check engine MAZDA 626 1987 Workshop Manual

ANTI-LOCK BRAKE SYSTEM (ABS) 1 1
86U11X-190
86U11X-191
76G11X098
Inspection of Pressure Reduction
1. Check that the battery is fully charged.
2. Jack up the vehicle and support it with safety
stands.
3. Release the parking brake.
4. Check the wheel for brake drag while turning it by
hand.
5. Connect terminal wires (GB) and (B) of the check
connector with a jumper wire.
6. Have an assistant depress the brake pedal; then
verify that the wheel cannot be turned.
7. Run the engine for 10 sec, and stop it.
8. With the brake pedal depressed, turn the ignition
switch ON.
9. With the brake pedal still depressed, check that the
wheel can be turned intermittently (when pressure-
reduction is operating).
Right'F Left F Rear Pressure reduction
Ignition switch ON OFF
1 05 1 sec sec sec
J
10. Check operation at the remaining wheels.
11. If not operated correctly, check the warning light
and brake light switch circuit for proper operation.
Inspection of Proportioning Valve
Note
The proportioning valve is built into the hy-
draulic unit.
1. Disconnect the flexible hose from the brake pipe;
then connect one pressure gauge to the front brake
pipe, the other to the rear brake pipe.
Note
Use a pressure gauge [9,810 kPa (100 kg/cm2,
1,422 psi)].
86U11X-193
11—95

ANTI-LOCK BRAKE SYSTEM (ABS) 1 1
CONTROL UNIT CIRCUIT
Inspection of Control Unit Circuit
1. Start the engine, and run it for 10 seconds.
2. Disconnect the connectors from the control unit. Check the connector at the harness side as shown
in the table below.
Terminal Connection or measured item Check item Tester connection Condition Voltage or
resistance

Q-01 11 -pins
2A (W),
2B (R)
Wheel speed sensor
Left front Voltage (AC) 2A (W)
- 2B
(R) Turn wheel
1
revolution
per second More than 0.25V (AC)
Q-01 11 -pins
2A (W),
2B (R)
Wheel speed sensor
Left front
Resistance
2A (W)
- 2B
(R)

—
800-1.2000
Q-01 11 -pins
2C (Y),
2D
(0)
Wheel speed sensor
Right front Voltage (AC) 2C (Y)
-
2D (0) Turn wheel
1
revolution
per second More than 0.25V (AC)
Q-01 11 -pins
2C (Y),
2D
(0)
Wheel speed sensor
Right front
Resistance
2C (Y)
-
2D (0)

—
800-1,2000
Q-01 11 -pins 2E (YG),
2F (YL)
Wheel speed sensor
Left rear Voltage (AC) 2E (YG)
- 2F
(YL) Turn wheel
1
revolution
per second More than 0.25V (AC) Q-01 11 -pins 2E (YG),
2F (YL)
Wheel speed sensor
Left rear
Resistance
2E (YG)
- 2F
(YL)

—
800-1,200G
Q-01 11 -pins
2H (G).
2J
(L)

Wheel speed sensor
Right rear Voltage (AC) 2H (G)
- 2J
(GR)
Turn wheel
1
revolution
per second More than 0.25V (AC)
Q-01 11 -pins
2H (G).
2J
(L)

Wheel speed sensor
Right rear
Resistance
2H (G)
- 2J
(GR)

_
800-1,200fl
Q-01 11 -pins
21 (GR) Low pressure switch Continuity 21 (GR)
-
Ground
—
Continuity
Q-01 11 -pins
2K (LB) High pressure switch Continuity 2K (LB)
-
Ground
—
Continuity
Q-01 11 -pins
2L (WB) Alternator output Voltage 2L (WB)
-
Ground Run engine Approx.
14V

Q-01
17-pins
A (WG) Brake light switch Voltage A (WG)
-
Ground Depress brake pedal 12V
Q-01
17-pins
B (RY) Motor Continuity B (RY)
—
Ground
—
Continuity
Q-01
17-pins
C (LO) Motor relay Resistance C (Lo)(© test-lead)-J
—
Approx. 60—700
Q-01
17-pins
D (GR) Check connector Continuity D (GR)
- A
(GR, Q-07)
—
Continuity
Q-01
17-pins
E (BL) Fail-safe relay Resistance E (BL)
- G
(BG)
—
Approx. 70-800
Q-01
17-pins
F (LY) Warning light Continuity F (LY)
-
Ground
—
Continuitv Q-01
17-pins G (BG) Battery Voltage G (BG)
—
Ground Turn ianition
SW ON
12V Q-01
17-pins H (GB) Check connector Continuitv H (GB)
- B
(GB. Q-07)
—
Continuitv
Q-01
17-pins
J (YG) Solenoid valve
Resistance
JfYG)
- K
(Br)

