1998 ISUZU TROOPER Remove engine

4B1±25 DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)
Diagnosis of the Faults Based on the
Status of 4WD Indicator Lamp, 4WD
Switch and T/F Change Lever
Diagnosis charts are shown on below. If troubles can not
be solved after every chart was traced, troubles may
occur in the 4WD control unit. In this case, replace the
4WD control unit and trace every chart again.
Fault on switching from 2WD to 4WD
1.In case that 4WD indicator's blinking changes
from 2Hz to 4Hz after Solution 1 is carried out.
Faults occur in the motor actuator or the transfer case
assembly. Remove the motor actuator and check
function. If problem was found and it was repaired, try
Solution 1 again. After that, disassemble the
transfer case assembly for check and repair or
replace. If incident is not improved after above
mentioned actions were taken, replace the 4WD
control unit.
2.In case that 4WD indicator does not blink nor
light, when switching from 2WD to 4WD.
Step
ActionYe sNo
1Is ignition turned on?
Go to Step 2
Turn on the
ignition and trace
this chart from
start.
2
Does the indicator light comes on when the engine is not started?
Go to Step 3
Burning out of
indicator lamp or
disconnection of
harness wire.
Trace this chart
from the start
after repair or
replace.
3Start the engine.
Is the 4WD switch turned from 2WD to 4WD?Short-circuit
(body short) on
harness of the
4WD switch.
Fault of the 4WD
switch (holding
the closed
condition).
Trace this chart
from the start
after repair or
replace.
Push the 4WD
switch to 4WD.

4B1±34
DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)
4. If vacuum is not applicable as much as ±400mmHg,
and if there is resistance on the intake side, replace
with a new check valve.
VSV Assembly
Inspect the vehicle side harness as follows:
412RS071
Legend
(1) Grey
(2) Blue
1. Remove connector.
2. Shift transfer lever to 2H and start the engine.
NOTE: Do not move the vehicle while inspection.
3. Make sure that there is continuity in the vehicle side of
harness. If there is no continuity, check transfer shift
switch and wiring.
Inspect both VSVs as follows:
F04RS004
1. With battery not connected (Usual).
A±C:There is continuity
B:Closed
2. With battery connected
A ± B:There is continuity
C:Closed
3. If 1) and 2) fail, replace with a new VSV.
Axle Position Switch
412RS048
1. With ball (1) being free
A ± B:There is continuity
2. With ball forced into the switch
A ± B:No continuity
3. If 1) and 2) fail, replace with a new switch.
Motor Actuator Assembly
Inspect the function of the motor actuator assembly as
follows:

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±14
How to Clear The Trouble Code
The trouble codes saved to the control unit can be deleted
by the following procedure if the starter switch is being in
the OFF position.
1. Shift the transfer lever to the neutral position between
HIGH and 4L, and short-circuit the self-diagnostic
connector.
NOTE: The neutral position between HIGH and 4L refers
to the point that turns off the TOD indicator lamps.
(However, be sure to check the position before
short-circuiting the self-diagnostic connector.)
C07RW011
2. Turn on the starter switch while maintaining the state
of step 1, and step on the brake pedal five times within
five seconds from the first step on. (Note that ªfive
timesº includes the first step on). (The TOD indicator
lamps display the 4L mode whenever the brake pedal
is stepped on.)
3. If the conditions shown in steps 1 and 2 are met, clear
the trouble codes saved to the control unit. (After the
codes are completely deleted, the code 12 that
indicates the normal condition is continuously
displayed.)
Precautions on Diagnosis
Replacement of Control Unit
The control unit itself rarely fails. In most cases, the
harnesses have failed (e.q. short-circuit) to cause
secondary troubles. Other cases include that the cause
has been unknown due to intermittent occurrence of
troubles and the troubles are removed accidentally along
with replacement of control unit, resulting in misjudgment
of cause. Therefore, before replacing the control unit,
check the connector joints and whether the unspecified
current flows in the control unit due to short-circuit
between harnesses.Trouble Intermittently Observed
Troubles intermittently observed are mostly attributable
to temporary imperfect connection of harnesses and
connectors.
When such troubles are found, check the associated
circuit according to the following procedure.
1. Check whether improper connectors are plugged in
or connector terminals are completely engaged.
2. Check whether the terminals are deformed or
damaged. If yes, remove the deformation or damage
and connect the terminals securely.
3. It is likely that wires in the harness are falsely broken.
Therefore, in examination of failed harness circuit,
shake the harness for check to such extent that the
harness will not be damaged.
Test Run of Filed TOD Vehicle
If the TOD indicator lamps experienced faulty operation
even once in the past, the failed portion can be identified
by use of the procedure ªDiagnosis from Trouble Codesº
or ªTrouble Diagnosis Depending on The Status of TOD
Indicatorº. If the troubles that are only recognized as
abnormal phenomena of the vehicle by the driver are
observed, conduct the test run in the following procedure
to reproduce the faulty phenomena and diagnose the fault
for each phenomenon.
1. Start the engine, and check that the TOD indicator
lamps are turned on for about two seconds for initial
check; the CHECK lamp goes off; and the TOD
indicator lamps display the specified drive mode. (If
the CHECK lamp starts blinking, read the trouble
codes and identify the failed portion.)
2. While keeping the vehicle standstill, operate the 4WD
switch and shift the transfer lever to change the
modes: 2H mode"TOD mode"4L mode"TOD
mode"2H mode. Check that the TOD indicator
lamps correctly display the status whenever the
mode is changed. If the transition status is displayed
during the shift operation, run the vehicle a little to
complete shifting.
3. Slowly start the vehicle in the TOD mode, and add the
power to accelerate to at least 40 km/h and maintain
the speed for about two minutes. Apply the brake to
completely stop the vehicle. Repeat this test pattern
at least three times.
4. Turn the steering to the right end (or left end) in the
TOD mode, and slowly start the vehicle and make a
circle five times. Next, conduct the same test in the 2H
mode.
5. Slowly start the vehicle in the TOD mode, and
accelerate to at least 40 km/h. Keep the established
speed, carefully change the mode in the sequence
ªTOD mode"2H mode "TOD modeº while checking
that the shift is complete in each mode change. After
the test, apply the brake to completely stop the
vehicle.
6. Slowly start the vehicle in the TOD mode, and
accelerate to at least 40 km/h. Apply the brake
strongly so that the ABS works, and completely stop
the vehicle.

