1995 ISUZU TROOPER Workshop Manual

REAR WHEEL ANTILOCK BRAKE SYSTEM 5A3-9
CHART A
Rr.ABS Light "OFF" and will not Self Check
• CHECK THAT THE EBCM HARNESS CONNECTOR IS FULLY PLUGGED IN TO THE EBCM.
• PLUG CONNECTOR FULLY, AND RECHECK THE SELF
CHECK.
• CHECK FOR OPEN CIRCUIT IN EBCM GROUND WIRE, OR LOOSE CONNECTOR PIN, AND RECHECK THE SELF
CHECK.
DETERMINE REASON FOR BLOWN FUSE. REPAIR AS
REQUIRED, THEN RECHECK THE SELF CHECK AND RETEST VEHICLE. •
DISCONNECT
THE BATTERY AND EBCM HARNESS
CONNECTOR. CHECK FOR RESISTANCE BETWEEN
CONNECTOR PIN (15) AND CHASSIS GROUND WHILE
SHAKING THE HARNESS.
• CONNECT THE BATTERY, AND START THE ENGINE. CHECK FOR VOLTAGE BETWEEN EBCM HARNESS
CONNECTOR PIN (2) AND CHASSIS HARNESS GROUND WHILE SHAKING THE HARNESS.
Continued on the next page
EBCM
~ Electronic Brake Control Module

5A3-1 0 REAR WHEEL ANTI LOCK BRAKE SYSTEM
Continued from the previous page
I
I
I CONSTANT READING OF VOLTAGE J CONSTANT READING OF VOLTAGE I ERRATIC VOLTAGE READING. I OVER 9 V
UNDER 9 V
I ,. REPLACE THE EBCM, AND I • CHECK Rr. ABS LIGHT BULB. I REPAIR THE HARNESS. I RECHECK THE SELF CHECK.
I
I BULB IS NOT OK. I BULB IS OK.
1 I REPLACE BULB, AND RECHECK THE J CHECK FOR OPEN CIRCUIT
SELF CHECK. BETWEEN LIGHT FUSE C-10 IN INSTRUMENT PANEL AND THE EBCM HARNESS CONNECTOR PIN (2). REPAIR AS REQUIRED, AND RECHECK THE SELF CHECK.
EBCM
-Electronic Brake Control Module
•

REAR WHEEL ANTILOCK BRAKE SYSTEM 5A3-11
CHART B
Brake Light 110N" Rr. ABS Light "OFF' and Does Self Check
• START THE ENGINE, AND CHECK FOR BRAKE LIGHT.
• RELEASE PARKING BRAKE IF APPLIED.
J
I
I BRAKE LIGHT GOES OFF. J BRAKE LIGHT REMAINS ON.
I
I DISREGARD FAILURE. J • DISCONNECT THE PARKING BRAKE SWITCH CONNEC-
TOR FROM THE SWITCH, AND RECHECK FOR BRAKE LIGHT.
I
I
I BRAKE LIGHT GOES OFF. I BRAKE LIGHT REMAINS ON.
I I ADJUST OR REPLACE PARKING BRAKE SWITCH, AND J • DISCONNECT THE PRESSURE DIFFERENTIAL WARNING RECHECK IT.
SWITCH CONNECTOR
FROM THE SWITCH, AND RECHECK FOR BRAKE LIGHT.
I
I
I BRAKE LIGHT GOES OFF. I BRAKE LIGHT REMAINS ON.
j
I CHECK COMBINATION VALVE. REFER TO "HYDRAULIC I • DISCONNECT THE EBCM HARNESS CONNECTOR FROM
BRAKES" (SEC. 5A) FOR DIAGNOSIS.
EBCM, AND RECHECK FOR BRAKE LIGHT.
I
I
I BRAKE LIGHT GOES OFF. I BRAKE LIGHT REMAINS ON.
I
I REPLACE EBCM, AND RECHECK IT. I CHECK FOR SHORT TO GROUND IN BRAKE LIGHTWIRE,AND
REPAIR AND RECHECK THE SELF CHECK.
EBCM
= Electronic Brake Control Module

5A3~12 REAR WHEEL ANTILOCK BRAKE SYSTEM
CHART C
Rr. ABS and Brake Lights 110N"
(No Flashout Code}
I • CHECK FOR BRAKE FLUID LEVEL AT THE RESERVOIR TANK.
I
I FLUID LEVEL LOW. I FLUID LEVEL OK.
I
• FIND AND REPAIR CAUSE OF LEAKAGE, AND RECHECK I • DISCONNECT THE HARNESS CONNECTOR FROM THE
SELF CHECK. COMBINATION SWITCH, AND START THE ENGINE, AND CHECK FOR LIGHTS.
I BOTH LIGHTS GO OFF. I BOTH LIGHTS REMAIN ON.
I
CHECK BRAKE SYSTEM FOR AIR IN LINES OR MECHANICAL I IGN. KEY OFF. DAMAGE, AND RECHECK THE SELF CHECK.
• DISCONNECT THE EBCM HARNESS CONNECTOR FROM EBCM, AND START THE ENGINE, AND CHECK uRr ABS" AND UBRAKE" LIGHTS.
I Rr. ABS LIGHT ON.
I
BRAKE LIGHT ON.
I I BOTH LIGHTS OFF. BRAKE LIGHT OFF. Rr. ABS LIGHT OFF.
I • CHECK FOR SHORT TO GROUND I • CHECK FOR SHORT TO GROUND I I
• CHECK FOR FUSE F-91N THE FUSE IN REAR ABS LIGHT WIRE. IN COMBINATION SWITCH WIRE. BOX OF ENGINE COMPARTMENT.
I I REPAIR
SHORT TO GROUND IN I REPAIR SHORT TO GROUND, AND J Continued on the next page REAR ABS LIGHT CIRCUIT, AND RECHECK THE SELF
CHECK.
RECHECK THE SELF CHECK.
EBCM -
Electronic Brake Control Module
•

