1997 MAZDA MX-5 light

3. Turn ignition off. Disconnect ABS CM connector. Measure voltage between terminals "A" and AB of
ABS CM harness connector. See Fig. 3
. Also, measure voltage between terminals "A" and AC of ABS
CM ha rness connector, and between terminals "A" and AM of ABS CM harness connector. If battery
voltage is present, go to next step. If battery voltage is not present, repair wiring harness.
4. Turn ignition off. Reconnect ABS CM connector. Drive vehicle and recheck ABS warning light. If ABS
warning light illuminates/goes out with vehicle stopped and during driving, replace ABS CM. If ABS
warning light does not illuminate/go out with vehicle stopped and during driving, a temporary poor
contact in wiring may have occurred and ABS is now functioning properly.
ABS WARNING LIGHT INDICATES NORMAL, BUT ABS DOES NOT OPERATE PROPERLY
Check for ABS DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES
under DIAGNOSIS &
TESTING. If no DTCs are present, inspect mechanical system.
PRE-DIAGNOSIS INSPECTION
Visually inspect ABS components for possible cause of anti-lock problem. Visual inspection may help identify
cause of a simple malfunction. Ensure ABS warning light is functioning properly. See TROUBLE
SHOOTING .
ABS warning light illuminates under the following conditions:
Vehicle operated on snow or ice with parking brake activated, or a dragging brake at one wheel.
Different size tires being used.
Tires with different traction characteristics are used on same axle.
Vehicle is jacked up and drive wheels spin for 20 seconds or more with ignition on.
Low battery voltage.
If ABS warning light illuminates because of these conditions, turn ignition off, then back on. ABS warning light
will go out and no DTCs for described conditions will be stored in ABS control module memory.
DIAGNOSIS & TESTING
Diagnose ABS using New Generation Star (NGS) Tool (49-T088-0A0) and Adapter Harness (49-F066-002).
See RETRIEVING DIAGNOSTIC TROUBLE CODES
. On all models, test ABS control module using
DVOM and adapter harness. See ABS CONTROL MODULE under COMPONENT TESTING
.
If ABS test equipment is unavailable, test each component of ABS. See COMPONENT TESTING
. If all
ABS components test okay, replace ABS control module with a known-good module and retest system.
RETRIEVING DIAGNOSTIC TROUBLE CODES
Using New Generation Star (NGS) Tool
1. Turn ignition off. Connect New Generation Star (NGS) Tool (49-T088-0A0) to Data Link Connector

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(DLC). Set NGS Adapter (49-T088-003) to ABS. Select VEHICLE & ENGINE SELECTION, then select
vehicle model, engine type and model year. Select DIAGNOSTIC DATA LINK. Select ABS-ANTI
LOCK BRAKE MODULE.
2. Select DIAGNOSTIC TEST MODE and note any codes displayed. See DIAGNOSTIC TROUBLE
CODE DESCRIPTION table. Perform appropriate test. See DIAGNOSTIC TROUBLE CODE (DTC)
TESTING . Clear codes after servicing. See CLEARING CODES .
DIAGNOSTIC TROUBLE CODE DESCRIPTION
DTCProbable Cause
05 Stoplight Switch Wiring Harness
11 Right Front Wheel Speed Sensor/Sensor Rotor
12 Left Front Wheel Speed Sensor/Sensor Rotor
13 Right Rear Wheel Speed Sensor/Sensor Rotor
14 Left Rear Wheel Speed Sensor/Sensor Rotor
15 Wheel Speed Sensor/Sensor Rotor
22 (1) Right Front Solenoid Valve (AV)
23 (2) Right Front Solenoid Valve (EV)
24 (1) Left Front Solenoid Valve (AV)
25 (2) Left Front Solenoid Valve (EV)
26 (1) Rear Solenoid Valve (AV)
27 (2) Rear Solenoid Valve (EV)
51 Valve Relay
53 Motor Relay/Pump Motor
61 ABS Control Module
(1)Pressure retention valve.
(2)Pressure reduction valve.

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Fig. 2: Reading Diagnostic Trouble Code Output
Courtesy of MAZDA MOTORS CORP.
CLEARING CODES
1. Turn ignition off. Connect a jumper wire between TBS terminal and GND terminal of Data Link
Connector (DLC). See Fig. 1
. Turn ignition on. Output all diagnostic trouble codes stored in ABS control
module memory. When first code is repeated, depress brake pedal 10 times at intervals of less than one
second.
2. When codes are cleared, ABS warning light will illuminate for 3 seconds, then go out. ABS operation
should return to normal control. If ABS warning light does not operate as described and ABS does not
return to normal operation, repeat procedure ensuring brake pedal interval does not exceed one second.
DIAGNOSTIC TROUBLE CODE (DTC) TESTING
* PLEASE READ FIRST *
NOTE: Disconnecting battery does not clear Diagnostic Trouble Codes (DTCs). If DTCs
will not clear, ensure stoplight switch is functioning properly.
NOTE: See PRE
-DIAGNOSIS INSPECTION and DIAGNOSIS & TESTING before
proceeding with DIAGNOSTIC TROUBLE CODE (DTC) TESTING. After repairs
are complete, clear DTCs from ABS control module memory. See CLEARING
CODES under DIAGNOSIS & TESTING.

