1987 MAZDA 626 ignition

ELECTRICAL COMPONENTS OF 4-WHEEL STEERING 1 0
TROUBLESHOOTING GUIDE
Self-Diagnosis Function
The four-wheel steering (4WS) control unit contains a self-diagnosis function to detect malfunctions
within itself, the 4WS electrical components and circuits.
If a malfunction is detected, the control unit indicates where the problem is located and the 4WS warn-
ing light in the instrument cluster will flash for one minute with a specific pattern,
Troubleshoot the 4WS system according to the following flow chart.
Symptom of problem
76G10X-026
TROUBLESHOOTING
Checking Condition
Condition A
1. Turn the ignition switch OFF.
2. Start the engine after the ignition switch has been
OFF for at least 10 seconds, and check if the 4WS
warning light flashes or illuminates within 60
seconds.
3.
If
flashing or illumination occurs, inspect the circuit.
(Refer to page 10—95.)
76G10X-027
10—95

1 0 ELECTRICAL COMPONENTS OF 4-WHEEL STEERING
Condition B
1. Place the vehicle on a chassis roller tester. Block
the rear wheels, and secure it with chains.
2. Turn the ignition switch OFF.
3. Start the engine after the ignition switch has been
OFF for at least 10 seconds. Put the transmission
in gear and operate the vehicle at more than 40
km/h (25 mph).
4. Check if the 4WS warning light flashes or il-
luminates within 60 seconds.
5.
If
flashing or illumination occurs, inspect the circuit
by referring to the table below.
76G10X045
Diagnosis Output Pattern
Warning light output pattern
0.5 sec —i 2.5 sec
Malfunction
Normal operation, control unit or wir-ing harness
Speed sensors or
wiring harness
Flow chart
No.
4WS—0
4WS—1
Rear steering gear
assembly
Solenoid valve or wiring harness
Stepper motor or wiring harness
Rear-to-front steer-ing ratio sensor or wiring harness
4WS—2
4WS—3
4WS—4
4WS—5
86U10X-225
10-96

ELECTRICAL COMPONENTS OF 4-WHEEL STEERING 1 0
OK
Replace control unit.
Flashes or
Illuminates
Replace rear steering gear assembly.
4WS-3 Failure of solenoid valve or harness
Disconnect R-01 (17-pin) connector. Check voltage between terminals and body ground with ignition switch ON. OK
Terminal Voltage
E(R) Approx. 12V
F(RY) Approx. 12V

J
NG
Disconnect solenoid valve connector. Check for con-
tinuity between terminals on valve side.
Terminals continuity
GR — RY Yes
GY — R Yes
NG
Replace solenoid valve unit.
Replace control unit.
OK Repair harness (Fuse box to Solenoid valve or Sole-noid valve to Control unit).
76G10X-029
10—99

1 0 ELECTRICAL COMPONENTS OF 4-WHEEL STEERING
flashes
Replace control unit
4WS-9 Failure of control unit, alternator, or wiring harness
Start engine,
I
Check voltage between terminal of control unit con-nector and body ground.
Terminal Voltage
G(B) OV
H (B) OV
K(G) Approx. 12V
L (G) Approx. 12V
N(B) OV
OK
NG
Check 4WS relay and timer (Refer to page 10—103) -
OK
Check battery, harness, and alternator.
NG
Turn ignition switch OFF. Start engine. Check if 4WS warning light flashes or illuminates.
NO
Momentary problem (If warning light often flashes or illuminates, check battery and alter-nator. Replace control unit if necessary).
YES
Replace control unit.
Replace relay and timer
76G10X-031
4WS WARNING LIGHT
1. Turn the ignition switch OFF.
2. Turn the ignition switch ON, and check that the
4WS warning light illuminates.
3. If there is no illumination, check the warning light
bulb and wiring harness.
Replace the control unit if necessary.
86U10X-232
10-102

