sensor MAZDA PROTEGE 1992 Service Manual

SELF-DIAGNOSIS FUNCTION
:ODE No. 17 (Oxygen sensor-lnvarsion)
r t
INSPECTION
Check if same Code No. is present after per-
forming after-repair procedure CT- page F-704
Check monitor lamp of Self-Diagnosis Checker il-
luminate at idle after warming-up engine and
running it at 2,500-3,000 rpm
for 3 minutes
Check for correct fuel line pressure at idle CT page F-129
Fuel line pressure;
265-314 kPa (2.7-3.2 kg/cm2, 38-46 psi)
{Vacuum hose to pressure regulator
disconnected)
4 Check injectors for fuel teakage c3 page F-132
5
Disconnect each high-tension lead at idle and
check if engine speed decreases equally at each
cylinder
Circuit Oiagram
MTX
I ACTION
Yes 1 Go to next step NO
Check oxygen sensor circuit for poor
connection
r3 If OK, perform troubleshooting
Code No.15
a
If not OK, repair or replace con-
nector u page F-98
Yes Go to next step Note
l A/F mixture rich
No
I Go to Step 5 Note
l A/F mixture is lean or misfire
occurring
Yes
I Go to next step No High pressure
Check if fuel return hose is ciogged or
restricted
+ If OK, replace pressure regulator CT page F-130
c3 If not OK, repair or replace
Yes Replace injector
No Check if water thermosensor is OK
ti if OK, Go to Step 11
c3 If not OK, replace water thermo-
sensor c7 page F-168
CT page F-168
Yes
Go to next step No
Go to Step 8
23UOFX-07
OXYGEN SENSOR
I
R/L
ECU
----------h--M
23UOFX-074
F-l 00

SELF-DIAGNOSIS FUNCTION F
TEP
6
7
8
9
IO
11 INSPECTION
Check for correct fuel line pressure at idle
IV page F-122
Fuel line pressure:
265-314 kPa (2.7-3.2 kg/cm’, 38-46 psi)
(Vacuum hose to pressure regulator
disconnected)
Check intake air system components for air
leakage
Check for misfire of dead cylinder from Step 5
inspection
Check for injector operating sound at idle of
dead cylinder from Step 5 inspection -
Replace injector at dead cylinder from Step 5 in-
spection
CI page F-131
Check if same Code No. is present following
performing after-repair procedure
CT page F-104
Try known good ECU and check if condition
Improves
CT page F-149 Yes
No
Yes If not clogged, check fuel pump
maximum pressure
Go to Step 11
No Replace
--
Yes Repair or replace ignition system
No
Yes
No
Yes
No
T L ACTION
Go to next step
Low pressure
Check fuel line pressure while pinching
fuel return hose
~3 If fuel line pressure quickly in-
creases, check pressure regulator
v page F-129
c3 If fuel line pressure gradually in-
creases, check for clogging be-
tween fuel pump and pressure
regulator
CT page F-126
Go to next step
Go to next step
Check for battery voltage at injector
connector terminal-wire (W/R)
L3 If Yes, replace injector c7 page F-131
+ If No, check wire harness for short
or open
Go to next step
Removed injector at fault
Circuit Diagram
ATX
OXYGENSENSOR
R/L
ECU
-------------- ---
BILG
23UOFX-07
F-10'

