1990 MAZDA 232 coolant

E OUTlANE
TWO-STAGE THERMOSTAT (BP DOHC TURBO)
MAIN VALVE
SINGLE-STAGE THERMOSTAT
(AMBIENT fEMP. -20% (4*f))
NTRANCE PORT TEMP
GINE EXIT PORT TEMP.
- 100 km/h
60 kndh
(63 mph) ~~~~~ (38 mph)
TWO-STAGE THERMOSTAT
A sub-valve is incorporated in the thermostat to stabilize the coolant temperature in the engine, to improve
cold weather performance, and to reduce heater output temperature fluctuations as noted in the diagram.
Operation
Stage 1
During cold weather operation, 83.5*C [182°F]-86.50C [t 88OF] only the sub-valve opens to control the
engine coolant temperature.
Stage 2
During normal operation, 86.5OC (1 88°F)-89.50C (I 93OF) the main valve opens to permit increased coul-
an: flow through the radiator.
E-6

E OUTLINE
ELECTRIC COCUNG FAN SYSTEM (BP DOHC TURBO)
System Circuit
I I
WITH A/C
r----‘-- -___- ---------.--------;
ADDITIONAL
FAN
MOTOR
I
II 1 A/C RELAY
RAD1ATdTHERMOSWITCH
ABOVE 105% I221 OF-): ON +IIAGNOSlS
CONNECTOR
WATER
THERMOSWlTCH
ABOVE 97% (207OF): ON
Operation 1. When the coolant temperature exceeds 97OC (207*F), the water thermoswitch turns ON to close the No.7
relay, and connects the + I and -1 terminals of the fan motor
connector. The fan motor turns at low
speed (about 1,660 rpm).
2. When the coolant temperature exceeds 105OC (221 OF), the radiator thermoswitch turns ON, to close the
No.2 and No.3 relays, and connects
the +2 and -2 terminals of the fan motor connector. The fan mo-
tor turns at high speed (about 2,200 rpm).
3. if the vehicle is equipped with air conditioning, the cooling fan motor operates whenever the
NC switch
and the blower switch are on, regardless of
the coolant temperature. Also, when the A/C switch and the blower switch are on, the A/C retay closes
to operate the additional fan
motur.
Note
l The water thermoswitch and the cooling fan reIay are normally-open switches.
Checking cooling fan operation 1. Jump across the TFA and the GND terminals
of the diagnosis connector with a jumper wire.
2. Turn the ignition switch to ON and verify that the cooling fan operates smoothly.
Note
l When the water thermoswitch connector is disconnected, the cooling fan wiif not operate.
E-8

E ELECTRIC COOLING FAN SYSTEM
ELECTRIC COOLING FAN SYSTEM (BP
DUHC TURBO)
SYSTEM ClRCUIT
r
WITH A/C
r-- _______ ------
I ADDITIONAL
1 FAN
I PRESSL
SWITCH
I WATER
THERMOSWfTCtl
ABOVE 87OC (207OF): ON
RADlATOjl THERMOSWITCH
ABOVE 105*C (221 “I=): ON
8 93GOEX-719
-
%
J--- QY- -THERMOME?ERsi-=i
--
--------L-
93GOEX-7 i 2
E-10 SYSTEM INSPECTION
1. Jump across the test fan (TFA) terminal and the ground
(GN D) terminal of the diagnosis connector.
2. Turn the ignition switch ON and verify that the fan operates.
If the fan does not operate, inspect the cooling fan system
components and wiring harness.
3. Remove the radiator cap and place a thermometer in the
radiator filler neck.
4. Start the engine.
5. Verify that the fan operates when the coolant temperature
reaches approx. 97*C (207°F).
If it does, check the water thermoswitch.
(Refer to page
E--i I.)

FAN MOTOR, WATER THERMOSWITCH E
93GOEX-71:
93GOEX-714
93GOEX-720
tNSPECTlON
Single-speed Type (For BP SOW MTX)
I. Verify
that the battery is fully charged.
2. Disconnect the fan motor connector.
3. Connect the battery and an ammeter to the fan motor
con-
nector.
4. Verify that current is as specified.
Current (A): 6.6 k 1
5. If current is not within specification and/or the fan does not
turn smoothly, replace the fan motor.
Two-speed Type (Except BP SUHC MTX)
I. Verify that the battery is fully charged.
2. Disconnect the fan motor connector.
3. Connect the battery and an ammeter to the fan motor con-
nectors for low-speed inspection.
4. Verify that the fan motor operates smoothly at the standard
cu vent.
Current (A): 8.8 + 10% max.
5. Connect the battery, an ammeter, and switch to the fan mo-
tor connectors for high-speed inspection.
6. Verify that the fan motor operates smoothly
at the standard
current or less with the switch ON.
Current (A): 13.3 + 10% max.
7. If not as specified, replace the fan motor.
WATER THERMOSWITCH
(BP DOHC TURBO)
INSPECTlUN
I . Place the switch and a thermometer in water.
2. Heat the water gradually and check continuity of the switch
with an ohmmeter.
Coolant temperature OC (OF) 1 Contrdy
I
More than 97 (207) Yes
Less than 90 (194)
NO
3. If not as specified, replace the water thermoswitch.
93GOEX.715

