2002 ISUZU AXIOM ECU

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.

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±68
Chart AIndicator drive circuit
Function of circuitThe circuit informs the indicator of the working condition of the ECU.
Fail conditionAll the TOD indicator lamps and CHECK lamp are lit.
Indicator lamp stateÐ
TOD switch position2H/TOD/4LÐ
D04R200023

4B2±69
DRIVE LINE CONTROL SYSTEM (TOD)
StepActionYe sNo
1Turn on the starter switch.
Is the battery voltage observed between terminals 14 and 47?The ECU has
failed. Replace
the ECU.
Go to
Step 2
Check the battery
circuit.
Go to
Step 2
2Check that all the parts are mounted.
Is this step complete?Repeat the
ªDiagnosis Flowº.
Return to Step 2

4B2±75
DRIVE LINE CONTROL SYSTEM (TOD)
StepActionYe sNo
11. Turn off the starter switch.
2. Disconnect the ECU connector (C±38).
Is the continuity established between the connector terminals
(C±38) 14 and (C±38) 7?
Go to Step 2
Replace TOD
indicator lamp
bulb.
Go to
Step 6
2Is the continuity established between the connector terminals
(C±38) 14 and (C±38) 19?
Go to Step 3
Replace TOD
indicator lamp
bulb.
Go to
Step 6
31. Turn off the starter switch and connect the ECU connector.
2. Turn on the starter switch.
When the TOD switch is selected to the TOD position, is 0V
observed between terminals 30 and 47, and 43 and 47? Does the
voltage between the terminals 7 and 47, 19 and 47, and 8 and 47
comply with the TOD mode in the following table?
Go to Step 4
Repair the TOD
switch circuit.
Go to
Step 6
4When the TOD switch is selected to the 2H position, is 12V
observed between terminals 30 and 47, and 0V observed
between terminals 43 and 47? Does the voltage between the
terminals 7 and 47, 19 and 47, and 8 and 47 comply with the 2H
mode in the following table?
Go to Step 5
Repair the TOD
switch circuit.
Go to
Step 6
5When the TOD switch is selected to the 4L position, is 0V
observed between the terminal 30 and 47 and 12V observed
between the terminal 43 and 47? Does the voltage between the
terminals 7 and 47, 19 and 47, and 8 and 47 comply with the 4L
mode in the following table?The phenomenon
is not
reproduced.
Refer to
ªTrouble
intermittently
observedº.Repair the TOD
switch circuit.
Go to
Step 6
61. Check that all the parts are mounted.
Is this step complete?
Verify repair.Go to Step 6
Table: Indicator terminal voltage
Unit: V
TOD
switch
Terminals measured
switch
modeFront 7
and 47AUTO 19
and 47Rear 8 and
47
2H8.0 ~ 14.58.0 ~ 14.50
TOD000
4L08.0 ~ 14.50

4B2±81
DRIVE LINE CONTROL SYSTEM (TOD)

StepActionYe sNo
11. Turn off the starter switch.
2. Disconnect the ECU connector (C±38).
Is the continuity established between the connector terminals
(C±38) 14 and (C±38) 19?
Go to Step 2
Replace TOD
indicator lamp
bulb.
Go to
Step 5
21. Turn off the starter switch and connect the ECU connector.
2. Turn on the starter switch.
When the TOD switch is selected to the TOD position, is 0V
observed between terminals 30 and 47, and 43 and 47? Does the
voltage between the terminals 7 and 47, 19 and 47, and 8 and 47
comply with the TOD mode in the following table?
Go to Step 3
Repair the TOD
switch circuit.
Go to
Step 5
3When the TOD switch is selected to the 2H position, is 12V
observed between terminals 30 and 47, and 0V observed
between terminals 43 and 47? Does the voltage between the
terminals 7 and 47, 19 and 47, and 8 and 47 comply with the 2H
mode in the following table?
Go to Step 4
Repair the TOD
switch circuit.
Go to
Step 5
4When the TOD switch is selected to the 4L position, is 0V
observed between the terminal 30 and 47 and 12V observed
between the terminal 43 and 47? Does the voltage between the
terminals 7 and 47, 19 and 47, and 8 and 47 comply with the 4L
mode in the following table?The phenomenon
is not
reproduced.
Refer to
ªTrouble
intermittently
observedº.Repair the TOD
switch circuit.
Go to
Step 5
51. Check that all the parts are mounted.
Is this step complete?
Verify repair.Go to Step 5
Table: Indicator terminal voltage
Unit: V
TOD
switch
Terminals measured
switch
modeFront 7
and 47AUTO 19
and 47Rear 8 and
47
2H8.0 ~ 14.58.0 ~ 14.50
TOD000
4L08.0 ~ 14.50

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±84
StepActionYe sNo
11. Turn on the starter switch.
2. The car stops, the AT selector is N position and the brake is
applied.
When the TOD switch is changed to the TOD position, is 12V
observed between terminals 31 and 47 (4H switch)?
Go to Step 2Go to Step 9
21. The car stops the AT selector is N position and the brake is
applied.
When the TOD switch is changed to the 4L position, is 12V
observed between terminals 31 and 47 (4H switch)?
Go to Step 3Go to Step 9
31. Turn off the starter switch.
Is there the continuity terminal 14 and 7?
Go to Step 4
Replace the TOD
indicator lamp
bulb, or repair the
circuit.
Go to
Step 13
4Is there the continuity between the terminals 14 and 19?
Go to Step 5
Replace the TOD
indicator lamp
bulb, or repair the
circuit.
Go to
Step 13
5Is there the continuity between the terminal 14 and 8?
Go to Step 6
Replace the TOD
indicator lamp
bulb, or repair the
circuit.
Go to
Step 13
61. Turn on the starter switch.
2. The car stops the AT selector is N position and the brake is
applied.
When the TOD switch is changed to the 4L position, is 0V
observed between terminal 7 and 47? (for 2 seconds after the
starter switch ON) ?
Go to Step 7
The ECU has
frailed. Replace
the ECU.
Go to
Step13
7Is 0V observed between terminal 19 and 47? (for 2 seconds after
the starter switch ON)
Go to Step 8
The ECU has
failed. Replace
the ECU.
Go to
Step 13
8Is 0V observed between terminal 8 and 47? (for 2 seconds after
the starter switch ON)The phenomenon
is not
reproduced.
Refer to
ªTrouble
intermittently
observedº.
The ECU has
failed. Replace
the ECU.
Go to
Step 13
91. The car stops, the AT selector is N position, and the brake is
applied.
2. The TOD switch is changed to the TOD (or 2H) position.
3. Turn off the starter switch.
4. Disconnect the ECU connector (C±37).
Is there the continuity between the connector (C±37) terminal 9
and 25?
Go to Step 11Go to Step 10