1992 MAZDA PROTEGE ECU

SELF-DIAGNOSIS FUNCTION
:ODE No. 08 (AIRFLOW METER)
TEP INSPECTION ACTION
1 Check airflow meter circuit for poor connection Yes Repair or replace connector
No Go to next step
2 Check if Code No.10 is also present Yes Check for open circuit in wiring from
airflow meter terminal-wire (BILG) to
ground
Go to next step
3 Check if resistance of airflow meter is OK
4 Check wire harness between airflow meter and
Repair or replace wire harness
5 Check if ECU terminals voltages are OK Yes Replace ECU CT= page
F-149
MTX...2D, 2K and 20
ATX... 2B, 21 and 3D a page
F-152 No Check for short circuit in wiring from
airflow meter to ECU
23UOFX-058 .-
.- ,
F-90

SELF-DIAGNOSIS FUNCTION F
Circuit Diagram
MTX
I
ECU FROM CIRCUIT-
A
p) LhmGb
L”
ZrJ \zVJ / OPENING RELAY
----___--_- -====
_--___------
I 1 IW I I il I I DIAGNOSIS CONNECTOR
WATER
THERMOSENSOR -. BILG I
LG
+/
+ II-
RIB B/BR 1 R LGlR LG I
LIW I
BlLG
I 0
0 4,
9,
I
-- --
_- -- == =z L\. $k
= = 4k $
==
E G C F D A B
+/
BILG
BIBR
L-de
,, BIBR
\ 4,
AIRFLOW METER
23UOFX-05
WATER
-S-“Ce)..r\ECL,Cr\D BILG I
+R
RIB BIER ;
0 BlLG _
4, I
I
I
-1
LG
DIAGNOSIS CONNECTOR
LGlR ”
I=
1
23UOFX-06
F-91

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

SELF-DIAGNOSIS FUNCTION F
Circuit Diagram
MTX
FROM CIRCUIT-
OPENING RELAY
DIAGNOSIS CONNECTOR
WATER
THERMOSENSOR
f
BlLG I
4 I,
RIB BlBR I R
LGIR LG 1,
BlLG I
I B
0
I
I
= = $k $&
==: -zz $k $h
== = = $& $>
==
E G C F D A B
1 LG
-
AIRFLOW METER
23UOFX.06:
ATX
J
>
I FROM CIRCUIT,;
#wr.r..*..n -s. .
I
ECU
em--------------
- --___ _-------- - - Ut-CNINb titLA
WATER
THERMOSENSOR L/W
I
DIAGNOSIS CONNECTOR
LG
I
1:
RIB BIER ,
0
23UOFX-06:
F-93

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

SELF-DIAGNOSIS FUNCTION F
Circuit Diagram
MTX
I
L/W I
I FROM CIRCUIT-
+ OPENING RELAY
LG
DIAGNOSIS CONNECTOR
BILG I
p,
+ ,
RIB BlBR 1 R LGIR LG
LIW
BILG
I B
, 0
a I
I
WATER /c
== //& $k $k $&
z-z 1== == = = $k
== $
THERMOSENSOR
+$ E G C F D A B
BILG
BlBR
kr%J
,, BIBR,
> 0 I
AIRFLOW METER
INTAkE AIR THERMOSENSOR
23UOFX-06:
ATX
I
ECU
WATER
THERMOSENSOR
I BIBR BlLG I
4
I R
RIB BlBR ,
0 BILG _
0 I
I
I
== p+ 9+
fT ,= JJk
==
E G C F
BILG
I
LG
DIAGNOSIS CONNECTOR
LGlR t”-cE-
AIRFLOW METER
23UOFX-06I
F-95

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