2002 ISUZU AXIOM stop start

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±14
Diagnosis
General Information Diagnosis
The troubles on TOD are classified into the group that can
be identified by the lighting status of the TOD indicator
lamps and those that can be recognized as abnormal
phenomena of the vehicle by the driver.
The troubles that can be identified by the lighting status of
the TOD indicator lamps are examined by the procedures
ªDiagnosis from Trouble Codesº and ªTrouble Diagnosis
Depending on The Status of TOD Indicatorº. The troubles
that can be recognized as abnormal phenomena of the
vehicle by the driver are examined by the procedure
ªDiagnosis from symptomº.
Self-diagnosis
The control unit has a function of self-diagnosis. If a
trouble occurs in the course of system startup, the control
unit blinks the CHECK lamp and saves the trouble code.
C07RW021
NOTE: If an intermittent fault occurs, the control unit
stops blinking upon removal of the fault. The trouble code
is saved to the control unit.

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±16
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. Short-circuit terminal 8 of the self-diagnostic
connector to GND (terminal 4 or 5).
2. Turn on the starter switch while maintaining the state
of step1, and stop short-circuiting terminal 8 to GND
within five seconds.
826R200011
3. If the conditions shown in steps 1 and 2 are met, the
trouble codes saved to the control unit are cleared.
(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 (i.e. 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 Failed 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 TOD
switch 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 (25 mph)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 (25 mph). 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 (25 mph). Apply the
brake strongly so that the ABS works, and completely
stop the vehicle.
7. Slowly start the vehicle in the 4L mode, and
accelerate to at least 20 km/h (13 mph). Apply the
brake to completely stop the vehicle.
If the CHECK lamp starts blinking during the test run, read
the trouble codes and give appropriate maintenance
according to the diagnostic procedure. If the TOD
indicator lamps are lit abnormally during the run, check
the lighting condition and give appropriate maintenance
according to the diagnostic procedure. Even if the
phenomena are not observed, try to reproduce the
abnormal state reported by the customer to the possible
extent.

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±30
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
StateUnit
Scale/
RangeMeasure
between
Pin No.Standard ValueNote
22P-GNDOFFSTOP
22, 47Continuity : OK
46GNDIOFFSTOP
46, 47Continuity : OK
47GND 2OFFSTOP
47, GNDContinuity : OK
314H SWOFFSTOP
31, 47No continuity
(high, 4L) : OK
444L SWOFFSTOP
44, 47No continuity
(high) and
continuity (4L) :
OK
42AXLE SWONRUN
42, 47Continuity(TOD,
4L) : OKRemove ECU connector and start
the engine. Move the vehicle forth
and back to connect axle surely.
29DIAGOFFSTOP
29 (TOD),
8 (DLC
Connec-
tor)Continuity : OKDLC connector terminal 8
7IND.AONSTOPDCV7 (+), 47
(±)8.0 ~14.5 Vwhen the indicator lamp is turned
off.
20CHECK
TODONSTOPDCV20 (+), 47
(±)8.0 ~14.5 VWhen the indicator lamp is turned
off.
33ABS INONSTOPDCV33 (+), 47
(±)6.0 ~11.0 V
12REFONSTOPDCV12 (+), 47
(±)5 ~9 VConnect ECU
32FRT.(+)ONSTOPDCV32 (+), 47
(±)0.7 ~6 VConnect ECU and move the
vehicle (off one tooth of speed
sensor ring) making sure of
voltage change.
45RR.(+)ONSTOPDCV45 (+), 47
(±)0.7 ~6 VConnect ECU and move the
vehicle (off one tooth of speed
sensor ring) making sure of
voltage change.
13COM(-)ONSTOPDCV13 (+), 47
(±)0VConnect ECU
14VIGONSTOPDCV14 (+), 47
(±)8 ~14.5 V
34VBOFFSTOPDCV34 (+), 47
(±)8.0 ~14.5 V
37BRAKE
SWOFFSTOPDCV37 (+), 47
(±)8 ~14.5 VPress brake pedal
15TPSONSTOPDCV15 (+), 47
(±)PWM duty cycle
10%(MAX) ± 90
%(MIN)Step on the accelerator pedal and
make sure that duty cycle
changes.

