1987 MAZDA 626 sensor

ANTI-LOCK BRAKE SYSTEM (ABS) 1 1
ABS-2
Possible failure
Left front wheel speed sensor, Harness, Hydraulic unit
Disconnect
Q-01
(11-pin)
con-
nector.
Check continuity
at
harness side.
Q-01 (11-pin) Continuity
W (2A) Ground No

OK

Measure side.
Q-01 (11-pin) Resistance
W (2A) R (2B) 800-1200
fl
OK

Connect Q-01 (11-pin) connector. Jump GB
to B
at (Q-07) connector. Start engine.
Check that warning light stays ON. Drive vehicle and check that warn-ing light flashes (0.25 sec ON OFF) at
15
km/h
(9
mph).

NG
Repair harness (Control unit
—
Left front sensor)
resistance
at
harness

NG

Disconnect Q-02 Measure resistance
at
sensor.
Q-02 Resistance
W
| R
800-1200
0
OK

Check followings*
• Clearance between sensor and rotor standard: 0.3—1.1
mm
(0.012-0.043
in)

• Objects sticking
to
sensor
or
rotor • Damaged sensor
or
rotor
• Sensor installation Tightening torque: 16-23 N m
(1.6—2.3 m-kg, 12-17 ft-lb)

NG
OK
NG
Repair
or
replace
as
necessary

NG
Check Q-01 connector,
or
Replace control unit.

OK

Replace hydraulic unit.
Replace left front wheel speed
sensor.
Repair harness.
(Control unit
—
Left front sensor)
"All conditions can
be
verified
as
follows,
if an AC
voltmeter
is
available. 1. Jack
up
vehicle. 2. Measure sensor voltage while rotating left front wheel
one
revolution
per
second.
Q-01 (11-pin) Voltage (AC)
W (2 A)
|
R (2B) More than
0
25V

86U11X-146
11-77

1 1 ANTI-LOCK BRAKE SYSTEM (ABS)
ABS-3
Possible failure
Rear wheel speed sensor, Harness, Hydraulic unit
Disconnect
Q-01
(11-pin)
con-

nector.
Check continuity
at
harness side.
Q-01 (11-pin) Continuity
G (2H) Ground No YG (2E) Ground No
Measure side.
Q-01 (11-pin) Resistance
YG (2E) YL (2F) 800—1200
fi
G (2H)
] L
(2J) 800—1200
fi
OK

Connect Q-01 (11-pin) connector. Jump GB
to B at
Q-07 connector. Start engine.
Check that warning light stays ON. Drive vehicle and check that warn-ing light flashes (0.25 sec ON OFF) at
15
km/h
(9
mph).

NG
Repair harness (Control unit
—
Rear speed sensor)

OK

resistance
at
harness

NG

Disconnect Q-09 and Q-05 Measure resistance
at
sensor.
Q-09, Q-05 Resistance
YG YL 800-1200
0
G L 800-1200
0
OK

Check followings* • Clearance between sensor and rotor standard: 0.3—1.1
mm
(0.012-0.043
in)
• Objects sticking
to
sensor
or
rotor
• Damaged sensor
or
rotor
• Sensor installation Tightening torque: 16-23 N-m
(1.6—2.3 m-kg, 12—17 ft-lb)

NG
Repair
or
replace
as
necessary

NG
Check Q-01 connector. Replace control unit.
or

OK

Replace hydraulic unit,
Replace rear wheel speed
sensor.

OK
Repair harness.
(Control unit
—
Rear speed sensor)
* All conditions can
be
verified
as
follows,
if an AC
voltmeter
is
available. 1. Jack
up
vehicle. 2. Measure sensor voltage while rotating rear wheel
one
revolution
per
second.

fi
wheel Q-01 (11-pin) Voltaqe (AC)
Left |YG (2E) YL (2F) More than 0.25V Right G (2H) L(2J)
More than 0.25V

86U11X-147
11-78

ANTI-LOCK BRAKE SYSTEM (ABS) 1 1
86U11X-1C
Q-08
Q-08
Fail-safe relay
B B BG
(Q-08)(Q-09)

