1992 MAZDA PROTEGE coolant temperature

F TROUBLESHOOTING GUIDE
10
ROUGH IDLE/ENGINE STALLS AT IDLE - AFTER WARM-UP
DESCRIP-
rlON
*Engine runs normally at idle during warm-up but engine stalls or vibrates excessively after warm-up [TROUBLESHOOTING HINTS]
3 Idle speed control system malfunction @ Air/Fuel mixture too rich
3 Air/Fuel mixture too lean l Fuel injection control malfunction l Air leakage (Correction for coolant temperature)
*Low fuel line pressure @ Poor ignition
@ Low engine compression CT= page F-83
Check ECU terminal 1F voltage CT page F-150
Specification: Battery voltage
(Ignition switch ON)
* If OK, replace ECU w page F-149 * If not OK, check wiring between
ECU and Self-Diagnosis Checker
Check for cause LY page F-151
Vacuum: More than 450 mmHg (17.7 inHg)
I.:.F page F-109
F-46

F TROUBLESHOOTING GUIDE
13 HIGH IDLE SPEED AFTER WARM-UP
DESCRIP- l Idle speed excessive after warm-up
TION [TROUBLESHOOTING HINTS]
Excessive intake air supplied to engine
@I Throttle valve not fully closed
@ Idle speed control malfunction
l Air valve not closed l ISC valve stuck
l ISC valve connector disconnected l A/C, P/S, or E/L signal sent to ECU l Incorrect coolant temperature signal
stalled and operates freely w page F-l 14
@ If OK, go to Step 2
+ If not OK, clean, adjust or replace w page F-l 14
* If contaminated, clean throttle body Dashpot set speed: + If not contaminated, replace throttle
..*.............*..,........,... Approx. 3,000 rpm w page F-109
BP SOHC . . . . . . . . . . . . . . . . . . . . . . Approx. 2,700 rpm
BP DOHC . . . . . . . . . . . . . . . . . . . . . . Approx. 3,500 rpm
w page F-83
Check ECU terminal 1F voltage w page F-150
Specification: Battery voltage
(Ignition switch ON)
e If OK, replace ECU w page F-149
c3 If not OK, check wiring between
ECU and Self-Diagnosis Checker
Check for cause (Refer to specified
check sequence) w page F-108
W: SELF TEST
and Self-Diagnosis Checker
F-50

F PRESSURE REGULATOR CONTROL SYSTEM
PRESSURE REGULATOR CONTROL SYSTEM (BP ENGINE)
THERMOSEN
SOLENOID VALVE
(PRESSURE REGULATOR CONTROL)
(FROM DELIVERY
FUEL
(TO FUEL TANK)
Engine
BP SOHC
BP DOHC Coolant temperature
Above 90% (194*F) Operating condition
Intake air temperature
Above 50°C (122OF)
Above 58OC (136OF) Engine condition . Operating time (set)
Throttle valve fully closed
Approx. 120
or no load condition
Approx. 60
#.nr IAt-%/ 4 7
To prevent percolation of the fuel during hot restart idle, vacuum to the pressure regulator is momentarily
cut, and the fuel injection pressure is increased to slightly more than 284 kPa (2.9 kg/cm2, 41.2 psi).
F-l 34

