brake ISUZU TROOPER 1995 Workshop Manual

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
•

REAR WHEEL ANTILOCK BRAKE SYSTEM 5A3-17
DIAGNOSTIC TROUBLE CODES
FLASHOUT CODES CHART
CONDITION ACTION TO
TAKE
Rr. ABS light flashes 2 times. See Flashout Diagnostic
(High resistance
isolate circuit or malfunctioning EBCM) Trouble Code (DTC) 2
Rr. ABS light flashes 3 times. See Flashout DTC 3
(High resistance
dump circuit or malfunctioning EBCM)
Rr. ABS light flashes 4 times.
See Flashout DTC 4
(Closed rear wheel antilock valve switch)
Rr. ABS light flashes 5 times.
See Flashout DTC 5
System dumps
too many times in 2WD (2WD and 4WD vehicles)
condition
Occurs while making normal or hard stops. Rear brake may lock.
Rr. ABS light flashes 6 times.
See Flashout DTC 6
(Erratic speed sensor reading
while driving)
Rr. ABS light flashes 7 times. See Flashout DTC 7
Isolation output missing or antilock valve wiring shorted to ground
Rr. ABS light flashes 8 times.
See Flashout DTC 8
Dump
output missing or antilock valve wiring shorted to ground
Rr. ABS light flashes 9 times. See Flashout DTC 9
(High sensor resistance)
Rr. ABS light flashes 10 times.
See Flashout DTC 1 0
(Low sensor resistance)
Rr. ABS light flashes 11 times.
See Flashout DTC 11
Stop light switch circuit defective, condition indicated only when driving
above
56 km/h (35 mph)
Rr. ABS light flashes 13 times.
See Flashout DTC 13
(Speed processor check EBCM)
Rr. ABS light flashes 14 times.
See Flashout DTC 14
(Program check
EBCM)
Rr. ABS light flashes 15 times.
See Flashout DTC 15
(Memory failure EBCM)
NOTE:
• Codes 1, 12 and over 15 are not utilized for the diagnostic mode.
EBCM = Electronic Brake Control Module

5A3-18 REAR WHEEL ANTILOCK BRAKE SYSTEM
DIAGNOSIS PROCEDURE
FLASHOUT DIAGNOSTIC TROUBLE CODE 2
(HIGH RESISTANCE ISOLATE CIRCUIT OR MALFUNCTIONING EBCM)
Antilock valve
Isolate.
Retest SW.
(EBCM)
Dump
• DISCONNECT THE BATIERY GROUND CABLE.
• DISCONNECT THE EBCM HARNESS CONNECTOR FROM EBCM, AND
CHECK FOR RESISTANCE BETWEEN EBCM HARNESS CONNECTOR PIN (1) AND CHASSIS GROUND WHILE SHAKING THE HARNESS.
CONSTANT READING
OF RESISTANCE 3 TO 6 OHMS
CHECK EBCM VALVE AND GROUND CONNECTION
NO
PROBLEM IN EBCMIVALVE AND GROUND CONNECTION.
CONNECT
EBCM TO HARNESS CONNECTOR THEN TURN IGNITION ON.
NO CODE
2 INDICATED
REPLACE ANTILOCK VALVE AND RECHECK
THE SELF CHECK AND RETEST VEHICLE.
PROBLEM FOUND REPAIR CONNECTION(S) AND/OR GROUND
CODE 2 RETURNS
REPLACE EBCM AND
RECHECK THE SELF CHECK.
EBCM
= Electronic Brake Control Module
4!1
Continued on the next page
•

REAR WHEEL ANTILOCK BRAKE SYSTEM 5A3-19
Continued from the previous page
• DISCONNECT ANTI LOCK VALVE HARNESS CONNECTOR, AND CHECK FOR RESISTANCE BETWEEN GROUND PIN (3) OF VALVE HARNESS CONNECTOR AND CHASSIS
HARNESS GROUND WHILE SHAKING THE HARNESS.
CONSTANT READING
RESISTANCE
OVER 1 OHM OF
REPAIR OPEN CIRCUIT IN VALVE GROUND WIRE HARNESS OR LOOSE CONNECTOR PINS, AND RECHECK THE SELF CHECK.
Valve connector
CONSTANT READING OF RESISTANCE UNDER 1 OHM
•
CHECK FOR RESISTANCE BETWEEN ISOLATION PIN (4) AND
GROUND PIN (3) OF VALVE
CONNECTOR.
Harness connector
REPAIR OPEN ISOLATION SOLENOID WIRE FROM THE VALVE TO EBCM OR LOOSE PINS IN CONNECTOR, AND RECHECK THE SELF CHECK.
REPLACE THE ANTILOCK VALVE, AND RECHECK THE SELF CHECK.
EBCM ~ Electronic Brake Control Module

