1997 MAZDA MX-5 engine

ANTI-LOCK BRAKE SYSTEM
1997 BRAKES Mazda - Anti-Lock
DESCRIPTION
The Anti-Lock Brake System (ABS) control module senses reductions in front and rear wheel speed and
modulates hydraulic pressure to the brakes to prevent wheel lock-up. The ABS consists of a hydraulic unit, 4
wheel speed sensors and sensor rotors, valve relay, motor relay, pump motor and ABS control module. An ABS
warning light is located on the instrument cluster.
OPERATION
Under normal driving conditions, Anti-Lock Brake System (ABS) functions like a standard brake system. When
vehicle speed reaches 3.8 MPH, ABS will diagnose pump motor by briefly operating motor. Pump motor
operation may be heard inside vehicle.
ABS control module controls ABS by detecting speed sensor signals and activating solenoid valve in hydraulic
unit. Control module also controls pump motor and self-diagnostic function. If a problem is detected in ABS,
ABS will function like a conventional brake system. ABS warning light will also come on.
With detection of wheel lock-up, short pedal pulsations, occurring in rapid succession, will be felt in brake
pedal and steering wheel. Vehicle body may also vibrate slightly. These conditions are normal. Pedal pulsation
will continue until there is no longer a need for anti-lock function or until vehicle is stopped.
COMPONENT LOCATIONS
COMPONENT LOCATIONS CAUTION: See ANTI
-LOCK BRAKE SAFETY PRECAUTIONS article in GENERAL
INFORMATION.
NOTE: For more information on brake system, see BRAKE SYSTEM article.
ApplicationLocation
ABS Control ModuleUnder Carpet, Behind Passenger Seat
Data Link ConnectorLeft Side Of Engine Compartment
Front Sensor RotorOn Front Wheel Hub
Hydraulic UnitRight Rear Of Engine Compartment
Motor & Valve RelaysOn Hydraulic Unit
Pump MotorOn Hydraulic Unit
Rear Sensor RotorOn Rear Drive Axle
Wheel Speed SensorOn Knuckle

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

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

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. 15: Adjusting Master Cylinder Push Rod
Courtesy of MAZDA MOTORS CORP.
BRAKE PEDAL HEIGHT & STOPLIGHT SWITCH
1. Released pedal height is measured from carpet surface, on vertical portion of firewall, to pedal pad center.
Disconnect stoplight switch electrical connector. Loosen lock nut on stoplight switch. Rotate switch away
from pedal. Loosen push rod lock nut. Rotate push rod until correct pedal height is as specified. See
BRAKE PEDAL HEIGHT SPECIFICATIONS
table.
2. Adjust pedal free play. See BRAKE PEDAL FREE PLAY
under ADJUSTMENTS. Tighten push rod
lock nut. Tighten push rod lock nut to 18-25 ft. lbs. (24-34 N.m).
3. Rotate stoplight switch until it contacts pedal, then rotate an additional 1/2 turn. Tighten stoplight switch
lock nut to 10-13 ft. lbs. (14-18 N.m). Reconnect stoplight switch electrical connector.
4. Applied pedal height is measured from angled portion of firewall (without carpet) to pedal pad center.
Start engine. Depress brake pedal with a pressure of 132 lbs. (60 kg).
5. Measure applied pedal height. See BRAKE PEDAL HEIGHT SPECIFICATIONS
table. If distance is
not as specified, check for air in system or worn pads. Repair as necessary.
BRAKE PEDAL HEIGHT SPECIFICATIONS
BRAKE PEDAL FREE PLAY
ApplicationIn. (mm)
Pedal Released6.8-7.1 (171-181)
Pedal Applied (1) 3.7 (95)
(1)Minimum height.

1997 Mazda MX-5 Miata
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With engine off, depress pedal a few times to eliminate vacuum. Depress brake pedal by hand and check pedal
free play. See BRAKE PEDAL FREE PLAY SPECIFICATIONS
table. Adjust play by loosening push rod
lock nut. Turn push rod until correct free play is obtained. Tighten push rod lock nut to 18-25 ft. lbs. (24-34
N.m).
BRAKE PEDAL FREE PLAY SPECIFICATIONS
PARKING/EMERGENCY BRAKE
1. Depress brake pedal several times. Pull parking brake lever with a force of 44 lbs. (20 kg). If stroke is 7-9
notches, parking brake is properly adjusted. If stroke is not 7-9 notches, raise and support rear of vehicle.
Release parking brake lever.
2. Rotate cable adjusting nut at lever end of cable, located under console cover, until stroke is within
specification. Ensure rear brakes do not drag. Ensure parking brake warning light illuminates when brake
lever is pulled one notch.
TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS
WIRING DIAGRAMS
ApplicationIn. (mm)
Miata.16-.28 (4-7)
ApplicationFt. Lbs. (N.m)
Brake Caliper Mounting Bolts37-50 (50-68)
Brakeline Nuts10-16 (14-22)
Hydraulic Unit Brakeline Union Bolts18-26 (24-35)
Hydraulic Unit Mounting Bolts/Nuts14-18 (19-24)
I-Arm-To-Rear Steering Knuckle Bolt (RX7)44-54 (59-73)
Lower Control Arm-To-Rear Steering Knuckle Nut47-54 (64-73)
Push Rod Lock Nut18-25 (24-34)
Stoplight Switch Lock Nut10-13 (14-18)
Wheel Bearing Lock Nut
Front123-159 (167-216)
Rear159-217 (216-294)
Wheel Lug Nuts66-86 (89-117)
Wheel Speed Sensor Mounting Bolt12-16 (16-22)
INCH Lbs. (N.m)
ABS Control Unit Mounting Bolts/Nuts61-87 (6.9-9.8)

