check engine ISUZU AXIOM 2002 Service Owner's Guide

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±46
StepActionYe sNo
11. Start the engine.
Does the voltage between terminals 12 and 47 meet the standard
5V?Refer to ªTrouble
intermittently
observedº.
Go to Step 2
2Is the voltage below the standard?Go to Step 3Go to Step 7
31. Turn off the starter switch.
2. Disconnect the ECU connector.
Is the continuity established between vehicle harness terminals
(C±38)12 and (C±37)25?
Go to Step 4
The ECU is
failed. Replace
the ECU.
Go to
Step 8
41. Disconnect the H-7 connector.
Is the continuity established between floor harness connector
terminals (H-7)2 and (H-7)15?
Go to Step 5
Short to GND
between
(C±38)12 and
(H±7)2.
Repair the circuit.
Go to
Step 8
51. Disconnect the A-1 connector.
Is the continuity established between transfer harness connector
male terminals (A±1)1 and (A±1)7?
Replace the rear
speed sensor.
Go to
Step 8
The reference
harness for the
rear speed
sensor is
short±circuited to
GND. Repair the
circuit.
Go to
Step 6
61. Disconnect the A-1 connector.
Is the continuity established between transfer harness connector
terminals (A±1)2 and (A±1)7?
Replace the front
speed sensor.
Go to
Step 8
The reference
harness for the
rear speed
sensor is
short±circuited to
GND. Repair the
circuit.
Go to
Step 8
71. Turn off the starter switch.
2. Disconnect the ECU connector.
3. Turn on the starter switch.
Is the battery voltage observed between harness connector
terminals (C±38)12 and (C±37)25?
Repair the circuit.
Go to
Step 8
The ECU has
failed. Replace
the ECU.
Go to
Step 8
81. Check that all the parts are mounted.
2. Clear the trouble code.
Is this step complete?
Repeat the
ªDiagnosis Flowº
Go to Step 8

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±54
StepActionYe sNo
11. Clear the trouble code.
2. Start the engine
3. Set the TOD mode.
Is there DTC31 (P1721)?
Go to Step 2
Refer to ªTrouble
intermittently
observedº.
21. Turn off the starter switch.
2. Disconnect the ECU connector from ECU.
Is the continuity established between terminals (C±38)11 and
(C±38)22?
Go to Step 3Go to Step 5
31. Connect the ECU connector.
2. Start the engine.
3. Set the TOD mode.
Does the voltage between terminals 11 and 22 indicate at least
0.4V?
Go to Step 4Go to Step 6
4Is the battery voltage always observed between terminals 11 and
22?The harness is
short±circuited on
the battery.
Repair the circuit.
Go to
Step 8Go to Step 6
51. Disconnect the A±1 connector.
Is the continuity established between transfer connector
terminals (A±1)8 and (A±1)7?
The harness is
broken. Repair
the circuit.
Go to
Step 8
Replace the
transfer
electromagnetic
coil (solenoid
clutch).
Go to
Step 8
61. Turn off the starter switch.
2. Disconnect the ECU connector from ECU.
Is the resistance between the connector (C±38) terminal 11 and
22 1.0 ~ 5.0
?The ECU has
failed. Replace
the ECU
Go to
Step 8Go to Step 7
7Is the resistance between the transfer connector (A±1) terminal 8
and 7 1.0 ~ 5.0
?
The harness is
disconnection or
short to GND.
Repair the circuit.
Go to
Step 8
Replace the
transfer
electromagnetic
coil (solenoid
clutch).
Go to
Step 8
81. Check that all the parts are mounted.
2. Clear the trouble code.
Is this step complete?
Repeat the
ªDiagnosis Flowº.
Return to Step 8

