brake sensor MAZDA MX-5 1994 Owner's Manual

ANTILOCK BRAKE SYSTEM (ABS) P ANTILOCK BRAKE SYSTEM (ABS) DESCRIPTION - 1. There is the following distinctive characteristics in the ABS vehicles compared with the non-ABS vehicles. Note that it does not indicate malfunction. When the brakes are applied rapidly or on a slippery road surface, the ABS will activate; the brake pedal will pulsate slightly and the vehicle and the steering wheel will vibrate slightly. When the vehicle speed reaches approximately 6 kmh (3.8 mph}, the pump motor sound is heard momentarily. This sound is due to ABS self-diagnosis. 2. By retaining or reducing the hydraulic fluid pressure in the hydraulic unit, the ABS tester is used to locate the cause of a problem within the antilock brake system. Because there is no way to check the ABS control unit itself, replace the control unit assembly only after first confirming that the other electrical parts operate normally. PREPARATION SST Wrench, flare nut 49 H026 101 A Installer, sensor rotor 49 F027 007 Attachment 072 For removal and installation of brake pipe For installation of sensor rotor (rear) For removal of sensor rotor (front) 49 0839 425C Puller set, bearing Installer, oil seal Harness, adapter For removal of sensor rotor (front) For installation of sensor rotor (front) For connection of ABS tester Gartner Banana

ANTILOCK BRAKE SYSTEM (ABS) THESE THREE MESSAGES WlLL ALTERNATE ON THE DISPLAY SCREEN AT 3 112 SE- COND INTERVALS. NOW, SELECT ONE OF THE FOUR WHEELS TO BEGIN THE DY- NAMIC T EST SEQUENCE. PRESS EITHER SWITCH UN- DER "PUSH TO EXIT" DIS- PLAY TO RETURN TO "STAT TEST DYNAM" SELECTION. IMPORTANT: WHEN ENTERING THE DY- NAMIC TEST SEQUENCE, YOU WlLL SELECT ONE OF FOUR WHEELS TO BEGIN. WHEN YOU HAVE FINISHED WITH THAT WHEEL TEST. YOU SHOULD RETURN TO 6A "WHEEL SELECTION". TO SELECT ANOTHER WHEEL. AND REPEAT THESE TEST PROCEDURES FOR ALL FOUR WHEELS. 68. WHEEL SENSOR TEST NOTE: FOR EAcn OF TnE WHEEL TESTS. IT IS NECESSARY TO RAISE THE WHEEL(S) BEING TESTED OFF THE FLOOR. (WHEN TESTING REAR WHEELS. BOTH WHEELS MUST BE RAISED OFF THE FLOOR.) DISPLAY WlLL SHOW THE WHEEL WHICH YOU SELECTED IN EST 6A I HAVE YOUR ASSISTANT SPlN THE WHEEL INDICATED WHILE YOU WATCH THE TESTER. IF SPEED IS INCORRECT, TESTER WlLL DISPLAV: SPIN SLOWER I Gartner Banana

ANTILOCK BRAKE SYSTEM (ABS) P 6B. WHEEL SENSOR TEST 6C. SOLENOID TEST (Cont.) I I NOfE: EACH OFTHE TWO SOLENOID TESTS FOR EACH WHEEL CAN BE CONDUCTED FOR A MAXIMUM OF 15 SECONDS. IF TIME LIMIT IS EXCEEDED. TESTER WILL DISPLAY: I TRY TEST AGAIN I PUSH TEST 1 I PUSH EITHER SWITCH TO START THIS TEST. TESTER WILL DISPLAY: PRESS BRK.. . HOLD I APPLY FIRM PRESSURE TO BRAKE PEDAL. AND FIRMLY THROUGH SOLENOID TEST 1 AND TEST 2. I t (Cont.) Gartner Banana