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±26
Checking Failed TOD Control Unit Pin
NOTE:
1. Unplug the ECU connector and the pins, unless
otherwise specified.2. Before removing the ECU, turn off the ignition switch.
3. If the standard values are not observed, check the
pins with other testers.
Check
Pin
No.Circuit to be
testedIgnition
Switch
PositionEngine
StateMultimeter
Scale/
RangeMeasure
between Pin
NumberStandard ValveNote
14D-G MAPOFFSTOP
14, 19Continuity : OK
(Gasoline)
20P-GNDOFFSTOP
20, 19Continuity : OK
19GNDOFFSTOP
19, GNDContinuity : OK
84H SWOFFSTOP
8, 19No continuity (high,
4L) and continuity
(N) : OK
94L SWOFFSTOP
9, 19No continuity (high)
and continuity (4L,
N) : OK
10AXLE SWONRUN
10, 19Continuity : OKRemove ECU and start the engine. Move
the vehicle forth and back to connect axle
surely.
13DIAGOFFSTOP
13 (TOD), 8
(DLC Con-
nector)Continuity : OKDLC connector terminal 8
25IND.aONSTOPDCV25 (+), 19 (±)8.0 ~14.5 VLighting SW ON : 0V
Lighting SW OFF : 8.0 ~14.5 V
26IND.bONSTOPDCV26 (+), 19 (±)8.0 ~14.5 V
27IND.cONSTOPDCV27 (+), 19 (±)8.0 ~14.5 V
30CHECK
LAMPONSTOPDCV30 (+), 19 (±)8.0 ~14.5 V
11ABS INONSTOPDCV11 (+), 19 (±)11.5 ~14.5 V
15Ref.ONSTOPDCV15 (+), 19 (±)5 ~9 VConnect ECU
24Ft.(+)ONSTOPDCV24 (+), 19 (±)0.7 ~6 VConnect ECU (off one tooth of speed
sensor ring) and move the vehicle making
sure of voltage change.
23Rr.(+)ONSTOPDCV23 (+), 19 (±)0.7 ~6 VConnect ECU (off one tooth of speed
sensor ring) and move the vehicle making
sure of voltage change.
18COM(-)ONSTOPDCV18 (+), 19 (±)0VConnect ECU
1VigONSTOPDCV1 (+), 19 (±)8 ~14.5 V
7BRAKEOFFSTOPDCV7 (+), 19 (±)8 ~14.5 VPress brake pedal
21TPSONSTOPDCV21 (+), 19 (±)0.2 ~4.6 VStep on the accelerator pedal and make
sure that voltage changes.
34WD OUTOFFSTOP
3, 197 ~12 k
Disconnect battery GND terminal
5ADC(+)OFFSTOP
5, 1910 ~30
Disconnect battery GND terminal
4SOL(+)OFFSTOP
4, 191.0 ~5.0
Disconnect battery GND terminal
12TOD SWONSTOPDCV12 (+), 19 (±)SW OFF : 0 V
SW ON : 8.0 ~14.5 VSW OFF : Contact point open
SW ON : Contact point close
6LIGHTINGONSTOPDCV6 (+), 19 (±)SW OFF : 8.0 ~14.5
V
SW ON : 0 V
28AUTO INDIONSTOPDCV28 (+), 19 (±)TOD : 0 V
2H & 4L : 8.0 ~14.5
VLighting SW ON : 0V
Lighting SW OFF : 8.0 ~14.5 V
29RR INDIONSTOPDCV29 (+), 19 (±)0 V
17US/JAPOFFSTOP
17 (+), 19 (±)No continuity : OK