PARKING BRAKE 1 1
86U11X-130
86U11X-131
PARKING BRAKE
ON-VEHICLE MAINTENANCE
Parking Brake Lever Stroke
Inspection
Check that the stroke is within specification when the
parking brake lever is pulled with a force of 98N
(10kg, 22lb).
Stroke: 5—7 notches
Adjustment
1. Before adjustment, start the engine and depress
the brake pedal several times.
2. Stop the engine.
3. Remove the adjust nut clip and turn the adjust nut
at the front of the parking cable.
4. After adjustment, check the following points:
(1) Turn the ignition switch ON, pull the parking
brake lever one notch, and check that the park-
ing brake warning lamp illuminates.
(2) Check that the rear brakes do not drag.
11—65

PARKING BRAKE 1 1
Inspection Note
Check the following and replace any faulty parts.
1. Sector and ratchet pawl for wear and damage
2. Spring for weakness and breakage
76G11X-090
Installation Note
Parking switch
1. Install the parking switch so that
it
contacts the park-
ing brake lever when the lever is released.
2. Turn the ignition switch ON, and check that the
parking brake warning lamp illuminates with the
lever pulled one notch.
86U11X-135
11—67

ANTI-LOCK BRAKE SYSTEM (ABS) 1 1
TROUBLESHOOTING
Precaution
Conditions that are not malfunctions
1. It may happen that vibration is felt in the steering wheel, body, and/or brake pedal when the ABS
is functioning; such vibration is simply an indication that the system is functioning.
2. Sound of the pump motor operating, accumulator pressure being released, or the relay operating
may be heard from the engine compartment when the engine is started as the system is being auto-
matically checked.
3. The ABS pump motor may be automatically activated even though the ABS is not operating.
4. The ABS warning light may illuminate under any of the following conditions:
• When the vehicle is traveling on snow or ice with the parking brake activated or a brake dragging
at one wheel.
• When different-sized tires are used.
• When tires of different gripping performance are used.
• When (while the vehicle is jacked up or stuck) only the front wheels are spun for 20 seconds or more.
• When there is insufficient battery voltage.
Note
Under the above conditions, the warning light will not illuminate a second time when the
ignition is switched OFF then back ON, and there will be no memory entry to the control
unit of a problem.
Troubleshooting notes
The ABS is composed of electrical components, mechanical components (hydraulic unit), and the com-
ponents of the standard brake system.
Fundamentally, malfunction of the ABS electrical or mechanical components is judged by the self-
diagnosis function within the ABS control unit. And malfunctions are indicated by the warning light
in the instrument panel.
The location
of
a malfunction is indicated by the technician switching the system to the diagnosis-indication
mode.
The self-diagnosis and indication functions must be used when malfunctions of the ABS are being
diagnosed.
76G11X-091
11—73

1 1 ANTI-LOCK BRAKE SYSTEM (ABS)
Troubleshooting Main Flow Chart
Check that the ABS warning light operates.

• Turn ignition switch OFF
to
ON, and check that ABS warning light illuminates constantly.

Flashing (Past failure)
OK
Check the ABS for failure.
• Start engine, and observe flashing
of
warning light.
Does not
illuminate
constantly
Warning light Possible cause
Does
not il-

luminate
at all

Refer
to
page 11—86.

ON
Alternator
L
ter-minal output Wiring harness (ALT-control unit) Control unit

OFF
1 sec

Alternator
L
ter-minal output Wiring harness (ALT-control unit) Control unit

ON
Relay box wiring harness (warning light-control unit) Control unit

OFF
1 sec

Relay box wiring harness (warning light-control unit) Control unit

No illumination
(Not diagnosed)
Illuminates constantly
(Present failure)
ABS is usually operating cor-rectly.
Consult table below when ABS failure
is
still suspected.
System Possible cause
ABS Brake light switch
Both rear wheel speed sensors
Control unit Proportioning
valve
in hy-
draulic unit
Other than Refer
to

ABS troubleshoot-ing guide
on

page 11—5.

Repair failures with flow
chart. (Refer to page
11—76.)
76G11X-054
11-74