ecu wiring MAZDA PROTEGE 1992 Owner's Guide

SELF-DIAGNOSIS FUNCTION
:ODE No. 09 (WATER THERMOSENSOR)
iTEP INSPECTION ACTION
1 Check water thermosensor circuit for poor con-
Yes Repair or replace connector
nection
3 Check if resistance of water thermosensor is OK Yes Go to next step
Coolant temp. Resistance (kg)
No Replace water thermosensor
-20% ( -4OF) 14.6-17.8
2o”c ( 68OF) 2.21-2.69
80% (176OF) 0.29-0.35
4 Check if same Code No. is present following Yes Go to next step
after-repair procedure
w page F-104 No
Water thermosensor and circuit OK
5 Check if ECU terminals voltages are OK
Yes Replace ECU w page F-149
MTX...2D and 20
ATX...2E and 3D
w page F-152 No Check for short circuit in wiring from
water thermosensor to ECU
-- ._-..__
23Uu~X-ut
4
-’
F-92

F SELF-DIAGNOSIS FUNCTION
:ODE No.
10 (INTAKE AIR THERMOSENSOR - IN AIRFLOW METER)
TEP INSPECTION
ACTION
1 Check intake air thermosensor circuit for poor
Yes Repair or replace connector
connection
No Go to next step
2 Check if Code No.08 is also present
Yes Check for open circuit in wiring from
airflow meter terminal wires (BILG) and
(B/BR) to ground
Go to next step
3 Check wire harness between intake air
thermosensor and ECU for continuity
4 Check if resistance of airflow meter between
Yes Go to next step
terminals C (BIBR) and G (R/B) is OK
r
Temperature ~ No
Resistance (kg) Replace airflow meter
-20% 13.6-18.4
20% 2.21-2.69
60% 0.493-0.667
5 Check if same Code No. is present following
Yes Go to next step
after-repair procedure
CT page F-104 No
Intake air thermosensor and circuit OK
6 Check if ECU terminals voltages are OK Yes Replace ECU IT- page F-149
MTX...2D and 2P
ATX... 2K and 3D
CT page F-152 No Check for short circuit in wiring from
intake air thermosensor to ECU
23UOFX-06 -
F-94

F SELF-DIAGNOSIS FUNCTION
:ODE No. 12 (THROTTLE SENSOR - ATX)
iTEP INSPECTION ACTION
1 Check throttle sensor circuit for poor connection Yes Repair or replace connector
No Go to next step
2 Check wire harness between throttle sensor and Yes Go to next step
ECU for continuity
Throttle sensor ECU - No Repair or replace
A (LG/R) 2K (MTX) 21 (ATX)
B U-4 2M (MTX) 2F (ATX)
D (BIBR)
20 (MTX) 3D (ATX)
3 Check if resistances between terminals B (LGIW)
Adjust or replace throttle sensor w page F-169
4
r.%$ if$CU terminal 2M (MTX) 2F (ATX) volt- Yes Replace ECU w page F-149
w page F-154 NO
Check for short circuit in wiring from
throttle sensor to ECU
23UOFX-06
.-’

F SELF-DIAGNOSIS FUNCTION
CODE No.
STEP
1
Repiace ECU -- -.. - 14 (ATMOSPHERIC PRESSURE SENSOR - IN ECU)
ACTION
m page F-149 -.
23UOFX-069
:ODE No. 15 (OXYGEN SENSOR - INACTIVATION)
Note
l If Code Nos. 15 and 17 are both present, first perform the checking procedure for Code No.17
iTEP
INSPECTION ACTION
1 Check oxygen sensor circuit for poor connection
YeSi Repair or replace connector
No Go to next step
2 Check if oxygen sensor output voltage is OK Yes
Go to next step
rr5+ page F-171
No Replace oxygen sensor
3 Check wire harness between oxygen sensor and Yes Go to next step
ECU terminal 2N (MTX) 2C (ATX) for continuity
NO Repair or replace
4 Check if ECU terminal 2N (MTX) 2C (ATX) volt-
Yes Go to next step
age is OK
w page F-154
No
Check for short circuit in wiring from
oxygen sensor to ECU
5 Check if sensitivity of oxygen sensor is OK
Yes Replace ECU
w page F-149
CT page F-171
No Try known good oxygen sensor and
check if condition improves w page F-172
23UOFX-07C
F-98