ANTILOCK BRAKE SYSTEM (ABS) P ABS CONTROL UNIT 35-PIN CONNECTOR OHMMETER 15UOPX-OI Check rotor Check the rotor for missing or damaged teeth and replace as necessary. Check alternator Refer to section G. Check wheel-speed sensor Caution To prevent damage to the terminals, create a probe by wrapping a thin wire around the tester lead before inserting. 1. Using an ohmmeter, check for continuity at the control unit connector terminals. 0----0: Indicates continuity Right front Left rear Right rear 2. If the continuity is not as specified, check the wiring har- ness (Wheel-speed sensor - Control unit). 3. If the continuity is OK, check voltage between 1K and 1 G, 10 and 1 Q, 1 U and 1 F, and 1 L and 1 P while rotating the wheel one rotation per second by hand. 4. If voltage is not approximately 50 mV--60 mV, the wheel-speed sensor is faulty. 5. If voltage is approximately 50 mV-60 mV, the control unit is faulty. 1L Check hydraulics Verify that all brake fluid connections are tight and that no fluid is leaking. IP 1Q Left front 0--0 Check hydraulic unit wiring 1. Verify that the hydraulic unit connectors are properly secured. 2. Verify that the valve relay and motor relay are properly secured. IG 1K 0-4 1U 10 S-0 IF 0-4 Gartner Banana

-01 ABS CONTHOL UNIT (Fa) 10-02 ABS HYDRAULIC UNIT (F) , WlRlNQ DIAQRAM -03 ABS HYDRAULIC UNIT 10-04 ABS WHEEL SPEED SENSOR LF(F) 10-05 ABS MEL SPEEO SENSOR W(F) 0 -06 ABS WHEEL SPEEO =ANTILOCK BRAKE SYSTEM SENSOR LR (R) 10-07 ABS WHEEL SPEED SENSOR RR(R) I I Gartner Banana

ANTILOCK BRAKE SYSTEM (ABS) ABS WHEEL SPEED SENSOR (FRONT) Removal 1 Inspection / Installation 1. Removal in the order shown in the figure. 2. Install in the reverse order of removal. I. Connector 2. Bolts 3. Bolt 4. Wheel speed sensor lnspection . . . . . . . . . . . . . . . . . . . . . . . below Inspection Wheel speed sensor 1. Measure resistance between terminals of the wheel speed sensor. Resistance: 1 .&I .2 kQ 2. If not as specified, replace the wheel speed sensor. Gartner Banana

ANTILOCK BRAKE SYSTEM (ABS) P ABS SENSOR ROTOR (FRONT) Removal l Inspection / lnstallation 1. Inspect the ABS sensor rotor for missing and damaged teeth. Note The sensor rotor does not need to be removed unless you are replacing it. 2. Remove in the order shown in the figure, referring to Removal Note. 3. Install in the reverse order of removal, referring to lnstallation Note. 25UOPX-03 1. Wheel hub 2. ABS sensor rotor .......... Removal / Installation section M Removal Note ................... below Installation Note ................. below Removal note ABS sensor rotor Remove the sensor rotor from the wheel hub with the SST. lnstallation note ABS sensor rotor Press a new sensor rotor onto the wheel hub with the SST. Gartner Banana

ANTILOCK BRAKE SYSTEM (ABS) ABS WHEEL SPEED SENSOR (REAR) Removal 1 Inspection I Installation 1. Remove the filler pipe protector (left side). 2. Remove the spare tire (right side). 3. Remove in the order shown in the figure. 4. Install in the reverse order of removal. 1. Connector 2. Mud guard 3. Bolts 4. Wheel speed sensor lnspection . . . . . . . . . . . . . . . . . . . . . . . below lnspection Wheel speed sensor 1. Measure resistance between terminals of the wheel speed sensor. Resistance: 1 .O-1.2 kR 2. If not as specified, replace the wheel speed sensor. Gartner Banana

ANTILOCK BRAKE SYSTEM (ABS) P ABS SENSOR ROTOR (REAR) Removal / Inspection 1. Inspect the ABS sensor rotor for missing and damaged teeth. Note The sensor rotor does not need to be removed unless you are replacing it. 2. Remove in the order shown in the figure, referring to Removal Note. 25uopx-o: 1. Drive shaft 2. Sensor rotor Removal . :. . . . . . . . . . . . . . . . . . . section M Removal Note . . . . . . . . . . . . . . . . . . . below 3. Boot band and boot Removal note Sensor rotor Tap the sensor rotor off the drive shaft with a chisel. Gartner Banana

P ANTILOCK BRAKE SYSTEM (ABS) -.A 1. Sensor rotor 3. Drive shaft ................... ................. Installation Note below Installation section M 2. Boot and boot band ................... Installation section M lnstallation note ABS sensor rotor Set a new sensor rotor on the drive shaft and press it on with the SST. Gartner Banana