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±62
StepActionYe sNo
11. Turn on the starter switch.
When the motor is not moving, is the voltage between the
terminals 35 and 47 8.0 ~ 14.5V?
Go to Step 2Go to Step 3
2When the motor is not moving, is the voltage between the terminal
48 and 47 8.0 ~ 14.5V?
Go to Step 5Go to Step 3
31. Turn off the starter switch.
2. Disconnect the ECU connector (C±37) and transfer connector
(A±2).
Is there the continuity between the connector terminal (C±37) 13
and (A±2) 7?
Go to Step 4
Repair the circuit.
Go to
Step 11
4Is there the continuity between the connector terminal (C±37) 26
and (A±2) 4?
Go to Step 5
Repair the circuit
Go to
Step 11
51. Connect the ECU connector (C±37) and transfer connector
(A±2).
2. Turn on the starter switch
Is the transfer shifted to the low range from the high range?
Go to Step 6Go to Step 7
61. Is the transfer shifted to the high range from the low range.The phenomenon
is not
reproduced.
Refer to
ªTrouble
intermittently
observedº.
Go to Step 8
71. After the starter switch is turned off, turn on the starter switch.
2. Right after the TOD switch is changed to the 4L position from
the TOD position, measure the voltage for 5 seconds.
Is the voltage between terminal 48 and 47 0V while the motor is
moving and 8.0 ~ 14.5V after the motor moving stops?
Go to Step 9
Replace the
ECU.
Go to
Step 11
81. After the starter switch is turned off, turn on the starter switch.
2. Right after the TOD switch is changed to the TOD position
from 4L position, measure the voltage for 5 seconds.
Is the voltage between terminals 35 and 47 0V while motor is
moving and 8.0 ~14.5V after the motor moving stops?
Go to Step 9
Replace the
ECU.
Go to
Step 11
91. Remove the motor asm with the connector (A±2) from the
transfer.
2. Connect the ECU connector (C±37).
3. Turn on the starter switch.
When the TOD switch is changed to the 4L position from the TOD
position, does the shaft in the motor asm rotate to the Low
direction?
Go to Step 10
Replace the
high-low motor
asm.
Go to
Step 11
10When the TOD switch is changed to the TOD position from the 4L
position, does the shaft in the motor asm rotate to the High
direction?
Repair the
transfer asm.
Go to
Step 11
Replace the
high±low motor
asm.
Go to
Step 11
111. Check that all the parts are mounted.
2. Clear the trouble code.
Is this step complete?
Verify the repairReturn to Step 11
NOTE:

Confirm the operation conditions when changing high
and low range.
± The car stops. (less than 2 km/h or 1.2 mph and
engine speed less than 1500 rpm)± The AT selector position is neutral.
± The brake is applied (brake switch: ON)

Verify the completion of changing the high/low range
by the TOD indicator on the instrument panel.

4B2±63
DRIVE LINE CONTROL SYSTEM (TOD)
Check flowTrouble codePhenomenonStandard
1442 (P1773)Error operation was carried out
under high±low motor running.Ð
StepActionYe sNo
11. Clear the trouble code.
Is the transfer changed to the low range from the high range?
Go to Step 2Go to Step 3
2Is the transfer changed to the high range from the low range?The phenomenon
is not
reproduced.
Refer to
ªTrouble
intermittently
observedº.
Go to Step 3
3Is the trouble code memoried?
Go to Step 4
See ªDiagnosis
from Symptomº.
4Is the memory DTC42 (P1773)?
Go to Step 5
Remove the
trouble
associated with
codes except
DTC 42 first.
Confirm the DTC
again.
Go to
Step 5
51. Clear the trouble code.
2. Confirm the condition and operation of the transfer range
changing and check the state of the TOD indicator. Change
the transfer to the low from the high and vice versa.
Is the transfer changed to the low from the high and to the high
from the low?The transfer is
changed in both
ranges by the
correct operation.
Operate the
transfer
according to
ªOwner's
Manualº.
Go to Step 6
6Is the trouble code memoried?
Go to Step 7
See ªDiagnosis
from Symptomº.
7Is the memory DTC 42 (P1773)?
Replace the
ECU.
Go to
Step 8
Remove the
trouble
associated with
codes except
DTC 42 first.
Confirm the DTC
again.
Go to
Step 5
81. Check that all the parts are mounted.
2. Clear the trouble code.
Is this step complete?
Verify the repair.Go to Step 8
NOTE:

Confirm the operation conditions when changing
high/low range.
± The car stops. (less than 2 km/h or 1.2 mph and
engine speed: less than 1500 rpm)
± The AT selector position is neutral.
± The brake is applied (brake switch: ON)
Verify the completion of changing the high/low range
by the TOD indicator on the instrument panel.

