OV
Always VB
Always OV Illumination lamp
ON when rear
window defroster
switch ON
Illumination lamp
never ON
Approx. 5V (California)
Always OV (Canada)
l Short circuit in wiring from diagnosis connector terminal TEN to ECU termi-
nal II
l Open circuit in wiring from diagnosis connector terminal TEN to ECU termi-
nal II
l Open circuit in wiring from diagnosis connector terminal GND to ground
l Open or short circuit in wiring from rear window defroster switch to ECU
terminal 1 J
l Open circuit in wiring from ignition switch to rear window defroster switch l Rear window defroster switch malfunction (Refer to page T-21)
l Open circuit in wiring from ECU terminal 1K to ground
l Short circuit in wiring from ECU terminal 1K to main relay (FUEL INJ relay)
23UOFX-14: 2
f-1 59

CONTROL SYSTEM
Incorrect voltage Possible cause
VB: Battery voltage
Always below
2.W A/C does not operate l A/C relay malfunction (Refer to page U-55) l Open circuit in wiring from ignition switch to A/C relay l Open circuit in wiring from A/C relay to ECU terminal IL
AIC switch OFF but
l Short circuit in wiring from A/C relay to ECU terminal 1L
A/C ooerates l ECU malfunction
Always Va
l Poor connection at ECU connector l ECU malfunction
Always OV
l Vehicle speed sensor malfunction (Refer to page K-143)
l Short circuit in wiring from vehicle speed sensor to ECU terminal 1M
l Vehicle speed sensor malfunction (Refer to page K-143) l Open circuit in wiring from vehicle speed sensor to ECU terminal 1M
Always OV
l P/S pressure switch malfunction (Refer to page F-173) l Short circuit in wiring from P/S pressure switch to ECU terminal 1P l ECU malfunction
Always Va
Always below 2.5V (Blower fan OK)
Always Ve (Blower fan OK)
l P/S pressure switch malfunction (Refer to page F-173) l Open circuit in wiring from P/S pressure switch to ECU terminal 1P l Open circuit in wiring from P/S pressure switch to ground
l A/C switch malfunction (Refer to page U-55) l Short circuit in wiring from A/C switch to ECU terminal IQ l Poor connection at ECU connector l ECU malfunction
l A/C switch malfunction (Refer to page U-55) l Open circuit in wiring from A/C switch to ECU terminal 1Q l Open circuit in wiring from A/C switch to blower control switch
Always OV (Blower fan OK)
Always VB (Blower fan OK)
Always below 1 .OV (Stoplight OK)
l Short circuit in wiring from blower control switch to ECU terminal 1s l Poor connection at ECU connector
l ECU malfunction
l Open circuit in wiring from blower control switch to ECU terminal 1s
l Open circuit in wiring from stoplight switch to ECU terminal 10
Always OV
Always Ve
l Inhibitor switch malfunction (Refer to page K-141) l Short circuit in wiring from inhibitor switch to ECU terminal 1R
l Inhibitor switch malfunction (Refer to page K-141) l Open circuit in wiring from inhibitor switch to ECU terminal 1R
Always OV
l Cruise switch malfunction (Refer to page T-21) l Short circuit in wiring from cruise switch to ECU terminal 1s
l Cruise switch malfunction (Refer to page T-21) l Open circuit in wiring from cruise switch to ECU terminal IS
Always OV
l Throttle sensor misadjustment (Refer to page F-169) l Short circuit in wiring from throttle sensor to ECU terminal 1T
l ECU malfunction
Always Va
I
l Throttle sensor misadjustment (Refer to page F-169) l Open circuit in wiring from throttle sensor to ECU terminal 1T
-
I - - -
Always approx. OV or approx. 2V l Refer to Code No.02 Troubleshooting (Refer to page F-86)
F-l 61

CONTROL SYSTEM F
Incorrect voltage Possible cause ____-__l_ll____-
Always approx. OV or approx. 5V l Refer to Code No.08 Troubleshooting (Refer to page F-90)
IV after warm-up
Jlways approx. IV after warm-up
l Refer to Code No.15 Troubleshooting (Refer to page F-98)
l Refer to Code No.1 7 Troubleshooting (Refer to page F-100)
qlways OV
Electrical cooling fan OK)
l Open or short circuit in wiring from fan relay to ECU terminal 20 l ECU malfunction
I Always approx. OV or approx. 5V l Refer to Code No.09 Troubleshooting (Refer to page F-92)
Always constant
C\lways above 1V
4lways constant . Open circuit in wiring from ECU terminal 2F to throttle sensor
l Open circuit in wiring from ECU terminal 21 to throttle sensor l Open circuit in wiring from ECU terminal 3D to throttle sensor
l Throttle sensor misadjustment
l ATF termosensor malfunction (Refer to page K-142) l Open or short circuit in wiring from ATF termosensor to ECU terminal 2G
c\lways OV
l Hold switch malfunction (Refer to page K-140) l Short circuit in wiring from hold switch to ECU terminal 2H
4lways Va
l Hold switch malfunction (Refer to page K-140) l Open circuit in wiring from hold switch to ECU terminal 2H
Always OV
l Short circuit in wiring from ECU terminal 21 to throttle sensor airflow meter,
or water thermosensor
l Poor connection at ECU connector
Below 4.W or above 5.W
Always approx. OV or approx. I..% l ECU malfunction
l ECU malfunction
l Refer to Code No.03 Troubleshooting (Refer to page F-88)
Always approx. OV or approx. 5V 9 Refer to Code No.10 Troubleshooting (Refer to page F-94)
I
- - VB:
Battery voltage
Always constant
l Pulse genrotor malfunction (Refer to page K-142) l Open or short circuit in wiring from pulse generator to ECU terminal 2M
Above OV
l Poor connection at ground terminal l Open circuit in wiring from ECU terminal 2N to ground
F-l 63

