1997 MAZDA MX-5 lock

ABS control module output system (solenoid, relay, etc.) and harness.
5. If all wheels do not operate as specified, check ABS control module input system and wiring harness for
intermittent failure. Check for fluid leakage. Repair as necessary. If input system, wiring harness,
intermittent failure or fluid leakage are not present, replace hydraulic unit.
PUMP MOTOR
1. Turn ignition off. Disconnect ABS Control Module (ABS CM) connector. See COMPONENT
LOCATIONS . Connect Adapter Harness (49-F066-002) to ABS CM connector. Using ohmmeter,
measure resistance between terminal "X" of ABS CM connector and ground. See Fig. 3
. Resistance
should not be more than one ohm. If the resistance is not as specified, check wiring harness between ABS
CM and pump motor. Refer to WIRING DIAGRAMS
. If wiring harness is okay, go to next step.
2. Turn ignition off. Disconnect pump motor/hydraulic unit 2-pin connector. Using ohmmeter, measure
resistance between terminal "B" of pump motor/hydraulic unit connector and ground. See Fig. 7
.
Resistance should not be more than one ohm. Apply 12 volts across pump motor/hydraulic unit 2-pin
connector terminals. Pump motor should operate. If resistance is not as specified or pump motor does not
operate, check wiring harness. If wiring harness is okay, replace hydraulic unit.
Fig. 7: Identifying Pump Motor/Hydraulic Unit Connector Terminals

Courtesy of MAZDA MOTORS CORP.
SOLENOID VALVES
With Valve Relay Installed
Turn ignition off. Disconnect hydraulic unit 12-pin connector. See COMPONENT LOCATIONS. Apply 12

1997 Mazda MX-5 Miata
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volts to terminal "A" and ground terminal "D" of hydraulic unit 12-pin connector. See Fig. 8 . Using ohmmeter,
measure resistance between terminal "B" and specified terminals of hydraulic unit connector. See
HYDRAULIC UNIT CONNECTOR TERMINAL RESISTANCE
table. If resistance is not as specified,
check solenoid valves with vale relay removed. See WITH VALVE RELAY REMOVED. Also check valve
relay. See VALVE RELAY.
HYDRAULIC UNIT CONNECTOR TERMINAL RESISTANCE
With Valve Relay Removed
Turn ignition off. Remove hydraulic unit. See HYDRAULIC UNIT under REMOVAL & INSTALLATION .
Remove valve relay from hydraulic unit. Using ohmmeter, measure resistance between terminal "X" of
hydraulic unit valve relay connector and specified terminals of hydraulic unit connector. See Fig. 8
and Fig. 9 .
See HYDRAULIC UNIT CONNECTOR TERMINAL RESISTANCE
table. If resistance is not as specified,
check wirin
g harness. If wiring harness is okay, replace hydraulic unit.
TerminalOhms
"H"4.7
"I"4.7
"J"4.7
"M"9
"N"9
"O"9

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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Fig. 8: Identifying Hydraulic Unit Connector Terminals
Courtesy of MAZDA MOTORS CORP.

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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Fig. 9: Locating Hydraulic Unit Valve Relay Connector Terminals
Courtesy of MAZDA MOTORS CORP.
ABS WARNING LIGHT
Operational Test
1. Start engine and observe ABS warning light. Light should illuminate for a few seconds. If light does not
illuminate as described, turn ignition off. Disconnect ABS control module connector. Using a jumper
wire, connect terminal AD of ABS control module connector to ground. See Fig. 3
. Turn ignition on.
2. If ABS warning light illuminates, check ABS control module. See ABS CONTROL MODULE. If light
does not illuminate, remove instrument cluster. Remove and check ABS warning light bulb. Replace bulb
as necessary. If bulb is okay, check METER fuse and wiring harness. Repair or replace as necessary. If
METER fuse and wiring harness are okay, go to next step.
3. Using ohmmeter, connect positive lead to terminal 2K (Black/Yellow wire) of instrument cluster and
negative lead to terminal 1K (Blue/Yellow wire) of instrument cluster. See Fig. 10
. If continuity is not
present, replace instrument cluster. If continuity is present, repair wiring harness between instrument
cluster and ABS control module.

