1997 MAZDA MX-5 brake

4. Check wiring harness for open or short to ground between hydraulic unit and ABS control module. See
WIRING DIAGRAMS
. Repair as necessary. If wiring harness is okay, go to next step.
5. Clear DTCs. See CLEARING CODES
under DIAGNOSIS & TESTING. Recheck for DTCs. If DTC
22, 23, 24, 25, 26 or 27 is displayed, replace ABS control module. If DTC 22, 23, 24, 25, 26 or 27 is not
displayed, a temporary poor contact in wiring may have occurred and ABS is now functioning properly.
DTC 51: VALVE RELAY OR WIRING HARNESS
1. Check BTN fuse. Replace as necessary. If BTN or ABS fuse is okay, go to next step.
2. Check valve relay. See VALVE RELAY
under COMPONENT TESTING. Replace as necessary. If
valve relay is okay, check wiring harness for open or short to ground between valve relay and ABS
control module. See WIRING DIAGRAMS
. Repair as necessary. If wiring harness is okay, go to next
step.
3. Clear DTCs. See CLEARING CODES
under DIAGNOSIS & TESTING. Recheck for DTCs. If DTC 51
is displayed, replace ABS control module. If DTC 51 is not displayed, a temporary poor contact in wiring
may have occurred and ABS is now functioning properly.
DTC 53: PUMP MOTOR, MOTOR RELAY OR WIRING HARNESS
1. Turn ignition off and check if pump motor continues to operate. If pump motor continues operating after
ignition is off, replace motor relay. If pump motor does not continue to operate after ignition is off, go to
next step.
2. Check ABS fuse. Replace as necessary. If ABS fuse is okay, go to next step.
3. Check motor relay. See MOTOR RELAY
under COMPONENT TESTING. Replace as necessary. If
motor relay is okay, check wiring harness for open or short to ground between motor relay and ABS
control module. See WIRING DIAGRAMS
. Repair as necessary. If wiring harness is okay, go to next
step.
4. Check pump motor. See PUMP MOTOR
under COMPONENT TESTING. Replace as necessary. If
pump motor is okay, check wiring harness for open or short to ground between hydraulic unit and ABS
control module. Repair as necessary. If wiring harness is okay, go to next step.
5. Clear DTCs. See CLEARING CODES
under DIAGNOSIS & TESTING. Recheck for DTCs. If DTC 53
is displayed, replace ABS control module. If DTC 53 is not displayed, a temporary poor contact in wiring
may have occurred and ABS is now functioning properly.
DTC 61: ABS CONTROL MODULE
1. Check ABS control module connector for poor connection. See COMPONENT LOCATIONS
. Repair
as necessary. If connector is okay, go to next step.
2. Clear DTCs. See CLEARING CODES under DIAGNOSIS & TESTING. Recheck for DTCs. If DTC 61
is displayed, replace ABS control module. If DTC 61 is not displayed, a temporary poor contact in wiring
may have occurred and ABS is now functioning properly.
COMPONENT TESTING

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ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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GENERAL NOTE
ABS CONTROL MODULE
Turn ignition off. Test ABS Control Module (ABS CM) using DVOM and Adapter Harness (49-F066-002)
connected to ABS CM connector. See Fig. 3
. Measure resistance, continuity or voltage as specified. See Fig. 3
-7. If checking voltage, measure between applicable terminal and GND terminal (AB, AC or AM) of ABS CM
connector. If voltage, continuity or resistance is not as specified, replace ABS CM.
Fig. 3: Identifying ABS Control Module Connector Terminals

Courtesy of MAZDA MOTORS CORP.
Fig. 4: Testing ABS Control Module (1 Of 3)

Courtesy of MAZDA MOTORS CORP. NOTE: Before testing ABS components, ensure battery and charging system are
functioning properly.

1997 Mazda MX-5 Miata
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Fig. 5: Testing ABS Control Module (2 Of 3)
Courtesy of MAZDA MOTORS CORP.

1997 Mazda MX-5 Miata
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Fig. 6: Testing ABS Control Module (3 Of 3)
Courtesy of MAZDA MOTORS CORP.
HYDRAULIC UNIT
On-Vehicle Inspection
1. Ensure all diagnostic trouble codes have been cleared and battery is fully charged. See CLEARING
CODES under DIAGNOSIS & TESTING. Turn ignition on and check if ABS warning light goes out
after 2-4 seconds. If ABS warning light remains illuminated, ABS control module has detected a failure
and will not activate hydraulic unit. See DIAGNOSIS & TESTING
.
2. Turn ignition off. Ensure vehicle is on level surface. Raise and support vehicle. Place transmission in
Neutral. Release parking brake. Rotate wheels by hand and check for brake drag. Connect a jumper wire
between TBS terminal and GND terminal of data link connector. See Fig. 1
. Depress brake pedal and
have an assistant attempt to rotate right front wheel. Wheel should not rotate.
3. With brake pedal still depressed, turn ignition on. Brake should be momentarily released (about .5
second) and wheel should turn when pressure reduction operates. Check operation of remaining wheels
using same procedure beginning with left front, right rear, then left rear wheels.
4. If all wheels operate as specified, the following systems are operating properly.
Brake piping to hydraulic unit.
Braking system, including hydraulic unit.
Hydraulic unit electrical system (solenoid, pump motor, etc.)

1997 Mazda MX-5 Miata
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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

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Fig. 8: Identifying Hydraulic Unit Connector Terminals
Courtesy of MAZDA MOTORS CORP.

1997 Mazda MX-5 Miata
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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.

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