-
Approx.
5.5—7.00
Q-01
17-pins
K (Br) Solenoid valve
Resistance
JfYG)
- K
(Br)

-
Approx.
5.5—7.00
Q-01
17-pins
M (YR) Solenoid valve Resistance M (YR)
- 0
(BW)
-
Approx.
5.5—7.00
Q-01
17-pins
0 (BW) Solenoid valve Resistance M (YR)
- 0
(BW)
-
Approx.
5.5—7.00
Q-01
17-pins
Q (YW) Solenoid valve
Resistance
Q (YW)
- R
(L)

-
Approx.
5.5—7.00
Q-01
17-pins
R (L) Solenoid valve
Resistance
Q (YW)
- R
(L)

-
Approx.
5.5—7.00
Q-01
17-pins
L (B)
Ground circuit Continuity
L (B)
—
Ground
Continuity
Q-01
17-pins
N
(B)
Ground circuit Continuity N (B)
—
Ground Continuity
Q-01
17-pins
P (B)
Ground circuit Continuity
P (B)
—
Ground
C (B.Q-07)
-
Ground
Continuity
4-pins C(B)
Ground circuit Continuity
P (B)
—
Ground
C (B.Q-07)
-
Ground
Continuity

Control Unit Connector View from harness side
Q-01 (11-pin)

LB
GR YG Y W
>1 ,1 U;.l Ki -X
1 L G VL rf
Q-01 (17-pin)
Q-01 ABS Control Unit [R]
YW BW YR Br 8G BL LO WG
icL olL
MIL
ICL G(=L tl ij^" llyl
>1
CjJ
Lt|J JCjJ fiC|3 H«|3
L B B B ffi SB L* GS RY
Check connector (4-pin)
Q-07 Check Connector [RJ
B GR
LY GB
86U11X-199
11—99

13 REAR WHEEL ALIGNMENT
2. Measure the camber angle with the caster/cam-
ber gauge.
Camber: -0°30' ± 45' (2WS)
0°00' ± 45' (4WS)
86U13X-123
Front
EAR TURNING ANGLE (4WS)
Place the rear wheels on a turning radius gauge.
Jack up the front of the vehicle.
Start the engine and let it idle.
Caution
If the engine is stopped while the steering
wheel is left turned to one side or the other,
the rear wheels will return to the straight-
ahead direction, and, when the engine is later
started once again, the direction of the rear
wheels will change. Be sure, therefore, to
check to be sure that the wheels are not
touching, or close to, anyone's hands or feet,
or any other object, when the engine is
stopped or started.
Turn the steering wheel fully left and right, and
measure the rear turning angle.
Rear turning angle Inner 5°00' ± 45'
Outer 5°00' ± 45'
If not within specification, adjust the rear turning
angle. (Refer to Section 10)
86U13X-125
13—54

15 METER

Standard indication
(km/h)
Allowable range
(km/h)

40 40-
43

80 80-
84

120
120—126
Standard indication

(mph)

Allowable range

(mph)
30
30-32

50
50-53

80
80—84

86U15X-029

Standard Indication

(rpm)

Allowable range

(rpm)
1000
850—1090
2000 1910-2210
3000 2850-3330
4000 3820-4420
5000 4790—5510
6000 5760-6600

86U15X-030
INSPECTION OF ANALOG METER
Speedometer
1. Using a speedometer tester, check the speedom-
eter for allowable indication error, and check the
operation of the odometer. Replace if necessary.
2. Check the speedometer for fluctuation and/or ab-
normal noise.
Caution
a) If significant fluctuation occurs or the
speedometer does not move at all, remove
the speedometer cable. If normal, replace
the speedometer assembly.
b)Tire wear and improper inflation will in-
crease speedometer error.
Tachometer
1. Connect a test tachometer to the engine, and start
the engine.
2. Check the tachometer for allowable indicator er-
ror. Replace if necessary.
Caution
When removing or installing the tachometer,
be careful not to drop it.
Fuel Gauge
1. Disconnect the connector from the fuel tank unit.
86U15X-031
Connect the red lead of the SST to the terminal
"Y", and the black lead to a body ground.
86U15X-032
15-26

15 METER

Standard Indication

(rpm)

Allowable range

(rpm)
1000
900—
950

2000 1900-1950
3000 2900—2950
4000 3900-3950
5000 4900—4950
6000 5900-5950

86U15X-037
86U15X-038
86U15X-039
Standard display Expanded display
E ©FUEL F E © FUEL F
"io — •
QJ1QOOODDOOOD
Tachometer
1. Connect a test tachometer to the engine, and start
the engine.
2. Check the tachometer for the allowable indicator
error. Replace digital meter assembly.
Caution
When removing or installing the tachometer,
be careful not to drop it or subject it to sharp
impact.
Fuel Gauge
1. Disconnect the connector from the fuel tank unit.
2. Connect the red lead of the SST to terminal "Y"
and the black lead to body ground.
86U15X-040
Set the SST to the resistance values shown the fol-
lowing table.
Turn the ignition switch ON and check that the seg-
ment displays the correct values in each range.
If the segment displays the correct values, check
the gauge unit. If not, replace the digital meter as-
sembly.
Caution
Continue the above inspections for at least
two minutes each to correctly judge the con-
dition.