F2 CONTROL SYSTEM
KNOCK CONTROL SYSTEM [BP TURBO]
This svstem retards the ignition timina when enaine knocking occurs because of usage of low octane fuel, etc.
1NTAKE
MANIFO
KNOCK SENSOR
(INSTALLED BETWEEN No.2 AND
No.3 CYLINDER)
IGNITER
KNOCK iX?NTROL
UNIT
Operation
When the engine vibrates, the knock sensor generates a slight voltage signal that is the sent to the knock
control unit. The knock control unit determines whether the signal is a knocking signal. If it is a knocking
signal, the ignition spark is retarded according to the intensity of the knock to a maximum of 4O.
Inhibition of spark retardation
In order to improve drivability and fuel economy, the ECU inhibits the above spark retardation when the
‘engine load Ls light, the coolant temperature is below O°C (32OF), the engine is cranking during engine test
conditions.
Note
l The knock ~ensur and knock control unit cannot be inspected individually.
When a matfunction code number 05 is indicated, replace the knock controt unit or sensor
only after inspecting the related wiring and connectors.
F2-22

CONTROL SYSTEM F2
t OXYGEN SENSOR [BP TURBO]
I
CERAMlC HEATER
93GOF2-733
Because the temperature of the exhaust gas is inherently low in turbocharged engines, the BP Turbo model
uses a rapid heating ceramic heater to detect the air/fuel ratio,
PRESSURE REGULATOR CONTROL SYSTEM [BP TURBO]
PRESSURE
REGULATOR
I SOLENOID VALVE
(PRESSURE REGULATOR CONTROL)
FUEL
+ (FROM
DELIVERY PIPE1
II
FUEL INJ I
RELAY
(MAIN REU\Y)
I
II Ir
-__. _ - -’ VACUUM
CT0 DYNAMIC
Ill
CHAMBER)
BATTERY -
c
FUEL
(TO FUEL TANK)
nme*rn -.-a
To prevent percolation of the fuel during hot restart idle, vacuum to the pressure regulator k cut for 180
sec., and the fuel injection pressure is increased to slightly more than 284 kPa (2.90 kg/cm’, 41.2 psi).
Operating condition
l Coolant temperature: Above 90°C (194OF)
l Intake air temperature: Above 58OC (136OF)
g No-load condition
FZ-23

TURSUCHARGER CONTROL SYSTEM F2
Removal I InstaIlation
Caution
l Be carefui of following points after turbocharger removal.
l Do not carry the turbocharger by the actuator rod or actuator hose.
l Do not drop the turbocharger.
l Set the turbocharger down with the turbine shaft horizontal.
9 Cover the intake, exhaust, and oil passages to prevent dirt or other materia1 from entering.
l Use the specified new studs when installing the turbocharger.
1. Disconnect the negative battery cable.
2. Lift up the vehicle.
3.
Remove the undercover.
4. Drain
the engine coolant.
5. Remove in
the order shown in the figure.
6. fnstall in the reverse order of removat, referring to Installation Note.
7.8-l 1 N-m (80-l 10 cm-kg, 69-95 in-lb)
G I’
/
43-61 (4.4-6.2, 3245)
36-42 (3.94.3, 28-
7.8-1 1 N-m (80-110 cm-kg, 6
cm-kg, 69-95
indb)
26-31
12.7~g-2. 20-231
w
19-26 (l-9-2.6, 14-19)
7.6-17 N-m (80-7 t d cm-kg, 69-95 in-lb)
N-m (m-kg, Mb]
I 93GOF2-762
F2-47

F2 CONTROLSYSTEM
erminat Input ’ Output Connected to Test condition Correct voltage Remark
1N 0 I Throttle sensor Accelerator pedal released &low l.OV j Ignition switch
(Idle switch)
Accelerator pedal depressed Approx. 12V *N
IO I 0 j [ Stoplight switch Brake pedal released Betow 1 .OV -
1P j 0 1 i P/S pressure lgnitlon switch ON Approx. 12V
I
switch
f/S ON at idle Below 1 .UV
I
P/S OFF at idle Approx. 12V -
I
to 0 A/C switch A/C switch ON
NC switch OFF Beiow 2.W ignition switch
ON and blower
Approx* t2V motor ON
i
1R 0 Electric fan switch Fan operating (Engine coolant tempera- Betow l.OV
ture over 91 *C (t96*F) or diagnosis con-
-
nector terminal TFA grounded)
Fan not operating (Idle) Approx.. f 2V
IS 0 Blower control Blower controf switch OFF or 1st position Approx. 13 Ignition switch
switch
Blower control switch 2nd or higher po- Below 7 .OV ON
sition
IT
Cl Rear window
defroster switch Rear window defroster switch OFF
Rear window defroster switch ON Below 1 .OV Ignition switch
Approx. 12V ON
1u 3 Headlight switch Headlights ON Approx. 12V
-
Headlights OFF Below 1 .OV
-Iv Cl ’ Neutral/Clutch
Neutral position or clutch pedal Below I .OV
switches
depressed
Others Approx. 12V
l-7 I r
f
2V 2W 2U 25 20 20 2M 2K 21 2G IZE 2C 2A IU IS 10 10 IM 1K 11 1G rE tC IA
22 2X (2V 2T 2R 2P 2N 2L 2J 2H’ZF 20 2B fV 1T 1R IP IN 1L 7J III If ItI 1B l F2-62