SELF-DIAGNOSIS FUNCTION
:ODE No. 1 25 (SOLENOID VALVE - PRESSUREREGULATORCONTROL)-BPENGINE
r (
TEP
1
-
2
-
3 I
INSPECTION
Disconnect connector from ECU and check if
battery voltage exists at ECU terminal 2T (MTX)
3M (ATX) wire (G/O) with ignition switch ON
In same condition as Step 1, check if battery
voltage exists at solenoid valve connector
terminal-wire (G/O) ACTION
Yes Check ECU terminal connector for poor -
connection
* If OK, replace ECU CT page F-149
+
If not OK, repair or replace connector
No Go to next step
Yes Repair or replace wire (G/O)
No Go to next step
Check if solenoid valve is OK Yes Check for short or open circuit in wiring
w page F-135 from main relay (FUEL INJ relay) to
solenoid valve
No Replace solenoid valve
I I I
23UOFX-077
:ODE No. 26 (SOLENOID VALVE - PURGE CONTROL)
STEP INSPECTION
Disconnect connector from ECU and check if
battery voltage exists at ECU terminal 2X (MTX)
20 (ATX) wire harness (W/L) with ignition switch
ON Yes
No
In same condition as Step 1, check if battery
Yes
voltage exists at solenoid valve connector
terminal-wire (W/L)
No
Check if solenoid valve is OK
Yes
w page F-140
t- No
--
4 ACTION
Check ECU terminal connector for poor
connection
ti If OK, replace ECU c;p page F-149
e
If not OK, repair or replace connector
Go to next step
Repair or replace wire harness (W/L)
Go to next step
Check for short or open circuit in wiring
from main relay (FUEL INJ relay) to
Circuit Diagram
MTX
I-
FROM
BATTERY
FROM
23UOFX-07 9
F-l 02

SELF-DIAGNOSIS FUNCTION F
1
CODE No. 34 (ISC VALVE)
1 ACTION
Yes Check ECU terminal connector for poor
connection INSPECTION
Disconnect connector from ECU and check if
battery voltage exists at ECU terminal 2W (MTX)
3Q (ATX) wire (L/O) with ignition switch ON
c3 If OK, replace ECU
+ If not OK, repair or replace con-
nector w page F-149
No Go to next step
In same condition as Step 1, check if battery
voltage exists at ISC valve connector terminal.
wire (L/O) Yes ) Repair or replace wire (L/O)
No Go to next step
Yes Check for short or open circuit in wiring
from main relay (FUEL INJ relay) to ISC
valve
No Replace ISC valve Check ISC valve for correct resistance
w page F-i 16
Resistance: 1 l-130 [at 20°C(68”F) ]
I 23UOFX-08( I
r C :ODE No. )
41 (SOLENOID VALVE - VICSbDOHC
I
ii
T
I
INSPECTION
ACTION
Check ECU terminal connector for poor
connection
in’
I
* If OK, replace ECU w page F-149
c3 If not OK, repair or replace con-
nector
No Go to next step Disconnect connector from ECU and check if
battery voltage exists at ECU
terminal 2S (MTX)
31 (ATX) wire (B/R) with ignition switch ON
2 In same condition as Step 1, check if battery voltage exists at solenoid valve connector
terminal-wire (B/R)
Check if solenoid valve is OK
w page F-l 18 Yes Repair or replace wire (B/R)
No Go to next step
Yes Check for short or open circuit in wiring
from main relay to solenoid valve
No
Replace solenoid valve
23UOFX-081 3
Circuit Diagram
ATX
ISC VALVE
FROM
BATTERY 4
FROM
L
IGNITION d++n.D,,
SWITCH
MAIN RELAY
(FUEL INJ RELAY) S
4\ ECU
SOLENOID VALVE
i(VICS) [DOHC]
W/R ,,
\
SOLENOID VALVE ,
(PURGE CONTROL)
23UOFX-082
F-i 03

