Mazda MX-5 Miata (1997+). Manual — part 6

Fig. 10: SRS Wiring Diagram

1997 Mazda MX-5 Miata

AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT Mazda - Air Bag Restraint System

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.

Application

Location

ABS Control Module

Under Carpet, Behind Passenger Seat

Data Link Connector

Left Side Of Engine Compartment

Front Sensor Rotor

On Front Wheel Hub

Hydraulic Unit

Right Rear Of Engine Compartment

Motor & Valve Relays

On Hydraulic Unit

Pump Motor

On Hydraulic Unit

Rear Sensor Rotor

On Rear Drive Axle

Wheel Speed Sensor

On 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

BLEEDING BRAKE SYSTEM

1. Raise and support vehicle. Ensure brake fluid reservoir remains at least half full during bleeding

procedure. When bleeding brake system, start with longest brakeline first. Remove bleed screw cap.
Connect one end of transparent vinyl tube to bleed screw. Submerge other end of tube in a container half
filled with clean brake fluid.

2. Have an assistant depress brake pedal several times and hold in depressed position. Loosen bleed screw

and drain fluid into container. Tighten bleed screw.

3. Refill brake fluid reservoir if necessary. Repeat step 2) until air is no longer discharged. Tighten bleed

screw to 52-78 INCH lbs. (5.9-8.8 N.m). Ensure fluid leakage is not present. Add fluid to reservoir.
Repeat procedure for remaining wheels.

TROUBLE SHOOTING

Before attempting to diagnose vehicle, ensure ABS warning light is functioning properly. ABS warning light
will not illuminate and ABS will not operate if battery voltage is insufficient. Perform trouble shooting
procedures on ABS warning light to eliminate unnecessary repairs and/or component replacement.

ABS WARNING LIGHT DOES NOT ILLUMINATE WHEN IGNITION IS TURNED ON

1. Turn ignition on. Check if other warning lights illuminate. If other warning lights do not illuminate, check

METER fuse. Replace as necessary. If other warning lights illuminate, check for possible malfunction
and repair as necessary. Go to next step.

2. Turn ignition off. Disconnect ABS Control Module (ABS CM) connector. See COMPONENT

LOCATIONS . Turn ignition on. Check if ABS warning light illuminates. If ABS warning light
illuminates, go to next step. If ABS warning light does not illuminate, go to step 5).

3. Reconnect ABS CM connector. Turn ignition on. Check if ABS warning light illuminates. If ABS

warning light does not illuminate, go to next step. If ABS warning light illuminates, a temporary poor
contact in wiring may have occurred and ABS is now functioning properly.

4. Check if terminal AD of ABS CM harness connector is damaged or deformed. See Fig. 3 . If terminal AD

is damaged or deformed, replace wiring harness connector. If terminal AD is okay, replace ABS CM.

5. With ABS CM connector disconnected, use a jumper wire and ground terminal AD of ABS CM harness

connector. Check if ABS warning light illuminates. If ABS warning light illuminates, go to next step. If
ABS warning light does not illuminate, go to step 7).

6. With ABS CM disconnected, check continuity between terminal AB of ABS CM harness connector and

ground. Also, check continuity between terminal AC of ABS CM harness connector and ground, and

CAUTION: DO NOT allow reservoir to run dry during brake bleeding procedure. If

brake fluid is spilled, clean surface immediately with alcohol, as brake
fluid will damage painted surfaces. Use only DOT 3 brake fluid and DO
NOT mix with any other types.

NOTE:

Ensure brake pedal remains depressed until bleed screw is tightened.

1997 Mazda MX-5 Miata

ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock

between terminal AM of ABS CM harness connector and ground. If continuity exists, replace wiring
harness connector. If continuity does not exist, repair wiring harness.

7. Check ABS warning light bulb. Replace bulb as necessary. If bulb is okay, go to next step.

8. Check continuity between terminal AD of ABS CM harness connector and terminal 1K of instrument

cluster connector. See WIRING DIAGRAMS . If continuity exists, check ABS warning light. See ABS
WARNING LIGHT under COMPONENT TESTING . If continuity does not exist, repair wiring
harness.

ABS WARNING LIGHT REMAINS ILLUMINATED

1. Ensure battery is fully charged. Charge or replace as necessary. If battery is fully charged, go to next step.

2. Check ABS Control Module (ABS CM) connector for poor connection. Turn ignition on. Check if ABS

warning light goes out. If ABS warning light does not go out, go to next step. If ABS warning light goes
out, a temporary poor contact in wiring may have occurred and ABS is now functioning properly.

3. Turn ignition off. Disconnect ABS CM connector. See COMPONENT LOCATIONS . 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 harness 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. Connect ABS CM connector. Check for ABS DTCs. See RETRIEVING DIAGNOSTIC TROUBLE

CODES under DIAGNOSIS & TESTING. If no DTCs are present, go to next step.

5. Turn ignition off. Disconnect ABS CM connector. Connect Harness Adapter (49-F066-022). Turn

ignition on. Check if ABS warning light goes out. If ABS warning light does not go out, repair short in
ABS warning light drive harness or instrument cluster. If ABS warning light goes out, replace ABS CM.

ABS WARNING LIGHT FLASHES WITH VEHICLE STOPPED

1. Ensure battery is fully charged. Charge or replace as necessary. If battery is fully charged, go to next step.

2. Check if a jumper wire is installed between terminals TBS and GND of Data Link Connector (DLC). See

Fig. 1 . If jumper wire is installed, remove jumper wire from DLC. If jumper wire is not installed, go to
next step.

3. Turn ignition off. Disconnect ABS Control Module (ABS CM) connector. See COMPONENT

LOCATIONS . Check continuity between terminal "P" of ABS CM harness connector and ground. See
Fig. 3 . If continuity exists, repair short to ground in DLC wiring harness. If continuity does not exist,
replace ABS CM.

NOTE:

ABS warning light will illuminate if voltage between terminal "A" (voltage
supply) of ABS CM harness connector and ground is less than about 10
volts.

1997 Mazda MX-5 Miata

ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock