ISUZU TROOPER 1995 Workshop Manual

CRUISE CONTROL 98-7
DIAGNOSIS
~ QUICK CHART FOR CHECK POINTS
"0 !!:! 0 0 CD 0 <( ::I ;: w ... Cl) Qi :0 0 <( Cl) 0 0 g Cl) u .r: .r: CD 0. 0 Cl) ::I CD CD .!!! .!!! c: i==" 0 ""'" E :c 0 ::I 0 Qi :::1 "0 c: :0 en ... 0 '6 Cl) Cl) ::I ::I ·;a ::I :::1 ... u w w .... ::I CD .,. ·= > .s <( ~ 1-u
0
0 0
0
0 0
0 0
0 0
0 0 1. Cruise control inoperative (
1) (2) (12) (3)
(4) (51 (6) (7) (8) (9) (10) (11)
0 0
0
0 0 0 2. Cruise
speed unstable (5) (3) ( 1) (2) (6) (4)
3. Cruise control cancels 0 0 0
0 0
(51 (
1) (2) (4) (3)
0 0 0 4. RESUME
inoperative (3) ( 1) (2)
0
0 0 5. ACCEL or TAP-UP
inoperative (3) ( 1) (2)
0
0 0 6. COAST or TAP-DOWN
inoperative (2) ( 1) (3)
0 0 0 0 7. Cruise control
cancel (4) ( 1) (2) (3)
0
0 8. Cruise control does not operate to kick down (2) (
1) from 0/D to 3rd, when cruising speed is less than approximately 3 mph or more from preset
speed (A/T). However, avoid the 0/D cancel in the following conditions:
1) When the cruising speed is 75 mph or more
during the
Accelerate function. 21 When accelerated from the speed at 70 mph. 3) When the cruising speed is 75 mph or more
during the Resume function.
4) When the memory speed is less than 3 mph
during the Resume function.
51 When resumed from the memory speed at
6 mph or less. 61 While in the Tap-up function.
9. Indicator light does not light 0 0 0
0 (
1) (4) (2) (3)
NOTE: Figure in parenthesis"()" indicates the order of inspection.

98-8 CRUISE CONTROL
QUICK CHART FOR POSSIBLE CAUSE
1. Cruise control inoperative
CHECK POINTS POSSIBLE CAUSE
Fuse C-4 (10A) Burned out
Cruise control main relay Defective circuit inside relay
Main switch
Contact point does not switch to ON
SET/COAST SW Contact point does not switch to ON
Clutch switch (M/T)
Contact point does not switch to ON
Brake switch Normal close side of point does not switch to ON
Pump & VSV Defective valve or vacuum pump (inoperative)
Vehicle speed sensor Open or short circuit
Vacuum hose Disconnected, Bent, Crack, Crush
Actuator Restriction
or out of link
Cable
harness Disconnected connector, Open circuit
Cruise
control unit Defective circuit inside control unit
2. Cruise speed unstable
CHECK POINTS POSSIBLE CAUSE
Vehicle
speed sensor Open or short circuit
Vacuum hose
Disconnected, Bent, Cracked, Crushed
Pump & VSV Defective valve (leakage)
Actuator Restriction,
defective or disconnected
Cruise
control unit Defective circuit inside control unit
Accelerator cable
Incorrect free play of accelerator pedal COUNTERMEASURE
Replace
Replace
Repair or replace
Refer to cruise control
SW
inspection
Refer
to clutch SW
inspection
Refer
to brake SW
inspection
Replace
Refer to speedometer
inspection
Repair
or Replace
Repair or Replace
Repair
Replace
COUNTERMEASURE
Refer to speedometer
inspection
Repair
or Replace
Replace
Repair or Replace
Replace
Readjust
•