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
Ve: Battery
arminal Input Output Connection to lest condition Correct voltage Remark
2A - - Ground (Injector) Constant ov -
28 - - Ground (Output) Constant ov -
2c - - Ground (CPU) Constant ov -
2D - - Ground (Input) Constant ov -
2E 0 Distributor Ignition switch ON
Approx. OV
(Ne-signal) or 4.5-5.5V -
Idle Approx. 2V
2F - - - - - -
2G 0 Distributor Ignition switch ON Approx. OV
(G-signal) [DOHC] or 4.5-5.5V
Idle Approx. 1.5V
2H 0 Ground (California) Constant ov
-
Main relay Ignition switch ON Va
(Canada)
21 - - - - - -
2J 0 Open Constant Approx. l-29 -
2K 0 Throttle sensor Constant 4.5-5.5v
(ATX)/Airflow meter
-
2L 0 Throttle sensor
(Power switch) Accelerator pedal released
Accelerator pedal fully depressed Approx. 4.5~5%
ov -
2M 0 Throttle sensor Accelerator pedal released
Accelerator pedal fully depressed Approx. 0.5V
Approx. 4.OV -
2N 0 Oxygen sensor Ignition switch ON ov
Idle (Cold engine) ov
Idle (After warm-up) O-l .ov -
Increasing engine speed (After warm-up) 0.5-I .ov
Deceleration o-0.4v
20 0 Airflow meter Ignition switch ON Approx. 3.8V
-
Idle Approx. 3.3V
2P 0 Intake air ther- Ambient air temperature 20% (68OF) Approx. 2.5V Built in airflow
mosensor meter
2Q 0 Water thermo- Engine coolant temperature 20% (68’F) Approx. 29
_
sensor
After warm-up Below 0.5V
2R - - - - -
- 711 ICIFX-12 voltage
_““_. ,. .I 7
1 r u-
r-i Ll r
2Y 2w 2u 2s 20 20 2M 2K 21 2G 2E 2~2 2A 1U 1s 1Q 10 lft,j ,K ,, ,G ,E ,c ,A
22 2x 2v 2T 2R 2P 2N 2L 2J 2H 2F 2D 28
IV 1T fR 1p 1N 1L 1J ,H IF ID ,B
F-l 54

F CONTROL SYSTEM
Ve: Battery voltage
erminal Input Output Connection to
Test condition Correct voltage Remark
2s 0 Solenoid valve
Engine speed below 5,000 rpm ov VICS: Variable In-
(VICS)
Engine speed above 5,000 rpm
VB ertia Charging
System [DOHC]
2T 0 Solenoid valve
60 [DOHC]/120 [SOHC] seconds after ov
(Pressure regula- engine started when engine coolant tem-
tor) [BP] perature above 90% (194OF) and intake
-
air temperature above 58% (136’F)
[DOHC]/50% (122OF) [SOHC]
Other condition at idle
Ve
2u
0 Injector (Nos. 1, 3) Ignition switch ON V0 *Engine Signal
idle
VB Monitor: Green
Engine speed above 2,000 rpm on de-
VB and red lamps
flash
celeration (After warm-up)
2v 0 Injector (Nos. 2, 4) Ignition switch at idle
Ve
idle
VI3
Engine speed above 2,000 rpm on de-
VB celeration (After warm-up)
2w
0 ISC valve Ignition switch ON Approx. 7V
-
Idle
Approx. QV
2x 0 Solenoid valve Ignition switch ON
VB (Purge control) -
Idle VB
2Y - - - - - -
23UOFX-1:
I r
U----l l-l
Ll I-
2y
2w 2u 2s 20 20 2M 2K 21 23 2E 2C 2.4 1U 1s 10 10 1M 1K 11 1G 1E 1~ IA
2z 2x 2’4 2T 2R 2P 2N 2L 2J 2l-i 2F 2D 28 IV 1T 1R lp IN IL 1J 1~ 1F If) 1~ -/
F-l 56