SELF-DIAGNOSIS FUNCTION F
SWITCH MONITOR FUNCTION
Individual switches can be inspected by the SST (Self-Diagnosis checker).
Note
l The TEN terminal of the diagnosis connector must be grounded and the ignition switch ON
(engine stopped).
l If either of the switches remain activated, the monitor lamp will be illuminated.
ECU
NEUTRAL SWITCH (MTX)
CLUTCH SWITCH (MTX)
=d-’ 1
BATTERY
INHIBITOR SWITCH (ATX)
STOPLIGHT SWITCH (MTX)
HEADLIGHT SWITCH MONITER LAMP
REAR WINDOW (SELF-DIAGNOSIS CHECKER)
DEFROSTER SWITCH
AIC SWITCH
BLOWER SWITCH
THROTTLE SENSOR asp-
- _
COOLING FAN SWITCH
03UOFX
Switch
Clutch switch
Neutral switch (MW
(M-W Self-Diagnosis Checker (Monitor lamp)
Light ON Light OFF Pedal released Pedal depressed
In gear Neutral Remark In gear
Clutch pedal released
Inhibitor switch
(ATX) L, S, D or R range
N or P range -
Throttle sensor Pedal depressed (Not fully) Pedal released/fully depressed -
Stoplight switch
Pedal depressed Pedal released -
Headlight switch
ON
OFF Headlights/parking lights: ON
Blower switch
ON
OFF Blower switch at 2nd or
above position
AIC switch
ON OFF Fan speed control at 1st po-
sition
Rear window defroster
switch ON
OFF -
Water thermoswitch Fan operating Fan not operating -
23UOFX-084
F-l 05

SELF-DIAGNOSIS FUNCTION
Inspection Procedure
1. Connect the SST (System Selector) to the diagnosis con-
nector.
2. Set the switch @ to position 1.
3. Set TEST SW to SELF-TEST.
03UOFX.090
MONITOR LAMP
T
03UOFX-091
Procedure
4. Connect the SST (Self-Diagnosis Checker) to the System
Selector and a ground.
5. Set the select switch of the Self-Diagnosis Checker to posi-
tion A.
6. Turn the ignition switch ON.
7. Check if Monitor Lamp illuminates when each switch is made
to function as described below.
Caution
* If either of the switches remain activated, the mon-
itor lamp will be illuminated.
l Do not start the engine.
I
I Set conditions to deactivate each switch l All accessories OFF l Transaxle in neutral l All pedals released NO
-
Verify that monitor lamp does not illuminate
YES
Check each switch as described Check each switch and related wire harness
*Clutch and Neutral CT- pages F-l 72,173
switch
*Throttle sensor w page F-169 l Stoplight switch c7 Section T l Headlight switch c7 Section T l Rear defroster switch T;P Section T l Blower switch [r+ Section T
l Inhibitor switch a Section K l A/C switch 0 Section U l Water thermoswitch c7 Section E
23UOFX-OS!
Neutral and Clutch switch (MTX)
Shift transaxle into gear
Check that monitor lamp illuminates with clutch pedal
released
YES NO PC: l Neutral switch malfunction a page F-173 l Clutch switch malfunction w page F-172
*Open circuit in related wire
harness
l ECU terminal 1 V voltage
incorrect w page F-152
l ECU malfunction
Depress clutch pedal
Check that monitor lamp does not illuminate
Return transmission to neutral PC:
*Clutch switch malfunction w page F-172
23UOFX-088
F-l 06

SELF-DIAGNOSIS FUNCTION
Throttle sensor
Depress accelerator pedal (not fully) and check that
monitor lamp illuminates
YES NO
PC: *Throttle sensor malfunction CT page F-169
*Short circuit in wire harness
from throttle sensor to ECU
*ECU terminal 1 N (MTX) 1T
(ATX) voltage incorrect CT page F-150
l ECU malfunction
Depress acceleration pedal fully and check that monitor
No : PC: *Throttle sensor malfunction w page F-169
lamp does not illuminate *Open circuit in wire harness
from throttle sensor to ECU
YES *ECU terminal 2L (MTX) or 21
(ATX) voltage incorrect a page F-154
Throttle sensor OK
Release accelerator pedal
23UOFX-090
Stoplight switch
Depress brake pedal
Check that monitor lamp illuminates
YES
Stoplight switch OK
Release brake pedal NO
PC: *Stoplight switch malfunction w Section T
*Open circuit in wire harness
1
from stoplight switch to ECU
*ECU terminal 10 (MTX) 1Q
(ATX) voltage incorrect CT page F-l 52
l ECU malfunction
23UOFX-091
Blower switch
---
Turn blower switch to 2nd or higher position
Check that monitor lamp illuminates
YES
Blower switch OK NO
__L PC: *Blower switch malfunction
*Open circuit in wire harness
from blower switch to ECU
l ECU terminal 1 S (MTX) 1 P
(ATX) voltage incorrect
l ECU malfunction p Section T
w page F-152
23UOFX-092
F-l 08