-------------------
CRUISE CONTROL 98-9
3. Cruise control cancels
CHECK POINTS POSSIBLE CAUSE COUNTERMEASURE
Clutch switch
(M/T) Unstable point contact Replace
Incorrect
switch position Readjust
Clutch
pedal does not return fully Check and repair return
spring
Brake switch
Unstable normal close point contact Replace
Incorrect
switch position Readjust
Brake
pedal does not return fully Check and repair return
spring
Car speed sensor
Open or short circuit Refer to speedometer
inspection
Pump& VSV Defective valve (leakage) Replace
Cruise control unit Defective circuit inside control unit Replace
4. RESUME inoperative
5. ACCEL or TAP-UP inoperative
CHECK POINTS POSSIBLE CAUSE COUNTERMEASURE
Resume switch
Contact
point does not switch to ON Refer to cruise control
SW
inspection
Cable harness Open circuit for resume switch circuit Repair
Cruise
control unit Defective circuit inside control unit Replace
6 COAST or TAP-DOWN inoperative ,,
CHECK POINTS POSSIBLE CAUSE COUNTERMEASURE
SET/COAST
SW Poor point contact Refer to cruise control
SW
inspection
Cruise
control unit Defective circuit inside control unit Replace
Cable
harness Open circuit for coast switch circuit Repair

98-10 CRUISE CONTROL
7. Cruise control does not cancel
CHECK POINTS POSSIBLE CAUSE COUNTERMEASURE
Clutch switch Point does not switch to OFF Replace
Brake switch
Normal close point does not switch to OFF Replace
Normal open point does not switch to ON
Mode switch Point does not switch to OFF Repair or replace
Cruise control unit
Defective citcuit inside control unit Replace
Transmission Control Open circuit for TCM or defective circuit inside Refer to Section
7 A 1
Module (TCM) control unit
8. Cruise control does not operate to kick down from 0/D to 3rd, when cruising speed is less than
approximately 3 mph or more from preset speed (A/T)
CHECK POINTS POSSIBLE CAUSE COUNTERMEASURE
TCM Defective circuit inside TCM Refer
to Section 7 A 1
Cable harness Open circuit for TCM
Repair
9. Indicator light does not light
CHECK POINTS POSSIBLE CAUSE COUNTERMEASURE
Fuse
C-10 (10A) Burned out Replace
Indicator
bulb Bulb filament burned out Replace
Cable
harness Disconnected connector, Open circuit Repair
Cruise
control unit Defective circuit inside control unit Replace
..

CRUISE CONTROL 98-11
1. CHECKING PROCEDURE OF THE CRUISE CONTROL
POWER CIRCUIT
(CHART 1)
TURN THE STARTER SWITCH AND THE CRUISE
CONTROL MAIN SWITCH ON.
• IS THERE ANY BATTERY VOLTAGE APPLIED BETWEEN THE HARNESS SIDE CONNECTORS
sl B-9IAND 9IB-91?
• IS THERE ANY BATTERY VOLTAGE APPLIED
BETWEEN THE FUSE C-4 (10Al AND THE
GROUND?
• DISCONNECT THE CONNECTOR OF THE CRUISE
CONTROL MAIN SWITCH.
• IS THERE ANY BATTERY VOLTAGE APPLIED
BETWEEN THE SWITCH HARNESS SIDE
CONNECTOR a [I§] AND THE GROUND?
CONTINUED ON FOLLOWING PAGE
REPAIR A POOR CONNECTION OF THE CONNECTORS OR AN OPEN CIRCUIT BETWEEN THE STARTER
SWITCH
AND THE FUSE.

98-12 CRUISE CONTROL
CONTINUED FROM PREVIOUS PAGE
~ $
• IS THE CONTINUITY IN THE CRUISE CONTROL .I REPAIR A POOR CONNECTION OF THE CONNECTORS MAIN SWITCH NORMAL? OR AN OPEN CIRCUIT BETWEEN THE FUSE C-4 (10Al
AND B[E[].
~ $
• REMOVE THE CRUISE MAIN RELAY. REPAIR OR REPLACE THE SWITCH.j
• IS THE RELAY NORMAL?
~ $
• IS THERE ANY BATTERY VOLTAGE APPLIED
REPAIR OR REPLACE THE RELAY. I BETWEEN THE CRUISE MAIN RELAY HARNESS
SIDE CONNECTOR 2IX-20I AND GROUND?
~ $
• REINSTALL THE CRUISE CONTROL MAIN SWITCH. REPAIR A POOR CONNECTION OF THE CONNECTORS
• IS THERE ANY BATTERY VOLTAGE APPLIED OR AN OPEN CIRCUIT BETWEEN THE FUSE C-4 (10AI
BETWEEN 1IX-20I AND THE GROUND? AND 2IX-20 I.
~ $
• IS THERE CONTINUITY BETWEEN THE HARNESS
REPAIR A POOR CONNECTION OF CONNECTORS OR SIDE CONNECTORS 4IX-20 I AND 7 [§)? AN OPEN CIRCUIT BETWEEN 9[ill 16[W I AND 1IX-20I
CONTINUED ON FOLLOWING PAGE
..