F CONTROL SYSTEM
VB: Battery voltage
erminal Input Output Connection to
Test condition Correct voltage Remark
28 1 0 )
1 Airflow meter Ignition switch ON Approx. 3.8V
-
2c 0 Oxygen sensor
2D 0 Fan switch Idle Approx. 3.3V
Ignition switch ON ov
Idle (Cold engine)
ov
Idle (After warm-up) O-l .ov -
increasing engine speed (After warm-up) 0.5-I .ov
Deceleration o-0.4v
Fan operating (Engine coolant tempera- ov
ture over 97OC (207°F) or diagnosis con-
nector terminal TFA grounded) -
2E 0 Water thermo-
sensor Fan not operating (Idle) VS
Engine coolant temperature 20% (68OF)
After warm-up Approx. 2.5V f&ition switch
Below 05V
2F , 0 , , Throttle sensor , Accelerator pedal released
Accelerator pedal fully depressed
2G 0
2H 0 ATF thermosensor -30°C (-20°F) -150°C (302OF) Approx. 4.9%1.12V Ignition switch
ATF
Temp 20% (68OF) Approx. 4.6V ON
130% (266OF) Approx. 1.54V
Hold switch Switch debressed ov Ignition switch
i I I
Switch released Va ON
21 0 Throttle sensor Constant 4.5-5.5v Ignition switch
ON
I , I 2J 0 Distributor Ignition switch ON Approx. OV
(G-signal) [DOHC] or 5V _-
Idle Approx. 1.5V
2K 0 Intake air ther- Ambient air temperature 20% (68’F) Approx. 2.5V Built in airflow
mosensor meter
2L - - - -
- -
2M 0 Pulse generator Engine running at idle (N range) Above 0.6V
-
(IN)
Engine stopped (Ignition switch ON) ov
2N Pulse generator Constant ov
ground
20 0 Solenoid valve ignition switch ON Va
(Purge control) -
Idle Va
2P 0 Hold indicator Hold mode Below 2V Ignition switch
ON
Normal mode VB
23UOFX-1
1 Ul Iv
I u1
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4-
F-l 62

F CONTROL SYSTEM
srmina
3A
38
3c
3D
3E
3F
3G
3H
31
3J
3K
3L
3M
3N
30
3P
3Q
3R
3s
3T I input Output Connection to
Test condition Correct voltage Remark Battery voltage t
- -
Ground (Injector) Constant OU -
- -
Ground (Output) Constant OU -
- -
Ground (CPU) Constant OU -
- -
- Ground (Input) Constant ov
0 Inhibitor switch
D range VB Ignition switch
(D range) ON
Other ranges ov
0 DRL relay Parking brake pulled with ignition switch
l DRL: Daytime
(Canada) ON (DRL OFF) Va
Running Lights
Idle (DRL ON) Below 2.5V 0
Inhibitor switch
(L range) L range
Other ranges VB
ov Ignition switch
ON
0 Inhibitor switch
(S range) S range
Other ranges Va
ov Ignition switch
ON
_-__. - -. -
0 Solenoid valve Engine speed below 5,000 rpm Below 1.5V WCS: Variable In-
(VICS)
Engine speed above 5,000 rpm VB ertia Charging
System [DOHC]
- - -
- - -
- -
- - -
- - -
- - -
0 Solenoid valve 60 [DOHC]/120 [SOHC] seconds after Below 1.5v
(Pressure regula- engine started when engine coolant tem-
tor) [BP] perature above 90% (194*F) and intake
-
air temperature above 58% (136OF)
[DOHC]/50”C (122“F) [SOHC]
Other condition at idle Va
- - - - - -
- -
-
A- - -
- -
- I -
0 ISC valve Ignition switch ON VS
l Engine signal
Monitor: Green
I I Idle I
Approx. 1 OV and red lamps
flash
I
-
- - - -
-
- - - -
- - - - - -
23UOFX-1’
‘) )
U- r, )
IJ- l-1
I 1 r
3Y I3W I3U [3S13d3&M13K 31 13Gj3EI 3C
I3A 20/2M;2K( 21 12G(2E12C12A 1 U 11 Sll o]lOll MI1 K 1 I (1 G(1 E[ 1
C 11 A
32 13x [ 3V(3~(343~I3N[3~ 3~(3~(3~13~ 136 2P12N(2L[2J12H(2F(2D126 iv I~TI~RI~P(~NIIL i~(lii(l~I lo(le
.
F-l 64