4D1±8
TRANSFER CASE (STANDARD TYPE)
Transfer Rear Oil Seal
Removal
1. Disconnect the rear propeller shaft from the transfer
case side.
2. Remove end nut and rear companion flange, using
the companion flange holder 5±8840±0133±0
(J±8614±11).
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3. Use the universal puller to remove the rear
companion flange and O±ring.
4. Remove the oil seal from the transfer case.
Installation
To install, follow the removal steps in the reverse order,
noting the following points:
1. Install oil seal and apply engine oil to the oil seal outer
surfaces.
2. Apply the recommended grease (BESCO L2) or
equivalent to the oil seal lip.
3. Use the oil seal installer 5±8840±2292±0 (J±39208)
to install the rear seal to the transfer rear case.
220RW105
4. Install the rear companion flange and O±ring.
5. Use the companion flange holder 5±8840±0133±0
(J±8614±11) to install a new end nut and tighten to the
specified torque.
Torque: 167 N´m (17.0kg´m/123 lb ft)
6. Use the punch 5±8840±2293±0 (J±39209) to stake
the end nut at two spots.
NOTE: Be sure to confirm that there is no crack at the
staked portion of the end nut after staking.
266RW027

TRANSFER CASE (STANDARD TYPE)
4D1±17
2. Remove the rear output shaft assembly (1) from the
transfer rear cover (with oil seal).
3. Remove ball bearing (8), using a bench press and the
bearing remover 5±8840±0015±0 (J±22912±01) .
226RW186
4. Remove the speedometer drive gear (7).
5. Remove the ball (6).
6. Remove the bearing snap ring (5), using a pair of snap
ring pliers.
7. Remove the ball bearing (4) from the rear output
shaft, using a bench press and the bearing remover
5±8840±0015±0 (J±22912±01).
226RW187
Inspection and Repair
Refer to ªTRANSFER CASE ASSEMBLYº in this section
for inspection and repair.
Reassembly
1. Install transfer rear cover (with oil seal).
Oil seal replacement

Remove the oil seal from the transfer rear cover.

Apply engine oil to the oil seal outer surfaces.

Fill in recommended grease (BESCO L2) or
equivalent in the oil seal lip.

Use the oil seal installer 5±8840±2292±0 (J±39208)
to install the rear oil seal to the transfer rear cover.
220RW104
2. Set the snap ring (3), and install ball bearing (4) to the
rear output shaft (2), using the ball bearing installer
5±8840±2159±0 (J±37223) and the adapter
5±8840±2192±1 (J±37486±A).
262RW068

4D1±24
TRANSFER CASE (STANDARD TYPE)
2. Remove the rear output shaft assembly (1) from the
transfer rear cover (with oil seal).
3. Remove ball bearing (8), using a bench press and the
bearing remover 5±8840±0015±0 (J±22912±01) .
226RW186
4. Remove the speedometer drive gear (7).
5. Remove the ball (6).
6. Remove the bearing snap ring (5), using a pair of snap
ring pliers.
7. Remove the ball bearing (4) from the rear output
shaft, using a bench press and the bearing remover
5±8840±0015±0 (J±22912±01).
226RW187
Inspection and Repair
Refer to ªTRANSFER CASE ASSEMBLYº in this section
for inspection and repair.
Reassembly
1. Install transfer rear cover (with oil seal).
Oil seal replacement

Remove the oil seal from the transfer rear cover.

Apply engine oil to the oil seal outer surfaces.

Fill in recommended grease (BESCO L2) or
equivalent in the oil seal lip.

Use the oil seal installer 5±8840±2292±0 (J±39208)
to install the rear oil seal to the transfer rear cover.
220RW104
2. Set the snap ring (3), and install ball bearing (4) to the
rear output shaft (2), using the ball bearing installer
5±8840±2159±0 (J±37223) and the adapter
5±8840±2192±1 (J±37486±A).
262RW068

TRANSFER CASE (STANDARD TYPE)
4D1±37
Reassembly
1. Put the transfer case (with oil seal) as the following
illustration.
Input shaft oil seal (1) replacement
1. Remove the oil seal from the transfer case.
2. Apply engine oil to the oil seal outer surfaces.
3. Apply recommended grease (BESCO L2) or
equivalent to the oil seal lip.
4. Use the oil seal installer 5±8840±2279±0
(J±38592) to install the oil seal to the transfer
case.
220RW106
Front output shaft oil seal (2) replacement
1. Remove the oil seal from the transfer case.
2. Apply engine oil to the oil seal outer surfaces.
3. Apply recommended grease (BESCO L2) or
equivalent to the oil seal lip.
4. Use the oil seal installer 5±8840±2281±0
(J±38594) to install the oil seal to the transfer
case.
220RW107
Legend
(2) Front output shaft oil seal
2. Apply chassis grease (3) to the sub±gear (23) and the
counter gear (22) thrust surfaces.
226RW134