.-
IDLE SPEED CONTROL (ISC) SYSTEM I-
IDLE SPEED CONTROL (ISC) SYSTEM
DESCRIPTION
BP SOHC
AIR VALVE THROTTLE SENSOR
CLUTCH SWITCT (MTX)


‘IS PRESS/URE SWITCH ‘x.

. , SIS CONNECTt
(TEN TERMINAL)
DISTRIBUTOR
INHIEITOR SWITCH (ATX)/
NEUTRAL SWITCH (MTX) 3R
To improve idle smoothness, the ISC system controls the intake air amount by regulating the bypass air amount
that passes through the throttle body. This system consists of the ISC valve, air valve, ECU and input devices.
F-115

F EXHAUST SYSTEM
EXHAUSTSYSTEM
COMPONENT PARTS
Removal / Inspection / Installation
1. Remove in the order shown in the figure.
2. Check the exhaust component parts and repair or replace if necessary.
3. Install in the reverse order of removal.
29149
(3.0-5.0, 22-36) .
^ _ ^.S_
T,
nrrwCE
O-55 (4.1-5.6, 30-41)
N.m (m-kg, ft-lb
23UOFX-1
1, Main silencer
Inspect for deterioration and restriction
2. Pre-silencer
Inspect for deterioration and restriction
3. Catalytic converter
Inspect for deterioration and restriction 4. Front pipe assembly
Inspect for deterioration and restriction
5. Exhaust manifold
Inspect for deterioration and cracks
6. Exhaust manifold insulator
7. Oxygen sensor
Inspection . . . . . . . ..*...................... page F-171 --
‘Y’
F-l 36

EVAPORATIVE EMISSION CONTROL SYSTEM t
EVAPORATIVE EMISSION CONTROL SYSTEM
DESCRIPTION
/ /
ENGINE ENGINE
CONTROL CONTROL - INPUT - INPUT
UNIT UNIT
- -
SOLENOID VALVE SOLENOID VALVE k k / /
CHECK VALVE CHECK VALVE
(TWO-WAY) (TWO-WAY)
CHARCOAL CHARCOAL
CANISTER CANISTER
CHECK-AND-CUTC CHECK-AND-CUTC
VALVE VALVE
SEPARATOR SEPARATOR TO ENGINE TO ENGINE SIGNALS
The evaporative emission control system consists of the separator, the check-and-cut valve, the two-way
check valve, the charcoal canister, the purge control solenoid valve, the engine control unit (ECU), and the
input devices. The amount of evaporative fumes introduced into the engine and burned is controlled by the
solenoid valve to correspond to the engine’s operating conditions. To maintain best engine performance,
the solenoid valve is controlled by the ECU.
Operation
.._ The solenoid valve (purge control) is controlled by duty signals from the ECU to perform purging of the char-
coal canister. Purging is done when these conditions are met:
(1) After warm-up
(2) Driving in gear
(3) Accelerator pedal depressed (idle switch OFF)
(4) Oxygen sensor functioning normally
F-l 39

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

CONTROL SYSTEM F
CONTROLSYSTEM
PREPARATION
SST
49 9200 162
Engine Signal
Monitor
49 HO18 9Al
Self-Diagnosis
Checker
49 GO1 8 904
Sheet For
inspection of
ECU
For
inspection of
oxygen sensor
For
inspection of
ECU 49 GO18 903
Adapter
harness
49 BO19 9AO
System
Selector For
inspection of
ECU
For
inspection of
oxygen sensor
03UOFX-20
F-l 47