231JOFX-1
FUEL SYSTEM F
INJECTOR
Inspection
Operation check
1. Warm up the engine and run it at idle.
2. Listen for operational sound of each injector with a screw-
driver or a sound scope.
3. If no sound is heard, measure injector resistance.
4. If the injector resistance is OK, check wiring to the injector
and the voltages of the ECU terminals MTX (2A, 2U and
2V) ATX (3A, 3U and 3V).
(Refer to page F-152.)
Injector resistance
1. Disconnect the injector harness.
2. Measure resistance of the injector with an ohmmeter.
Resistance: 12-l 6Q
3. If not as specified, replace the injector.
03UOFX-1
DISCONNECT CONNECTOR
TO RELEASE FU5L PRESSUR
REAR SEAT C
23UOFX-1
OBUOFX-
GRQMMET
INSULATOR
c5
OSUOFX-
Removal
Warning
l Before performing the following operation, release
the fuel pressure from the fuel system to reduce the
possibility of injury or fire. (Refer to page F-121 .)
l When removing the fuel system components, keep
sparks, cigarettes, and open flames away from the
fuel.
1. Disconnect the connectors from the injectors.
2. Remove the injector harness from the delivery pipe.
3. Remove the bolts from the intake manifold.
4. Remove the delivery pipe with the injectors and the pres-
sure regulator.
5. Remove the injectors, grommets, and insulators.
F-131

CONTROL SYSTEM F
SMALL TYPE
03UOFX.20:
03UOFX-20
23UOFX-13
TERMINALS
AANDB
c “.w a ,.1/M rrmrrm
_-
03UOFX-201
ENGINE CONTROL UNIT (ECU)
Removal / Installation
1. Remove the side walls (driver’s side and passenger’s side).
(Refer to page S-94.)
2. Remove the bolts and nuts.
3. Disconnect the ECU connectors.
4. Install a
new ECU in the reverse order of removal.
Inspection
1. Disconnect the ECU connectors.
2. Connect the
SSTs (Engine Signal Monitor and Adapt-
er)
to the ECU as shown,
3. Set the SST (Sheet) on the Engine Signal Monitor with
the specified side fancing up as shown.
Note
l MTX...48 PIN
l ATX...84 PIN
4. Measure the voltage at each terminal.
(Refer to pages F-150 to F-167.)
5. If any ECU terminal voltage is incorrect, check the related
input or output devices and wiring. If no problem is found,
replace the ECU. (Refer to above.)
Caution
l Never apply voltage to SST terminals A and B.
F-l 49

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 F
Ve: Battery voltage
Incorrect voltage
1, -
Always below l.OV
Always Ve
Always below I.OV (Stoplight OK)
Always below l.OV
Always
VB
Always below 25V (Blower fan OK)
Always
VB (Blower fan OK)
Always below 1 .OV
(Electrical cooling fan OK)
Always below 1 .OV (Blower fan OK)
Always
VB (Blower fan OK)
Always below
1 .ov
Always below l.OV Illumination lamp
ON when rear
window defroster
switch ON
Illumination lamp
never ON
(Headlights OK)
Always below l.OV
Always Ve Possible cause
-
l Throttle sensor misadjustment (Refer to page F-169)
l Short circuit in wiring from throttle sensor to ECU terminal 1N l ECU malfunction
l Throttle sensor misadjustment (Refer to page F-169) l Open circuit in wiring from throttle sensor to ECU terminal IN l Open circuit in wiring from throttle sensor to ECU terminal 2D
l Open circuit in wiring from stoplight switch to ECU terminal 10
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
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 10 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 wirina from A/C switch to blower control switch
l Open or short circuit in wiring from fan relay to ECU terminal 1R l ECU malfunction
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 IS
I
l Open or short circuit in wiring from rear window defroster switch to ECU
terminal 1 T
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 or short circuit in wiring from headlight relay to ECU terminal 1U
(Refer to page F-152)
l Neutral switch malfunction (Refer to page F-173) l Clutch switch malfunction (Refer to page F-172) l Short circuit in wirino from ECU terminal IV to neutral or clutch switch
l Neutral switch malfunction (Refer to page F-173) l Clutch switch malfunction (Refer to page F-172) l Open circuit in wiring from ECU terminal 1V to neutral or clutch switch l Poor connection at ECU connector
23UOFX-136
F-l 53