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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Fig. 10: Identifying Instrument Cluster Connector Terminals
Courtesy of MAZDA MOTORS CORP.
STOPLIGHT SWITCH
Disconnect stoplight switch connector. Using ohmmeter, check continuity between stoplight switch terminals.
With brake pedal depressed, continuity should exist. With brake pedal released, continuity should not exist. If
continuity is not as specified, replace stoplight switch.
MOTOR RELAY
1. Turn ignition off. Disconnect ABS Control Module (ABS CM) connector. See COMPONENT
LOCATIONS . Connect Adapter Harness (49-F066-002) to ABS CM connector. Turn ignition on. Using
voltmeter, measure voltage between terminals "X" and AB of ABS CM connector. See Fig. 3
. Voltage
should be zero volts. Apply 12 volts to terminal "B" an d ground terminal "G" of ABS CM connector.
Using voltmeter, measure voltage between terminals "X" and AB of ABS CM connector. Voltage should
be 12 volts. If voltage is not as specified, check wiring harness. If wiring harness is okay, go to next step.
2. Remove motor relay from hydraulic unit. See Fig. 14
. Using ohmmeter, check continuity between
terminals "B" and "C" of motor relay. See Fig. 11
. Continuity should exist. Apply 12 volts to terminal
"C" and ground terminal "B". Using ohmmeter, check continuity between terminals "A" and "D" of motor
rela
y. Continuity should exist. If continuity is not as specified, replace motor relay.

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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Fig. 11: Identifying Motor Relay Terminals
Courtesy of MAZDA MOTORS CORP.
VALVE RELAY
1. Turn ignition off. Disconnect ABS Control Module (ABS CM) connector. See COMPONENT
LOCATIONS . Connect Adapter Harness (49-F066-002) to ABS CM connector. Turn ignition on. Using
voltmeter, measure voltage between terminal AB and terminals "E", "Z", "Y", AG, BA and BB of ABS
CM connector. See Fig. 3
. Voltage on all terminals should be zero volts. If voltage is as specified, go to
next step. If voltage is not as specified, check wiring harness and repair as necessary. If wiring harness is
okay, go to step 3).
2. Apply 12 volts to terminal "B" and ground terminal AK of ABS CM connector. Using voltmeter, measure
voltage between terminal AB and terminals "E", "Z", "Y", AG, BA and BB of ABS CM connector. See
Fig. 3
. Voltage on all terminals should be 12 volts. If voltage is not as specified, check wiring harness. If
wiring harness is okay, go to next step.
3. Remove valve relay from hydraulic unit. See Fig. 14
. Using ohmmeter, check continuity between
terminals "B" and "C" of valve relay. See Fig. 12
. Continuity should exist. Apply 12 volts to terminal
"B" and ground terminal "C". Using ohmmeter, check continuity between terminals "A" and "D" of valve
rela
y. Continuity should exist. If continuity is not as specified, replace valve relay.

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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Fig. 12: Identifying Valve Relay Terminals
Courtesy of MAZDA MOTORS CORP.
WHEEL SPEED SENSORS
On-Vehicle Inspection
Remove wheel. Inspect wheel speed sensor for looseness and damage. Replace as necessary. Measure clearance
between wheel speed sensor and sensor rotor. See Fig. 13
. Clearance should be .012-.043" (.3-1.1 mm). If
clearance is not as specified, replace wheel speed sensor or sensor rotor.
Resistance Test
Disconnect wheel speed sensor connector. Using ohmmeter, measure resistance between wheel speed sensor
terminals. Resistance should be 800-1200 ohms. If resistance is not as specified, replace wheel speed sensor.
Voltage Test
Ensure vehicle is on level surface. Raise and support vehicle on safety stands. Disconnect wheel speed sensor
connector. Using voltmeter, while rotating wheel one revolution per second, measure voltage between wheel
speed sensor terminals. Voltage should be .25-1.2 volts (AC). If voltage is not as specified, replace wheel speed

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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Sunday, July 05, 2009 1:48:49 PMPage 19 © 2005 Mitchell Repair Information Company, LLC.

sensor or sensor rotor.
Fig. 13: Measuring Wheel Speed Sensor Clearance

Courtesy of MAZDA MOTORS CORP.
WHEEL SPEED SENSOR ROTORS
Inspection
Perform a comprehensive visual inspection of wheel speed sensor rotor. If any teeth are damaged or missing, or
any other damage is noted, replace wheel speed sensor rotor.
REMOVAL & INSTALLATION
ABS CONTROL MODULE
Removal & Installation
1. Disconnect negative battery cable. Roll back carpet from passenger-side footwell. Remove ABS control
module protector panel (if equipped).

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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