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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1997 AUTOMATIC TRANSMISSIONS
NC4A-EL Electronic Controls
APPLICATION
TRANSMISSION APPLICATION
DESCRIPTION
The NC4A-EL series is a 4-speed electronically controlled automatic transmission. Five solenoids attached to
valve body control shift changes. Solenoids are controlled by the Transmission Control Module (TCM).
The TCM receives information from various input devices. The TCM uses this information to control following
solenoids:
Shift solenoids for transmission shifting.
Torque Converter Clutch (TCC) solenoid for torque converter clutch lock-up.
3-2 control solenoid for downshift timing control.
A HOLD switch is mounted on the shift lever. HOLD function may be activated in "D", "S" or "L" gears by
pressing HOLD button. In "L" and "S" positions, vehicle is held in selected gear and no upshift or downshift
takes place. This function is used for driving up steep inclines or for engine braking assistance when descending
steep grades. If activated in "D" position a 1-2 and 2-3 upshift is permitted when starting from a stop, but after
the 2-3 upshift the vehicle is locked in "D" until it comes to a complete stop. The 1-2 and 2-3 upshift pattern is
changed to a "short shift" specification. This function is used for starting off or driving on slippery surfaces.
Pushin
g HOLD button again deactivates system.
VehicleTransmission Model
MiataNC4A-EL
CAUTION: Vehicle is equipped with Supplemental Restraint System (SRS). When
servicing vehicle, use care to avoid accidental air bag deployment. SRS-
related components are located in steering column, center console and
instrument panel. DO NOT use electrical test equipment on these circuits.
If necessary, deactivate SRS before servicing components. See AIR BAG
DEACTIVATION PROCEDURES article in GENERAL INFORMATION.
CAUTION: Disconnecting battery on models equipped with anti-theft radio require
canceling of anti-theft operation. See appropriate AUTOMATIC
TRANSMISSION SERVICING article in TRANSMISSION SERVICING. Refer
to vehicle owner's manual to identify radio type.
NOTE: Torque Converter Clutch (TCC) solenoid is also known as lock-up solenoid,
TCC lock-up or 4th gear solenoid.

1997 Mazda MX-5 Miata
1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls

1997 Mazda MX-5 Miata
1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls
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Fig. 1: Locating Solenoid Valves
Courtesy of MAZDA MOTORS CORP.
SELF-DIAGNOSTIC SYSTEM
SYSTEM DIAGNOSIS
TCM monitors transmission operation and contains a self-diagnostic system which stores a Diagnostic Trouble
Code (DTC) if an electronic control system failure or component malfunction exists. If a problem exists in any
of the solenoids or speed sensors and DTC is set, TCM will deliver a signal to blink the HOLD indicator light
on instrument panel to warn the driver. DTC may be set if a failure exists and can be retrieved for transmission
diagnosis.
RETRIEVING TROUBLE CODES
NOTE: Before testing transmission, ensure fluid level is correct. Ensure engine starts
with shift lever in Park and Neutral to ensure proper adjustment of transmission
range switch. Transmission Control Module (TCM) must first be checked for
stored codes. See RETRIEVING TROUBLE CODES
.
NOTE: Before retrieving DTC, ensure proper battery voltage exists for self-diagnostic
system operation. If any DTC are present other than those listed below, see

1997 Mazda MX-5 Miata
1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls
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Using Scan Tool
Ensure ignition is in OFF position. Connect scan tool to Data Link Connector (DLC) located under left side of
instrument panel, near center console. Turn ignition switch to ON position. Check for stored DTC. See
DIAGNOSTIC TROUBLE CODE IDENTIFICATION
table. For trouble shooting of codes, see
DIAGNOSTIC TESTS
. appropriate SELF-DIAGNOSTIC SYSTEM article in ENGINE PERFORMANCE.

1997 Mazda MX-5 Miata
1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls
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