CONTINUED FROM PREVIOUS PAGE
• IS THE CONTINUITY OF THE BRAKE SWITCH
NORMAL?
•
IS THERE CONTINUITY BETWEEN THE HARNESS
SIDE CONNECTORS 3IB-13I AND BIB-917
REPAIR
A POOR CONNECTION OF THE CONNECTORS OR AN OPEN CIRCUIT BETWEEN
2IB-13I AND 4IX-20I.
CRUISE CONTROL 98 -13
REPAIR A POOR CONNECTION OF THE CONNECTORS OR AN OPEN CIRCUIT BETWEEN 4IX-20I AND7[ill.
REPAIR A POOR CONNECTION OF THE CONNECTORS
OR AN OPEN CIRCUIT BETWEEN 3IB-13I AND Bl B-9 I.

98-14 CRUISE CONTROL
B
• IS THERE ANY BATIERY VOLTAGE APPLIED BETWEEN THE CRUISE CONTROL UNIT HARNESS
SIDE CONNECTOR
TERMINALS 12 ~AND 9 [§]]?
• DISCONNECT THE BRAKE SWITCH CONNECTORS.
• CHECK FOR CONTINUITY BETWEEN THE SWITCH
SIDE CONNECTOR TERMINALS
1 [[ll) AND 4 [[ll).
IS THERE CONTINUITY WHEN THE BRAKE
PEDAL IS PRESSED? (THERE SHOULD BE NO CONTINUITY WHEN THE
BRAKE IS RELEASED)
REPAIR A SHORT BETWEEN THE BRAKE SWITCH
CONNECTOR TERMINALS
21 B-131 AND 41 B-131, OR REPLACE THE SWITCH.
IIIII

-·
• DISCONNECT THE BRAKE SWITCH CONNECTOR. • IS THERE ANY BETTERV VOLTAGE APPLIED
BETWEEN THE SWITCH HARNESS SIDE
CONNECTOR 1 [ill] AND THE GROUND?
• IS THE CONTINUITY OF THE BRAKE SWITCH NORMAL?
• IS THERE CONTINUITY BETWEEN THE HARNESS
SIDE CONNECTOR TERMINALS 51 B-91 AND 91 B-91?
CRUISE CONTROL 98-15
REPAIR A POOR CONNECTION OF THE CONNECTORS OR AN OPEN CIRCUIT BETWEEN THE FUSE C-14 (15Al
AND
1IB-13i.
REPAIR A POOR CONNECTION OF THE
CONNECTORS OR AN OPEN CIRCUIT BETWEEN
4 ~ANDs[[9].

98 -16 CRUISE CONTROL
2. CRUISE SPEED CANNOT BE SET. (CHART 2)
• DISCONNECT THE CONNECTOR OF THE CRUISE
CONTROL SWITCH !COMBINATION SWITCH).
•
TURN THE STARTER SWITCH AND CRUISE CONTROL MAIN SWITCH ON.
• IS THERE ANY BATIERY VOLTAGE APPLIED BETWEEN
THE
CRUISE CONTROL SWITCH HARNESS SIDE
CONNECTOR 9IB-52I AND THE GROUND?
•
CHECK THE FOLLOWING:
@ INSPECTION OF THE PUMP & VSV AND THE
CIRCUIT @ INSPECTION OF THE CRUISE CONTROL SWITCH AND THE CIRCUIT
@ INSPECTION OF THE MODE SWITCH, CANCEL SWITCH !A/Tl CLUTCH SWITCH, CANCEL SWITCH (MIT} AND CIRCUIT @ INSPECTION OF THE VEHICLE SPEED SENSOR AND CIRCUIT @ INSPECTION OF THE GROUND CIRCUIT OF THE
CRUISE CONTROL UNIT. • ARE THE RESULTS OF INSPECTION NORMAL?
IF NO TROUBLE IS FOUND, REPLACE
THE
CRUISE CONTROL UNIT
VSV: VACUUM SWITCHING VALVE CHECK
THE
POWER CIRCUIT AND REPAIR IT IF
NECESSARY.
(REFER TO CHART 1)
•