CONTROL SYSTEM F
Incorrect voltage
Above OV
Always OV
Always VB
Always Va
Always OV
Always Ve
Always OV
Always VB
Always approx. OV or VB -
-
-
Always OV or Ve -
-
-
Always OV or Vs -
-
- Possible cause
VB: Battery voltage
l Poor connect at ground terminal l Open circuit in wiring from ECU to ground
l Inhibitor switch malfunction (Refer to page K-141) l Short circuit in wirina from inhibitor switch to ECU terminal 3E
l Inhibitor switch malfunction (Refer to page K-141)
. Open circuit in wiring from inhibitor switch to ECU terminal 3E
l Short circuit in wiring from DRL relay to ECU terminal IL l Short circuit in wiring from DRL relay to DRL unit
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)
l Inhibitor switch malfunction (Refer to page K-141) l Short circuit in wiring from inhibitor switch to ECU terminal 3G
l Inhibitor switch malfunction (Refer to page K-141) l Short circuit in wiring from inhibitor switch to ECU terminal 3G
l Inhibitor switch malfunction (Refer to page K-141) l Short circuit in wiring from inhibitor switch to ECU terminal 3H
l Inhibitor switch malfunction (Refer to page K-141) l Open circuit in wiring from inhibitor switch to ECU terminal 2H
l Refer to Code No.41 Troubleshooting (Refer to page F-103) -
-
-
l Refer to Code No.25 Troubleshooting (Refer to page F-102) -
-
-
l Refer to Code No.34 Troubleshooting (Refer to page F-103) -
-
F-l 65

CONTROL SYSTEM
Ve: Betterv voltaae
Incorrect voltage Possible csuse
Always OV l Main relay (FUEL INJ relay) malfunction (Refer to page F-172) l Open or short circuit in wiring from injector to ECU terminal 3U or 3V
Always Ve
l ECU malfunction
Always OV
Always Ve
l 1-2 shift solenoid valve malfunction (Refer to page K-143) l Short circuit in wiring from solenoid valve to ECU terminal 3W
I
l l-2 shift solenoid valve malfunction (Refer to page K-143) l Ooen circuit in wiring from solenoid valve to ECU terminal 3W
Always OV
l 2-3 shift solenoid valve malfunction (Refer to page K-143) l Short circuit in wirino from solenoid valve to ECU terminal 3X
Always VB
Always OV
l 2-3 shift solenoid valve malfunction (Refer to page K-143) l Open circuit in wiring from solenoid valve to ECU terminal 3X
l 3-4 shift solenoid valve malfunction (Refer to page K-143) l Short circuit in wiring from solenoid valve to ECU terminal 3Y
Always
VB l 3-4 shift solenoid valve malfunction (Refer to page K-143) l Open circuit in wiring from solenoid valve to ECU terminal 3Y
Always OV
l Lockup solenoid valve malfunction (Refer to page K-143) l Short circuit in wiring from solenoid valve to ECU terminal 32
Always Ve
l Lockup solenoid valve malfunction (Refer to page K-143) l Open circuit in wiring from solenoid valve to ECU terminal 32
23UOFX-1 E i0
F-l 67

IGNITION SYSTEM G
IGNITION SYSTEM
PREPARATION
SST
49 NO18 001
Adapter Harness
CIRCUIT DIAGRAM
ECU
T
IGNITION SWITCH
,
I
DISTRIBUTOR
7
1 ZL BATTERY
IGNITER
03UOGX-03t
G-15

G IGNITION SYSTEM
TROUBLESHOOTING
iTEP
INSPECTION
ACTION
1
Check if MIL illuminates when engine is running Yes Check for malfunction code number
and perform troubleshooting (TEN ter-
minal grounded) c7 Section F
No Go to next step
2 Drsconnect high-tension lead from distributor and
Yes
check for strong blue spark while cranking en-
l Check distributor cap and rotor v page G-22
gine * Check high-tension lead
KP page G-19 c7 page G-17
+ Ignition system normal
No
Go to next step
3 Check if resistance of ignition coil is OK
Yes
Go to next step ~7
page G-19
Specification (at 20°C [66”9):
Primary coil winding: 0.81-0.99Q No
Replace ignition coil
Secondary coil winding: IO-16 kQ
-i
Check if resistance of high-tension leads is OK Yes Go to next step
D= page G-17
Specification: 16 kQ per 1 m (3.28 ft)
No Replace high-tension lead
5 Check if igniter is OK
m- page G-23 Yes
Replace ECU
No
Replace igniter
03UOGX-03
G-16