REAR WHEEL ANTILOCK BRAKE SYSTEM 5A3-13
Continued from the previous page
• CHECK AND REPAIR ALL CIRCUITS FUSE IS PROTECTING FOR SHORTS TO GROUND. REPLACE FUSE, AND RECHECK THE SELF CHECK. •
DISCONNECT
THE EBCM HARNESS CONNECTOR FROM
EBCM, AND TURN THE IGNITION KEY TO THE ON POSITION, CHECK FOR VOLTAGE BETWEEN PIN (13) AND CHASSIS GROUND WHILE SHAKING THE HARNESS.
CONSTANT READING OF VOLTAGE OVER 9V CONSTANT READING OF VOLTAGE UNDER9V
Continued on the next page
EBCM -
Electronic Brake Control Module

5A3-14 REAR WHEEL ANTILOCK BRAKE SYSTEM
Continued from the previous page
• CHECK FOR FUSE C-14 IN THE FUSE BOX OF INSTRUMENT PANEL
FUSE IS BLOWN. FUSE IS OK.
•
CHECK AND REPAIR ALL CIRCUITS FUSE IS PROTECTING FOR SHORTS TO GROUND. REPLACE FUSE, AND RECHECK THE SELF CHECK.
• DISCONNECT THE EBCM HARNESS CONNECTOR FROM EBCM, AND CHECK FOR VOLT AGE BETWEEN PIN (1 0) AND CHASSIS GROUND WHILE SHAKING THE HARNESS.
CONSTANT READING
OF VOLTAGE OVER 9 V
• CHECK FOR RESISTANCE BETWEEN PIN (7) AND CHASSIS
GROUND WHILE SHAKING THE HARNESS.
CONSTANT READING
OF OVER 1 OOK OHMS
REPLACE THE EBCM, AND RECHECK SYSTEM. CONSTANT
READING
OF VOLTAGE UNDER 9 V
REPAIR OPEN CIRCUIT
CONSTANT
READING OF UNDER 100K OHMS
REPAIR SHORT CIRCUIT TO
THE GROUND. ERRATIC
VOLTAGE
READING.
REPAIR THE HARNESS.
ERRATIC RESISTANCE READING.
REPAIR
THE HARNESS.
EBCM = Electronic Brake Control Module
•

REAR WHEEL ANTILOCK BRAKE SYSTEM 5A3-15
CHART D
Rr. ABS and Brake Lights Flashing
• TURN THE IGNITION KEY TO THE OFF POSITION, AND DISCONNECT THE EBCM HARNESS CONNECTOR FROM EBCM AND IGN. KEY ON CHECK FOR VOLTAGE AT PIN {13) OF EBCM HARNESS CONNECTOR AND CHASSIS GROUND WHILE
SHAKING THE BODY HARNESS AND REAR BODY HARNESS.
REPAIR THE HARNESS FOR OPEN CIRCUIT, AND RECHECK • DISCONNECT BATTERY, AND CHECK FOR RESISTANCE AT PIN {7) OF THE EBCM HARNESS CONNECTOR AND CHASSIS GROUND WHILE SHAKING THE BODY
HARNESS AND REAR BODY HARNESS.
THE SYSTEM.
•
CHECK FOR RESISTANCE AT PIN {15) OF EBCM HARNESS
CONNECTOR, AND CHASSIS GROUND WHILE SHAKING THE BODY HARNESS AND REAR BODY HARNESS.
REPAIR OPEN CIRCUIT
IN WIRE TO PIN {15) CONNECTOR, AND RECHECK THE SYSTEM.
EBCM = Electronic Brake Control Module

5A3-16 REAR WHEEL ANTILOCK BRAKE SYSTEM
CHART E
Rear Wheels Lock with Hard Stops
(Rr. ABS and Brake Lights Self Check Properly)
• APPLY THE BRAKE PEDAL AND CHECK FOR STOP LIGHTS.
STOP LIGHTS WILL NOT ILLUMINATE.
CHECK STOP LIGHT SWITCH OR CIRCUIT, AND REPAIR AS
NECESSARY, AND RECHECK IT.
EXCITER RING IS MISSING, OR TEETH ARE MISSING.
REPLACE
THE EXCITER RING.
VOLTAGE
UNDER 650 mV ON AC SCALE
REPLACE
THE SPEED SENSOR, AND RECHEK SENSOR
OUTPUT.
REAR BRAKES OK.
REPLACE THE EBCM.
STOP LIGHTS OK.
• REMOVE THE SENSOR FROM THE REAR AXLE CASE, AND CHECK FOR MISSING EXCITER RING, OR TEETH MISSING.
EXCITER
RING IS PRESENT, AND TEETH ARE INTACT.
• REINSTALL
THE SENSOR AND RAISE REAR WHEELS TO
SAFELY CLEAR THE FLOOR.
• START ENGINE, AND TURN REAR WHEEL AT 5 MPH.
• REMOVE THE LEFT HAND KICK PANEL, AND USING A
VOLTMETER SET ON THE AC SCALE, CHECK FOR VOLTAGE AT THE TWO PINS OF THE SENSOR TEST
CONNECTOR.
VOLTAGE
OVER 650 mV ON AC SCALE
• REINSTALL
THE KICK PANEL, AND CHECK THE REAR BRAKE FOR MECHANICAL PROBLEMS SUCH AS GRABBING, LOCKING OR PULLING.
REAR BRAKES LOCK, GRAB OR PULL.
REPAIR THE REAR BRAKE PROBLEMS.
EBCM = Electronic Brake Control Module
•