This code does not indicate the trouble of the transfer
or ECU, and is memoried when an error operation is
carried out under high-low motor running.
Therefore this code is not memoried if the transfer is
operated according to
ªOwner's Manualº.

4B2±65
DRIVE LINE CONTROL SYSTEM (TOD)
StepActionYe sNo
11. Turn on the starter switch.
Is the transfer changed to the low range from the high range?
Go to Step 2Go to Step 4
2Is the transfer changed to the high range from the low range?Go to Step 3Go to Step 5
31. Clear the trouble code.
2. Turn on the starter switch.
Is the memory DTC 55 (P1755)?
Go to Step 1
The phenomenon
is not
reproduced.
Refer to
ªTrouble
intermittently
observedº.
41. Turn off the starter switch.
2. Disconnect the ECU connector (C±37).
Is the continuity between the terminals ranged within the any case
(case1, 2 or 3) in the following table (1)?
Go to Step 8Go to Step 6
51. Turn off the starter switch.
2. Disconnect the ECU connector (C±37).
Does the continuity between the terminals comply with the
following table (2)?
Go to Step 8Go to Step 7
61. Turn off the starter switch.
2. Disconnect the transfer connector (A±2).
Is the continuity between the male terminals ranged within the any
case (case1, 2 or 3) in the following table (3)?
Go to Step 8
The encoder has
failed. Replace
the high-low
motor asm.
Go to
Step 9
71. Turn off the starter switch.
2. Disconnect the transfer connector (A-2).
Does the continuity between male terminals comply with the
following table (4)?
Go to Step 8
The encoder has
failed. Replace
the high-low
motor asm.
Go to
Step 9
81. Turn off the starter switch.
2. Disconnect the ECU connector (C±37) and transfer connector
(A±2).
Is there the continuity between connector terminal (C±37) 4 and
(A±2) 6, (C±37) 17 and (A±2) 1, (C±37) 3 and (A±2) 2, (C±37) 16
and (A±2) 3, and (C±37) 2 and (A±2) 5?
The encoder has
failed. Replace
the high-low
motor asm.
Go to
Step 9
The circuit in
which there is no
continuity is
broken. Repair
the circuit.
Go to
Step 9
91. Check that all the parts are mounted.
2. Clear the trouble code.
Is this step complete?
Verify the repair.Go to Step 9
NOTE:

Confirm the operation conditions when changing high
and low range.
± The car stops. (less than 2 km/h or 1.2 mph and
engine speed: less than 1500 rpm)
± The AT selector position is neutral.
± The brake is applied (brake switch: ON)

Verify the completion of changing the high/low range
by the TOD indicator on the instrument panel.

When changing high/low range, start the engine to
prevent the battery dead.