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DTC 05: STOPLIGHT SWITCH WIRING HARNESS
1. Check stoplight switch wiring harness for open or short to ground between stoplight switch and ABS
control module. See WIRING DIAGRAMS
. Repair as necessary. If wiring harness is okay, go to next
step.
2. Clear DTCs. See CLEARING CODES under DIAGNOSIS & TESTING. Recheck for DTCs. If DTC 05
is displayed, replace ABS control module. If DTC 05 is not displayed, a temporary poor contact in wiring
may have occurred and ABS is now functioning properly.
DTCS 11, 12, 13 & 14: WHEEL SPEED SENSOR, SENSOR ROTOR, HYDRAULIC UNIT OR
WIRING HARNESS
1. Check ABS control module connector for poor connection. See COMPONENT LOCATIONS
. Repair
as necessary. If connector is okay, go to next step.
2. Check wiring harness for open or short to ground between suspect wheel speed sensor and ABS control
module. See WIRING DIAGRAMS
. Repair as necessary. If wiring harness is okay, go to next step.
3. Check suspect wheel speed sensor. See WHEEL SPEED SENSORS under COMPONENT TESTING
.
Replace as necessary. If wheel speed sensor is okay, go to next step.
4. Inspect wheel speed sensor rotor for damage or missing teeth. If sensor rotor is damaged or has missing
teeth, replace sensor rotor. If sensor rotor is okay, go to next step.
5. Inspect brakeline for damage. If brakeline is damaged, replace brakeline. If brakeline is okay, go to next
step.
6. Check hydraulic unit. See HYDRAULIC UNIT under COMPONENT TESTING
. Replace as
necessary. If hydraulic unit is okay, go to next step.
7. Clear DTCs. See CLEARING CODES
under DIAGNOSIS & TESTING. Recheck for DTCs after
driving vehicle from a stop to faster than 6.2 MPH. If DTC 11, 12, 13 or 14 is displayed, replace ABS
control module. If DTC 11, 12, 13 or 14 is not displayed, a temporary poor contact in wiring may have
occurred and ABS is now functioning properly.
DTC 15: WHEEL SPEED SENSOR, SENSOR ROTOR, HYDRAULIC UNIT OR WIRING HARNESS
If DTC 15 is displayed, perform DTCS 11
, 12, 13 & 14: WHEEL SPEED SENSOR, SENSOR ROTOR,
HYDRAULIC UNIT OR WIRING HARNESS test.
DTCS 22, 23, 24, 25, 26 & 27: SOLENOID VALVE OR WIRING HARNESS
1. Check ABS control module connector for poor connection. See COMPONENT LOCATIONS
. Repair
as necessary. If connection is okay, go to next step.
2. Check suspect solenoid valve with valve relay installed. See SOLENOID VALVES
under
COMPONENT TESTING. Replace as necessary. If solenoid valve with valve relay installed is okay, go
to next step.
3. Check suspect solenoid valve with valve relay removed. See SOLENOID VALVES
under
COMPONENT TESTING. Replace solenoid valve as necessary. If solenoid valve with valve relay
removed is oka
y, go to next step.

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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.)

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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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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.

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Fig. 15 .
3. Lightly push on end of adjusting gauge rod to ensure it is properly seated. Verify no gap exists between
adjusting nut and adjusting gauge body. Remove adjusting gauge from power brake unit without
disturbing adjusting nut. Place adjusting gauge on master cylinder.
4. Lightly push on end of adjusting gauge rod to ensure gauge rod is bottomed in master cylinder piston.
Ensure no clearance exists between adjusting gauge body and adjusting nut (clearance "B") or between
body and master cylinder (clearance "C"). Perform STEP 2. See Fig. 15
.
5. If clearance "B" exists, push rod is too short. If clearance "C" exists, push rod is too long. To adjust
clearance "B", go to next step. To adjust clearance "C", go to step 8).
6. To adjust clearance "B", lightly push on end of adjusting gauge rod. Using a feeler gauge, measure
clearance between adjusting nut and adjusting gauge. Perform STEP 3. See Fig. 15
.
7. Using Push Rod Adjuster (49-B043-004) and Adapter (49-B043-003), turn push rod nut to lengthen
power brake booster push rod an amount equal to amount measured at clearance "B" in step 6). Perform
STEP 4. See Fig. 15
.
8. To adjust clearance "C", measure and record adjusting gauge rod height D1. Perfrom STEP 5. See Fig.
15 . Turn adjusting nut until adjusting gauge body sits squarely on master cylinder.
9. Turn adjusting nut only enough for body to touch adjusting gauge. Measure and record adjusting gauge
height D2 of adjusting gauge rod. Perform STEP 6. See Fig. 15
. Subtract D1 from D2 measurement.
10. Using push rod adjuster and adapter, turn push rod nut to shorten power brake booster push rod an
amount equal to difference between hei
ght D1 and D2. Perform STEP 4. See Fig. 15 . NOTE: When lightly pushing on end of adjusting gauge rod in step 4), only use
enough pressure to bottom rod in piston. Too much pressure may cause a
false reading.
NOTE: Push rod threads are specially designed so bolt becomes harder to turn
past a certain point to prevent loosening of bolt. Turn bolt only within this
range.

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