V
BL BR
Motor relay
B BR (Q-09)
LO RY
View from male-pin side
86U11X-167
76G11X-096
ABS WARNING LIGHT
Inspection for No Illumination
1. Check that other warning lights illuminate. If not,
check the METER 10A fuse for burning out.
2. Turn the ignition switch ON.
3. Ground the LY terminal
of
the check connector with
a jumper wire.
4. Check that the ABS warning light illuminates.
If not illuminated, check the bulb and harness (bat-
tery -» check connector).
5. Check for 12V at F (LY) terminal of the control unit
connector.
If the voltage is not as specified, check the harness
(bulb control unit).
If the voltage is as specified, replace the relay box
and the control unit.
RELAY BOX
Inspection of Fail-safe Relay
1. Check for continuity of the relay with an ohmmeter.
Replace the relay box if necessary.
Connecting to BR B (Q-08) B (Q-09) 12V Ground BR B (Q-08) B (Q-09)
— — O— —O
BG BL O— —O
O—O: Indicates continuity
2. Check that the resistance between terminal wire
(BR) and terminal wire (LY) changes when revers-
ing the © and © test-leads. Replace the relay
box if necessary.
Inspection of Motor Relay
1. Check for continuity of the relay with an ohmmeter.
Replace the relay box if necessary.
Connecting to RY B (Q-09) 12V Ground RY B (Q-09)
-—
BR LO o— O
O—O: Indicates continuity
2. Check that the resistance between terminal wire
(BR) and terminal wire (LO) changes when revers-
ing the © and © test-leads. Replace the relay
box if necessary.
WHEEL SPEED SENSOR
Inspection
1. Measure the resistance of the sensor with an
ohmmeter.
Resistance: 800—1,200 0
2. If the resistance is not within specification, replace
the sensor.
3. Check that the harness is not twisted and does not
contact other objects when turning the steering
wheel is turned fully.
11-87

1 1 ANTI-LOCK BRAKE SYSTEM (ABS)
86U11X-170
86U11X-171
Removal of Front Wheel Speed Sensor
1. Remove the wheel and tire.
2. Remove the parts shown in the figure, and remove
the sensor from the knuckle.
Installation of Front Wheel Speed Sensor
1. Install the sensor to the knuckle.
Tightening torque:
16—23 N m (1.6—2.3 m-kg, 12—17 ft-lb)
Caution
The left and right sensors are not interchange-
able. L or R is indicated on the bracket.
2. Install the sensor harness bracket onto the knuckle.
Tightening torque:
16—23 Nm (1.6—2.3 m-kg, 12—17 ft-lb)
3. Push the sensor harness through the splash shield
and secure it with the clip.
4. Install the sensor harness bracket to the body.
Tightening torque:
16—23 Nm (1.6—2.3 m-kg, 12—17 ft-lb)
Caution
Verify that the harness is not twisted and does
not contact the shock absorber or body when
the steering wheel is turned.
5. Connect the sensor connector.
6. Install the wheel and tire.
86U11X-172
11-88

ANTI-LOCK BRAKE SYSTEM (ABS) 1 1
Removal of Rear Wheel Speed Sensor
1. Remove the wheel and tire.
2. Remove the parts shown in the figure, and remove
the sensor from the hub spindle.
86U11X-173
86U11X-174
86U11X-175
Installation of Rear Wheel Speed Sensor
1. Install the sensor to the hub spindle.
Tightening torque:
16—23 N m (1.6—2.3 m-kg, 12—17 ft-lb)
Caution
The left and right sensors are not interchange-
able. L or R is indicated on the bracket.
2. Install the sensor harness bracket onto the knuckle.
Tightening torque:
16—23 Nm (1.6—2.3 m-kg, 12—17 ft-lb)
3. Feed the sensor harness through the body and in-
stall the gromrnet.
4. Install the sensor harness bracket to the body.
Tightening torque:
11—26 N m (1.1—2.6 m-kg, 8—19 ft-lb)
Caution
Verify that the harness is not twisted and does
not contact the shock absorber or body when
the steering wheel is turned.
5. Connect the sensor connector.
6. Install the wheel and tire.
BRAKE LIGHT SWITCH
Refer to page 15—58.
76G11X-060
11-89

1 1 ANTI-LOCK BRAKE SYSTEM (ABS)
SENSOR ROTOR
Inspection
Check the sensor rotor for missing or damaged teeth.
86U11X-177
Removal of Front Sensor Rotor
1. Loosen the front wheel lug nuts.
2. Block the rear wheels.
3. Jack up the front of the vehicle and support it with safety stands.
4. Remove the wheels.
5. Remove in the sequence shown in the figure, referring to removal note for the specially marked parts.
86U11X-178
1. Hub cap
2. Locknut
3. Driveshaft (Refer to section 9)
4. Sensor rotor
11-90

ANTI-LOCK BRAKE SYSTEM (ABS) 1 1
Installation of Front Sensor Rotor
Install in the reverse order of removal, referring
Torque specifications
Removal note
Sensor rotor
Tap the sensor rotor off the drive shaft with a chisel.
to installation note for the specially marked parts.
Installation note
Sensor rotor
Press the sensor rotor onto the driveshaft with the
SST.
Caution
Install the sensor rotor with chamfered edge
toward the driveshaft.
11—91

1 1 ANTI-LOCK BRAKE SYSTEM (ABS)
Removal of Rear Sensor Rotor
1. Loosen the rear wheel lug nuts.
2. Block the front wheels.
3. Jack up the rear of the vehicle and support it with safety stands.
4. Remove the wheels.
5. Remove in the sequence shown in the figure, referring to removal note for the specially marked parts.
86U11X-182
1. Hub cap
2. Locknut
3. Caliper assembly and
mounting support
4. Disc plate
5. Sensor rotor
Removal note
Sensor rotor
Remove the sensor rotor from the hub assembly with
the SST.
86U11X-183
11—92