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±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±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

4B2±85
DRIVE LINE CONTROL SYSTEM (TOD)
StepNo Ye s Action
101. Connect the ECU connector (C±37) and turn on the starter
switch.
2. The car stops, the AT selector is N position, and the brake is
applied.
3. Change the TOD switch to the 4L position.
4. Turn off the starter switch and disconnect the ECU connector
(C±37).
Is there the continuity between the connector (C±37) terminal 9
and 25?
Go to Step 11
The ECU has
failed. Replace
the ECU.
Go to
Step 13
111. Disconnect the connector (H±7).
Is the continuity established between the transfer connector
terminals (H±7)4 and (C±37) 9?
Go to Step 12
The harness is
broken between
terminal (H±7) 4
and (C±37) 9.
Repair the circuit.
Go to
Step 13
121. Connect the connector (H±7).
2. Disconnect the connector (A±1).
Is there the continuity between the connector terminal (A±1) 4 and
(C±37) 9?
Repair the
transfer.
Go to
Step 13
The harness
between the
connector
terminal (C±37) 9
and (A±1) 4 is
short-circuited to
GND. Repair the
circuit.
Go to
Step 13
13Check that all the parts are mounted.
Is this step complete?
Verify the repair.Return to Step 13

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±88
StepActionYe sNo
11. Turn on the starter switch.
2. The car stops, the AT selector is the N position, and the brake
is applied.
When the TOD switch is changed to the TOD (or 2H) position, is
12V observed between terminals 44 and 47 (4L switch)?
Go to Step 2Go to Step 4
21. The car stops, the AT selector is the N position, and the brake
is applied.
When the TOD switch is changed to the 4L position, does the
transfer become the 4L state?
Go to Step 3
Refer to
ªDiagnosis from
symptomº.
3Is 0V observed between the terminal 44 and 47?The ECU has
failed.Replace
the ECU.
Go to
Step 10Go to Step 10
41. The car stops, the AT selector is the N position, and the brake
is applied.
When the TOD switch is changed to the TOD (or 2H) position, is
12V observed between the connector (C±37) terminal 22 and 25?
Go to Step 5Go to Step 6
51. Turn off the starter switch and connect the EUC connector.
2. The car stops, the AT selector is the N position, and the brake
is applied.
When the TOD switch is changed to the 4L position, is 0V
observed between terminals (C±37) 22 and (C±37) 25 (4L
switch)?The phenomenon
is not
reproduced.
Refer to
ªTrouble
intermittently
observedº.
Go to Step 6
61. Turn off the starter switch and connect ECU connector.
2. Turn on the starter switch.
3. The car stops, the AT selector is the N position, and the brake
is applied.
4. Change the TOD switch to the TOD (or 2H) position.
5. After the transfer has changed to the TOD (or 2H) mode, turn
off the starter switch and disconnect the ECU connector
(C±37).
Is there the continuity between the connector (C±37) terminal 22
and 25?
Go to Step 9Go to Step 7
71. Turn off the starter switch and connect the ECU connector.
2. Turn on the starter switch.
3. The car stops, the AT selector is the N position, and the brake
is applied.
4. Change the TOD switch to the 4L position.
5. After the transfer has changed to the 4L mode, turn off the
starter switch.
6. Disconnect the ECU connector.
Is there the continuity between the connector (C±37) terminal 22
and 25?
The phenomenon
is not
reproduced.
Refer to
ªTrouble
intermittently
observedº.
Go to Step 8
81. Turn off the starter switch and connect the ECU connector.
2. Turn on the starter switch.
3. The car stops, the AT selector is the N position, and the brake
is applied.
4. Change the TOD switch to the TOD (or 2H) position.
5. After the transfer has changed to the TOD (or 2H) mode, turn
off the starter switch.
6. Disconnect the transfer connector (A±1).
Is there the continuity between the connector terminal (A±1) 12
and GND?
Repair the
transfer.
Go to
Step 10
Repair the circuit
between (C±37)
22 and (A±1) 12.
Go to
Step 10