5A3-20 REAR WHEEL ANTILOCK BRAKE SYSTEM
FLASHOUT DIAGNOSTIC TROUBLE CODE 3
(HIGH RESISTANCE DUMP CIRCUIT OR MALFUNCTIONING EBCM)
Anti lock valve
Isolate.
Reset SW.
(EBCM)
Dump
• DISCONNECT THE BATTERY GROUND CABLE.
• DISCONNECT EBCM HARNESS CONNECTOR FROM EBCM,
AND CHECK FOR RESISTANCE BETWEEN EBCM HARNESS CONNECTOR PIN (9) AND CHASSIS GROUND WHILE SHAKING THE HARNESS.
CONSTANT READING
OF RESISTANCE 1 TO 3 OHMS
CHECK EBCM
VALVE AND GROUND CONNECTION
NO
PROBLEM IN EBCMIVALVE AND
GROUND CONNECTION.
CONNECT EBCM TO HARNESS CONNECTOR
THEN TURN IGNITION ON.
NO CODE 31NDICATED
REPLACE ANTILOCK
VALVE AND RECHECK THE SELF CHECK AND RETEST VEHICLE.
PROBLEM FOUND REPAIR CONNECTION(S) AND/OR GROUND
CODE 3 RETURNS
REPLACE EBCM
AND RECHECK THE SELF
CHECK.
EBCM
~ Electronic Brake Control Module
4Q
1.5 !l
Continued on the next page
•

REAR WHEEL ANTILOCK BRAKE SYSTEM 5A3-21
Continued from the previous page
• DISCONNECT ANTILOCK VALVE HARNESS CONNECTOR, AND CHECK FOR RESISTANCE BETWEEN GROUND PIN (3) OF VALVE HARNESS CONNECTOR AND CHASSIS
HARNESS GROUND WHILE SHAKING THE HARNESS.
CONSTANT READING
RESISTANCE
OVER 1 OHM
Valve
connector
OF CONSTANT READING OF RESISTANCE UNDER 1 OHM
•
CHECK FOR RESISTANCE BETWEEN DUMP PIN (1) AND
GROUND PIN (3) OF VALVE
CONNECTOR Harness
connector
REPAIR OPEN DUMP SOLENOID WIRE FROM THE VALVE TO THE EBCM OR LOOSE PINS IN THE CONNECTOR, AND RECHECK THE SELF CHECK.
REPLACE THE ANTILOCK VALVE, AND RECHECK THE SELF CHECK.
EBCM -Electronic Brake Control Module

5A3-22 REAR WHEEL ANTILOCK BRAKE SYSTEM
FLASHOUT DIAGNOSTIC TROUBLE CODE 4
(CLOSED REAR WHEEL ANTILOCK VALVE SWITCH)
Isolate.
Reset SW.
(EBCM)
Dump
Valve connector
Anti lock valve
• DISCONNECT ANTILOCK VALVE CONNECTOR, AND CHECK FOR RESISTANCE BETWEEN THE VALVE CONNECTOR RESET SWITCH PIN {2) AND THE VALVE BODY.
4Q
CONSTANT READING OF RESISTANCE UNDER 10K OHMS
CONSTANT READING OF RESISTANCE OVER 10K OHMS
REPLACE ANTILOCK VALVE, AND RECHECK THE SELF CHECK.
Valve connector
• CHECK FOR RESISTANCE BETWEEN THE VALVE CONNECTOR RESET SWITCH PIN {2) AND GROUND PIN (3).
Continued on the next page
•

REAR WHEEL ANTILOCK BRAKE SYSTEM 5A3-23
Continued from the previous page
CONSTANT READING OF RESISTANCE UNDER 10K OHMS
REPLACE ANTILOCK VALVE, AND RECHECK THE SELF
CHECK. CONSTANT
READING
OF RESISTANCE OVER 10K OHMS
• DISCONNECT
THE EBCM HARNESS CONNECTOR FROM
EBCM, AND CHECK FOR RESISTANCE BETWEEN EBCM HARNESS CONNECTOR PIN (4) AND CHASSIS GROUND WHILE SHAKING THE HARNESS.
CONSTANT READING
OF CONSTANT READING OF ERRATIC RESISTANCE READING RESISTANCE UNDER 100K OHMS
REPAIR SHORT IN VALVE RESET
WIRE FROM VALVE TO EBCM HARNESS CONNECTOR, AND
RECHECK THE SELF CHECK. RESISTANCE
OVER 100K OHMS
CONNECT
EBCM TO HARNESS
CONNECTOR, THEN TURN IGNITION
ON. REPAIR THE HARNESS
NO CODE 41NDICATED,
OR WHEN PRESS THE BRAKE PEDAL AS HARD AS POSSIBLE, CODE 4 RETURNS. CODE 4 RETURNS WITHOUT BRAKE APPLICATION
REPLACE ANTI LOCK VALVE AND RECHECK THE SELF CHECK AND RETEST VEHICLE. REPLACE EBCM, AND RECHECK THE SELF CHECK.
EBCM
-Electronic Brake Control Module