Segment Standard display Expanded display Segment Resistance
(Q)
1-10
less than
8
less than
63

1-
9
8-14
63-66

1-
8
14—20 66-70

1-
7
20-25 70-74

1-
6
25-30 74-78

1-
5
30—37 78-82

1-
4
37-46 82-86

1—
3
46-63 86-90

1-
2
63-86 90-93

1
86-98 93-98

1
(flashing) more than
98
less than
98
15-28

15 WARNING AND SENDER
86U15X-068
86U15X069
86U15X-070
Door Switch
1. Check for continuity of the switch with an
ohmmeter.
2. If continuity is not as specified, replace the switch.
Washer Level Sensor
1. Check for continuity between C (LY) terminal and
D (B) terminal of the washer level sensor con-
nector.
Oil Pressure Switch
1. Disconnect the connector from the oil pressure
switch.
2. Check for continuity between the switch and a
body ground with each condition.
Coolant Level Sensor
1. Remove the level sensor and connect the con-
nector.
2. With the sensor not grounded to the body, start
the engine.
3. After checking that the warning light illuminates,
ground the threaded part of the sensor.
4. If the warning light remains illuminated, the sen-
sor is faulty and replace it.
73G15X-013
15—40

Engine Continuity
Running Yes
Stop No
Terminals Float level Continuity
C (LY)—D
(B)
Bottom Yes C (LY)—D
(B)
Above bottom No

2. If continuity is not as specified, replace the sensor.

CRUISE CONTROL SYSTEM 1 5
B.Check Switch
The check switch in the ACC checker is used to
check the actuator operation while the engine is
running. When the check switch is held on after
the engine is started, the engine speed increases
to approximately 2,000 to 3,000 rpm and is main-
tained at that level. When the check switch is
released, the engine speed decreases to idle
speed.
76G15X-073
C.Slide switch
Before using the check switch, first move the slide
switch to the "L" position.
Then use the check switch to increase the engine
rpm.
If the engine rpm stabilizes after increasing to
2,000—3,000 rpm, there is no problem. If there is
no increase at all, or only a slight increase, try again
after setting the slide switch to the "H" position.
If there is still no increase to 2,000—3,000 rpm,
adjust the free play of the actuator inner cable.
76U15X-319
76G15X-074
Preparation
1. ACC checker installation
Depress the lock hook of the harness connector.
Remove the connector from the ACC control unit
after the ignition switch and main switch are turned
off, and then connect the harness connector to the
ACC checker.
2. Checking the free play of the actuator inner
cable
Remove the clip and adjust the nut so that the ac-
tuator control cable play is as follows when the ca-
ble is pressed lightly.
Standard play: 1—3 mm (0.039—0.118 in)
15—85

CRUISE CONTROL SYSTEM 1 5
CHECK LIGHTS (correct response)
ACTUATOR £
5 (O
W X
CHECK ITEMS AND CONDITIONS £ <0 z
VAC
CM I-1-z
Ul * < IE ffl X o V-
z o F < z ta
DC O 1-< DC Ui
TROUBLESHOOTING
(INCORRECT RESPONSE)
< S VAC UJ > < > -1 o o o UJ O
8. START THE ENGINE
• Shift lever to "N" position (A/T) O O O o X
A/T
O M/T X
O or X —
9. ACTUATOR OPERATION: (EGI model only) • After engine is started, set the slide switch "L" or "H". Then turn on check switch (keep in "D" position) Note: Engine speed should in-crease to 2,000—3,000 rpm. If over 4,000 rpm release the switch immediately.
o
X
1
o
X X X
A/T O M/T X
O or X
If engine speed does not come up to and remain
in
the
2,000
to
3,000
rpm. range, check the actuator and as-sociated harness.
10. SPEED SENSOR OUTPUT
Keeping idling condition, drive ve-
hicle slowly. o o 0 o X X 0 1 X
If GENERATOR LIGHT does not flash, trouble may be with speed sensor and associated harness.
76U15X-199
INSPECTION
Actuator
Measure the actuator solenoid resistance by using
an ohmmeter.
Check terminals Resistance
c-d
Approx. 25 to 35 ohms c — a Approx. 25 to 35 ohms
c — b
Approx. 25 to 35 ohms
76G15X-075
Cruise Control Unit
If there is an operation malfunction of the cruise con-
trol system, and no abnormal condition when check-
ing above, replace the cruise control unit and check
system operation.
Clutch Switch, Brake Switch
When removing these switches, turn each of them
so that the corresponding pedal height agrees with
the standard value.
76G15X-076
Brake pedal height: 222 ±1 mm (8.74 1820
Clutch pedal height:
216.5 ±8 mm (8.52 ±820 In)
in)
15-87

