ISUZU TROOPER 1998 Service Repair Manual

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±30
Diagnostic Trouble Codes
CodeItemDiagnosisCheck flow No.
12Start codeNormalÐ
13RefShorted GND6
14Front speed sensorInput abnormality (open, sig or com)2
15RefShorted VB6
16Front speed sensorInput abnormality3
21TPSShorted or disconnected wiring, abnormality in
input7
23ECUCPU abnormality1
24Rear speed sensorInput abnormality (open, sig or com)5
25CHECK lampShorted14
26EMC (+)Shorted GND10
27Rear speed sensorInput abnormality4
28ADC (+) & AXLE SWOutput abnormality11
31EMC (+)Shorted or disconnected coil/wiring9
32ADC (+)Shorted or disconnected coil/wiring12
33ADC (+)Shorted GND13
34D-G MAPInput abnormality8
35CHECK lampShorted or disconnected wiring14
36ECUCPU abnormality1
37ECUCPU abnormality1
38ECUCPU abnormality1
TPS : Throttle Position Sensor
EMC : Electromagnetic coil
ADC : Shift on the fly (Axle Dis Connect)
D-G MAP : Discrimination engine type

4B2±31 DRIVE LINE CONTROL SYSTEM (TOD)
Diagnosis from Trouble Codes

Diagnose the TOD based on the fault that has been
saved to the control unit according to the system
self-diagnostic function.
Check flow
Trouble codePhenomenonStandard
1 23, 36, 37, 38The ECU is failed.Ð
StepActionYe sNo
1Turn on the starter switch.
Is the trouble reproduced?Replace the ECU
and conduct the
test run.
Go to Step 3
Go to Step 2
21. Clear the trouble codes.
2. Conduct the test run.
Is the trouble reproduced during the test run?
Replace the ECU
and conduct the
test run.
Go to Step 3
The trouble is not
reproduced.
Refer to
ªTroubles
intermittently
observedº.
Go to Step 3
31. Check that all the parts are mounted.
2. Clear the trouble codes.
Is this step complete?
Repeat the
ªDiagnosis Flowº.
Return to Step 3

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±32
Check flowTrouble codePhenomenonStandard
214Front speed sensor signal open or
GND short, speed sensor com
open.0.3 > sensor voltage
NOTE: The following procedure shows the case that the
front or rear sensor reference or common grounding line
is broken.
D04RW061

4B2±33 DRIVE LINE CONTROL SYSTEM (TOD)
StepActionYe sNo
11. Start the engine.
2. Select 4H (TOD) mode.
Is the memory except DTC 14?
Go to Step 3Go to Step 2
2Is the continuity harness of terminal 24 (vehicle side terminal of
the front speed sensor)?Replace speed
sensor.
Go to Step 6
Repair the circuit.
Go to Step 6
3Is the memory DTC 24?
Go to Step 4
Refer to other
trouble check
flow.
Go to Step 2
4Is the continuity between harness of terminal 23 and 24 (vehicle
side terminal of the front and rear speed sensor)?
Go to Step 5
Repair the circuit.
Go to Step 6
5Is the continuity between harness of terminal 18 and 15 (vehicle
side terminal of the speed sensor COM and ref)?Replace front and
rear speed
sensor.
Go to Step 6
Repair the circuit.
Go to Step 6
61. Check that all the parts are mounted.
2. Clear the trouble code.
Is the step complete?
Repeat the
ªDiagnosis Flowº.
The trouble is not
reproduced.
Refer to
ªTroubles
intermittently
observedº.
Return to Step 6

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±34
Check flowTrouble codePhenomenonStandard
316The front speed sensor no pulse.Hi level : 4.5 ~ 6.0 V
Lo level : 0.7 ~ 2.0 V
Frequency (F) =
GAS: 832 Hz (at 50 km/h)
NOTE: Find the trouble in which the pulse corresponding
to the running speed is not input.
D04RW061

4B2±35 DRIVE LINE CONTROL SYSTEM (TOD)
StepActionYe sNo
11. Connect TECH 2.
While running in TOD mode, does TECH±2's front speed sensor
indication change with vehicle speed?
Go to Step 2
Repair and
inspection front
speed sensor
tone wheel.
Go to Step 4
2Is the continuity harness of terminal 24 (vehicle side terminal of
the front speed sensor)?Replace speed
sensor.
Go to Step 3
Repair the circuit.
Go to Step 3
31. Clear the trouble code.
While running at 40 kph in TOD mode for 30 consecutive sec, is
trouble code reissued?
Replace ECU.
Go to Step 4
Go to Step 4
41. Check that all the parts are mounted.
2. Clear the trouble code.
Is this step complete?
Repeat the
ªDiagnosis Flowº.
The trouble is not
reproduced.
Refer to
ªTroubles
intermittently
observedº.
Return to Step 4

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±36
Check flowTrouble codePhenomenonStandard
427The rear speed sensor no pulse.Hi level : 4.5 ~ 6.0 V
Lo level : 0.7 ~ 2.0 V
Frequency (F) =
832 Hz (at 50 km/h)
NOTE: Find the trouble in which the pulse corresponding
to the running speed is not input.
D04RW060

4B2±37 DRIVE LINE CONTROL SYSTEM (TOD)
StepActionYe sNo
11. Connect TECH 2.
While running in TOD mode, does TECH±2's rear speed sensor
indication change with vehicle speed?
Go to Step 2
Repair and
inspection rear
speed sensor
tone wheel.
Go to Step 4
2Is the continuity harness of terminal 23 (vehicle side terminal of
the rear speed sensor)?Replace speed
sensor.
Go to Step 3
Repair the circuit.
Go to Step 3
31. Clear the trouble code.
While running at 40 kph in TOD mode for 30 consecutive sec, is
trouble code reissued?
Replace EUC.
Go to Step 4
Go to Step 4
41. Check that all the parts are mounted.
2. Clear the trouble code.
Is this step complete?
Repeat the
ªDiagnosis Flowº.
The trouble is not
reproduced.
Refer to
ªTroubles
intermittently
observedº.
Return to Step 4

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±38
Check flowTrouble codePhenomenonStandard
524Rear speed sensor signal open or
GND short, speed sensor COM
open.0.3 > sensor voltage
NOTE: The following procedure shows the case that the
front or rear sensor reference or common grounding line
is broken.
D04RW061

4B2±39 DRIVE LINE CONTROL SYSTEM (TOD)
StepActionYe sNo
11. Start the engine.
2. Select 4H (TOD) mode.
Is the memory except DTC 24?
Go to Step 3Go to Step 2
2Is the continuity harness of terminal 23 (vehicle side terminal of
the rear speed sensor)?Replace speed
sensor.
Go to Step 6
Repair the circuit.
Go to Step 6
3Is the memory DTC 14?
Go to Step 4
Refer to other
trouble cheek
flow.
Go to Step 2
4Is the continuity between harness of terminal 23 and 24 (vehicle
side terminal of the front and rear speed sensor)?
Go to Step 5
Repair the circuit
Go to Step 6
5Is the continuity between harness of terminal 15 and 18 (vehicle
side terminal of the speed sensor COM and ref)?Replace front and
rear speed
sensor.
Go to Step 6
Repair the circuit.
Go to Step 6
61. Check that all the parts are mounted.
2. Clear the trouble code.
Is the step complete?
Repeat the
ªDiagnosis Flowº.
The trouble is not
reproduced.
Refer to
ªTroubles
intermittently
observedº.
Return to Step 6