5A3-24 REAR WHEEL ANTILOCK BRAKE SYSTEM
FLASHOUT DIAGNOSTIC TROUBLE CODE 5
(SYSTEM DUMPS TOO MANY TIMES IN 2WD CONDITION)
4WD
(EBCM)
4WDSW.
I•
I • CHECK IF FAILURE OCCURS IN 2WD MODE OR 4WD MODE. I
I I (2WD MODE) (4WD MODE)
• DISCONNECT THE EBCM HARNESS CONNECTOR FROM • DISCONNECT THE EBCM HARNESS CONNECTOR FROM
EBCM. EBCM.
J I • DRIVE THE VEHICLE IN 2WD MODE. • TURN
THE IGNITION KEY TO "ON".
l I • CHECK FOR CONDITION OF THE REAR BRAKE SYSTEM. • SHIFT TO 4WD MODE.
I
I I I REAR BRAKES TEND REAR BRAKES ARE
~
• CHECK FOR VOLTAGE BETWEEN HARNESS CONNEC-
TO LOCK UP EASILY. NORMAL. TOR PIN (3) AND CHASSIS GROUND WHILE SHAKING
I I
THE HARNESS.
~ 1S
REPAIR REAR BRAKE REPLACE
ANTI LOCK EBCM harness
connector
SYSTEM, AND RETEST VALVE, AND
RETEST ·'"·. ~)l VEHICLE. VEHICLE. [1l21314l~ 5161718) .......
J9J1oJ11J12r13 14J15J1sJ 11] = Pin (3)
~-~\
~ -~~~
"!!'
ERRATIC RESISTANCE READING. I I CONSTANT READING OF VOLTAGE I I CONSTANT
READING OF VOLTAGE
UNDER 1 V OVER 1 V
REPAIR THE HARNESS I I REPLACE ANTILOCK VALVE, AND I I REPEAT 4WD INDICATOR
SWITCH, RETEST VEHICLE. AND RETEST VEHICLE.
EBCM
~ Electronic Brake Control Module
I
•

REAR WHEEL ANTILOCK BRAKE SYSTEM 5A3-25
FLASHOUT DIAGNOSTIC TROUBLE CODE 6
(ERRATIC SPEED SENSOR READING WHILE DRIVING)
(EBCM)
Speed sensor
Test connectors Speed sensor
• DISCONNECT THE BATTERY GROUND CABLE.
• DISCONNECT THE EBCM HARNESS CONNECTOR FROM EBCM, AND
CHECK FOR RESISTANCE BETWEEN HARNESS CONNECTOR PINS, (17
AND 16) WHILE SHAKING THE HARNESS FROM SPEED SENSOR TO EBCM.
EBCM harness connector
Pin (17)
ERRATIC RESISTANCE READING.
REPAIR LOOSE CONNECTION
IN THE SPEED SENSOR
CIRCUITS; CHECK FOR DIRTY OR LOOSE PINS AND FRAYED OR SHORTED CONNECTORS AND RETEST VEHICLE.
METAL CHIPS ARE PRESENT.
DRAIN
AND CLEAN DIFFERENTIAL. CHECK EXCITER RING FOR BROKEN OR CHIPPED TEETH. RETEST VEHICLE.
TEETH ARE DAMAGED, OR LATERAL RUNOUT OF EXCITER
RING IS VISIBLE.
Continued on the next page
CONSTANT READING 1000 TO 2000 OHMS
•
CHECK FOR A BUILD-UP OF METAL CHIPS ON SPEED
SENSOR MAGNETIC POLE PIECE.
NO METAL CHIPS ARE PRESENT.
• ROTATE EXCITER RING,
AND CHECK FOR DAMAGE TO TEETH.
TEETH
ARE INTACT, AND NO VISIBLE LATERAL RUNOUT IS OBSERVED.
Continued on the next page
EBCM
= Electronic Brake Control Module