1 5 AUTO ADJUSTING SUSPENSION (AAS)
AUTO ADJUSTING SUSPENSION (AAS)
CIRCUIT DIAGRAM
Combination switch iq Speed sensor
M
Panel light
control
AAS control unit
Steering angle sensor
H
N
Check connector
IG IG
Actuator (RR)
-P-Sl
-t-^J
—Pwsl
Actuator (RL)
Actuator (FR) P5fl
+
Actuator (FL)
QO M K GIE C A
ft N J HI F D B
86U15X-151
TROUBLESHOOTING GUIDE
The AAS control unit has a self-diagnosis function detecting the unit itself, electrical parts for AAS sys-
tem, and wiring harness open circuit, to inform mechanics. If it detects their malfunctions, outputs the
output pattern to A (LW) terminal of service connector according to the settled pattern for each mal-
function.
Troubleshooting against AAS system can be conducted by knowing the output pattern (See page 15—96,
97) to detect trouble location. 76gisx-o2o
TROUBLESHOOTING
How To Use Self-Diagnosis System
By using the control unit's self-diagnosis function and
a voltmeter, malfunctions of the system are easily de-
termined. When diagnosing malfunctions, follow the
steps bellow.
1. Connect a voltmeter to A (LW) terminal of the serv-
ice connector in engine room.
2. Read out the output patterns (See page 15—96)
in following condition.
76G15X-079
15—94

OUTLINE 16
TROUBLESHOOTING GUIDE
Problem Probable cause Remedy Reference page
No blower
1. Main fuse (30
A) is
open Replace
operation
2 Malfunction
of
the blower motor Replace 3. Faulty resistor Replace 4. Malfunction
of
the blower switch Replace 5. Open
or
loose connection
in an
electrical circuit Repair 16—6,
7
Insufficient
1. Obstruction
in
the inlet
of
the blower unit Remove the obstruction 16-26
air
2. Clogged evaporator Clean the evaporator
with compressed
air
16-27 3. Frosted evaporator Check the thermostat 16-30 4. Air leakage Check for leakage
at
16-26 both sides
of
the cool-
ing unit

Compressor
1. Malfunction
of
the A/C relay Check operation 16—30
does not run,
2. Malfunction
of
the thermostat Check operation 16—30
or runs
3. Malfunction
of
the refrigerant-pressure switch Check operation 16—31
insufficiently
4.
Air
conditioner fuse (15
A)
failure Replace 5. Compressor drive belt
is
loose Readjust 16—23
6. Internal problem
of
the compressor Repair
or
replace
the
16—13
compressor 7. Battery voltage too low Recharge the battery 8. Layer short
in
the magnet coil Replace 9. Clutch face dirty with
oil
Clean
or
replace the 16-13
clutch 10. Excessive gap between the drive plate and
the
Adjust the gap 16-13
pulley
11. Open circuit
in
the magnet coil Replace 16—13
12 Open circuit Repair 16-6,
7
Refrigeration
Normal pressures are:

pressure is
High pressure
1472—1765 kPa
abnormal (15—18 kg/cm2, 214—255 psi)
Low pressure
197—294 kPa
(2—3 kg/cm2, 29—42 psi)
when: ambient temperature 35°C (95°F)
engine speed 1,500
rpm
Low pressure
1. Internal malfunction
of
the compressor Repair
or
replace the 16-13

is too high
compressor
2. Faulty contact
of
the sensing bulb
of
the expan-Repair 16-26
sion valve 3. Faulty insulation
of
the sensing bulb
of
the expan-Repair 16—26
sion valve
4. Expansion valve open too much Replace 16—26

Low pressure
1. Insufficient refrigerant Charge with refrigerant 16-8

is too low
2. Receiver-drier
is
clogged Replace 16-25
3. Expansion valve
is
clogged Replace 16-26
4. Faulty thermostat Check operation 16-30 5. Frosted piping Clean
or
replace the 16—29
piping

High pres-
1. Poor cooling
of
condenser Check and clean 16-24

sure is too
2. Loose cooling fan drive belt Readjust 16—23

high
3. Too much refrigerant Discharge the excess 16-8
refrigerant 4.
Air in
the system Evacuate and charge 16-8
the system

High pres-
1. Insufficient refrigerant Charge with refrigerant 16-8
sure is too
2. Internal malfunction
of
the compressor Repair
or
replace the 16-13

low
compressor

76G16X-004
16—5