4B2±95
DRIVE LINE CONTROL SYSTEM (TOD)
StepActionYe sNo
1Start the engine.
When the TOD switch is selected to the TOD position, is 0V
observed between terminals 42 and 47?
Go to Step 2Go to Step 4
21. The car stops, the AT selector is N position, and the brake is
applied.
2. Select the TOD switch to the 4L position.
Is 0V observed between terminals 42 and 47?
Go to Step 3Go to Step 4
31. The car stops, the AT selector is N position, and the brake is
applied.
When the TOD switch is selected to the 4L position, is 12V
observed between the terminal 19 and 47?The phenomenon
is not
reproduced.
Refer to
ªTroubles
intermittently
observedº.
The ECU has
failed.Replace
the ECU.
Go to
Step 8
41. The car stops, the AT selector is N position, and the brake is
applied.
When the TOD switch is selected to the 2H position, is the battery
voltage observed between the terminal 23 and 47.
Go to Step 5Go to Step 7
5When the TOD switch is selected to the TOD position (TOD
mode), is 0 ~ 1V observed between terminals 23 and 47?
Go to Step 6Go to Step 7
61. The car stops, the AT selector is N position, and the brake is
applied.
When the TOD switch is selected to the 4L position, is 0V
observed between terminals 23 and 47?Repair the circuit
or check the
ªFront Axle
Disconnectº.
(Refer to
section
4B
)
Go to
Step 8Go to Step 7
7Is any of the trouble codes 28 (P1760), 32 (P1761) and 33
(P1762) recorded?Examine the
trouble based on
ªDiagnosis from
Trouble Codesº.The ECU has
failed. Replace
the ECU.
Go to
Step 8
8Check that all the parts are mounted.
Is this step complete?
Verify the repair.Go to Step 8

4B2±97
DRIVE LINE CONTROL SYSTEM (TOD)
StepActionYe sNo
1Start the engine.
When the TOD switch is selected to the TOD position, is 0V
observed between terminals 42 and 47?
Go to Step 2Go to Step 6
21. The car stops, the AT selector is N position, and the brake is
applied.
When the TOD switch is selected to the 4L position, is 0V
observed between terminals 42 and 47?
Go to Step 3Go to Step 6
31. The car stops, the AT selector is N position, and the brake is
applied.
2. Select the TOD switch to the 2H position.
Is 5V observed between terminals 42 and 47?
Go to Step 4Go to Sep 6
4Is 12V observed between terminals 7 and 47?
Go to Step 5
Replace the
ECU.
Go to
Step 10
5Is 12V observed between terminals 19 and 47?The phenomenon
is not
reproduced.
Refer to
ªTroubles
intermittently
observedº.
The ECU has
failed.Replace
the ECU.
Go to
Step 10
61. The car stops, the AT selector is N position, and the brake is
applied.
When the TOD switch is selected to the 2H position, is the battery
voltage observed between terminals 23 and 47?
Go to Step 7Go to Step 9
71. The car stops, the AT selector is N position, and the brake is
applied.
When the TOD switch is selected to the TOD position, is 0V
observed between terminals 23 and 47?
Go to Step 8Go to Step 9
81. The car stops, the AT selector is N position, and the brake is
applied.
When the TOD switch is selected to the 4L position, is 0V
observed between terminals 23 and 47?Repair the circuit
or check the
ªFront Axle
Disconnectº.
(Refer to
section
4B
)
Go to
Step 10Go to Step 9
9Is any of the trouble codes 28 (P1760), 32 (P1761) and 33
(P1762) recorded?Examine the
trouble based on
ªDiagnosis from
Trouble Codesº.The ECU has
failed. Replace
the ECU.
Go to
Step 10
10Check that all the parts are mounted.
Is this step complete?
Verify the repair.Go to Step 10

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±102
Diagnosis from Symptom
Troubles that are not indicated by the warning lamp are
listed in the table below. These troubles are caused by the
faults that cannot be detected by the self-diagnostic
function of the control unit.
If this type of trouble is observed, interview the customer
and conduct test runs to reproduce the trouble,
cross-check the reported trouble with the listed
phenomena, and diagnose and analyze the trouble on the
item by item basis.
PhenomenaMajor causeCorrective action
1The tight corner braking is
observed when the vehicle is
subject to full steering.
The standard tires are not used.

The tire pressure is incorrect.

The tires are worn inuniformity.

The transfer or wiring is
imperfect.

The limited slip differential is
failed.Check and recondition the
vehicle according to Chart 1.
2Even if the TOD switch is selected
to the TOD position, the F4WD
mode is not active, resulting in
remarkable rear wheel spin.
The transfer or wiring is
imperfect.

The shift on the fly system is
failed.Check and recondition the
vehicle according to Chart 2.
3
When the TOD switch is
selected to the TOD position,
the drive resistance of the
F4WD system is too large to get
sufficient running speed.

Noised drive line.
The standard tires are not used.

The tires are worn inuniformity.

The transfer or wiring is
imperfect.

The limited slip differential is
failed. Check and recondition the
vehicle according to Chart 1.
4The shift on the fly system (front
axle disconnect) generates gear
noises.
The wiring is imperfect.

The shift on the fly system is
failed.Check and recondition the
vehicle according to Chart 3.
5The braking distance gets long
even when the ABS is active.
The wiring is imperfect.

The ABS is failed.Check and recondition the
vehicle according to Chart 4.
6The transfer does not change to the
low range from the high range.
The transfer or wiring is
imperfect.

The TOD switch is imperfect.

The AT inhibitor switch is
imperfect.
Check and recondition the
vehicle according to chart 5.
7The transfer does not change to the
high range from the low range.
im erfect.

The brake switch is imperfect.

The engine speed signal is
imperfect.

The speed sensor is imperfect.
Check and recondition the
vehicle according to chart 6.
8The transfer stays neutral and the
vehicle does not run.
The transfer is imperfect.Check and recondition the
vehicle according to chart 7.

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±104
StepActionYe sNo
1Are the front and rear tires in specified size?
Go to Step 2
Replace the tires
with specified
ones, and service
the new tires.
Go to
Step 16
2Is the tire pressure correct?
Go to Step 3
Inflate the tires
with specified
pressure.
Go to
Step 16
3Are the tires free from abnormal wear?
Go to Step 4
Replace the tires
with specified
ones, and service
the new tires.
Go to
Step 16
4Are different types of tires used?
Go to Step 5
Replace the tires
with specified
ones, and service
the new tires.
Go to
Step 16
51. Start the engine.
2. Select the TOD switch to the TOD position.
3. Fully turn the steering to the left (or right) end, and select the D
range and start the creep run.
Does the tight corner braking occur? Is the judder with chug-chug
sound observed? * Use caution on the operation.
Go to Step 6 Go to Step 11
61. Select the TOD switch to the 2H position.
2. Fully turn the steering to the left (or right) end, and select the D
range and start the creep run.
Does the tight corner braking occur? Is the judder with chug-chug
sound observed? * Use caution on the operation.
Go to Step 7 Go to Step 14
7Is an LSD mounted to the rear differential? Go to Step 8 Go to Step 9
8Is the genuine LSD oil used in the rear differential?
Go to Step 9
Replace the
differential oil.
Go to
Step 16
9Does the engine output the power correctly?
Go to Step 10
Check the
engine.
Go to
Step 16
10Do the speed sensors work correctly? (Check trouble codes.)The ECU has
failed. Replace
the ECU.
Go to
Step 16
Replace the
speed sensors.
Go to
Step 16
11Is the tight corner braking observed only when the brake is
applied?
Go to Step 12
Conduct full
steering under
WOT.
Go to
Step 5
121. Turn on the starter switch.
Is 8 ~ 10 V observed between terminals 33 and 47?
Go to Step 13
Repair the circuit
of the ECU
connector
terminal 33 (ABS
IN).
Go to
Step 16

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±114
StepNo Ye s Action
121. Start the engine.
Is the engine pulse signal between terminal 2 and 47 at engine
speed under 1500 rpm within the standard? Standard: less than
4500 Hz
Replace the
ECU.
Go to
Step 13
The engine pulse
signal is
abnormal. Repair
or replace the
PCM.
Go to
Step 13
13Check that all the parts are mounted.
Is this step complete?
Verify the repair.Go to Step 13
Continuity between terminal in 4L position
(Table: continuity)
Terminals
No.
26 and
2439 and
2425 and
2438 and
24
Continuity
of 4L
positionYESNOYESYES or
NO
Standard (Table: voltage)
Unit: V
Terminals28 and 4741 and 4727 and 47
Voltage0120