Page 409 of 2100

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-GNDOFFSTOP22, 47Continuity : OK
46GNDIOFFSTOP46, 47Continuity : OK
47GND 2OFFSTOP47, GNDContinuity : OK
314H SWOFFSTOP31, 47No continuity
(high, 4L) : OK
444L SWOFFSTOP44, 47No continuity
(high) and
continuity (4L) :
OK
42AXLE SWONRUN42, 47Continuity(TOD,
4L) : OKRemove ECU connector and start
the engine. Move the vehicle forth
and back to connect axle surely.
29DIAGOFFSTOP29 (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.
Page 410 of 2100
4B2±31
DRIVE LINE CONTROL SYSTEM (TOD)
Check
Pin
No.Note Standard Value Measure
between
Pin No. Unit
Scale/
Range Engine
State Ignition
Switch
Position Circuit to be
tested
364WD
OUTOFFSTOP36, 477 ~12 kDisconnect battery GND terminal
11EMC(+)OFFSTOP11, 221.0 ~5.0 Disconnect battery GND terminal
30TOD SW
AONSTOPDCV30 (+), 47
(±)SW: TOD, 4L: 0
V
SW:2H:8.0 ~
14.5 V
43TOD
SWBONSTOPDCV43 (+), 47
(±)SW: 2H,
TOD:0V
SW: 4L: 8.0 ~
14.5V
40LIGHTONSTOPDCV40 (+), 47
(±)SW OFF : 0 V
SW ON : 8.0 ~
14.5 V
19IND BONSTOPDCV19 (+), 47
(±)8.0 ~14.5 VWhen the indicator lamp is turned
off
8IND CONSTOPDCV8 (+), 47
(±)8.0 ~ 14.5 VWhen the indicator lamp is turned
off
27AT POSCONSTOPDCV27 (+), 47
(±)ON:D, 3, 2, 1
OFF:PRNON:8.0 ~ 14.5 V
OFF:0V
41AT POSBONSTOPDCV41 (+), 47
(±)ON:R, N, D, 3
OFF:P, 2, 1ON:8.0 ~ 14.5 V
OFF:0V
28AT POSAONSTOPDCV28 (+), 47
(±)ON:P, R, 3, 2
OFF:N, D, 1ON:8.0 ~ 14.5 V
OFF:0V
2ENG REVONRUNms2, 47Waveform
(PWM)50 ms (1000 rpm)
Page 411 of 2100
DRIVE LINE CONTROL SYSTEM (TOD) 4B2±32
Tech 2 Scan Tool
From 98 MY, Isuzu dealer service departments are
recommended to use Tech 2. Please refer to Tech 2 scan
tool user guide.
901RW257
Legend
(1) PCMCIA Card
(2) SAE 16/19 Adaptor(3) DLC Cable
(4) Tech 2
Page 412 of 2100
4B2±33
DRIVE LINE CONTROL SYSTEM (TOD)
Getting Started
Before operating the Isuzu PCMCIA card with the
Tech 2, the following steps must be performed:
1. The Isuzu 02 System PCMCIA card (1) inserts into
the Tech 2 (4).
2. Connect the SAE 16/19 adapter (2) to the DLC cable
(4).
3. Connect the DLC cable to the Tech 2 (4)
4. Mark sure the vehicle ignition is off.
5. Connect the Tech 2 SAE 16/19 adapter to the vehicle
DLC connector.
826R200011
6. The vehicle ignition turns on.
7. Power up the Tech 2.
8. Verify the Tech 2 power up display.
060RW009
Operating Procedure
The power up screen is displayed when you power up the
tester with the Isuzu systems PCMCIA card. Follow the
operating procedure below.
060R100102
Page 413 of 2100
DRIVE LINE CONTROL SYSTEM (TOD) 4B2±34
060R200079
Page 414 of 2100

4B2±35
DRIVE LINE CONTROL SYSTEM (TOD)
Diagnostic Trouble Codes
CodeTech 2 code
(P code)ItemDiagnosisCheck flow No.
12ÐStart codeNormalÐ
13P1735RefShorted GND6
14P1731Front speed sensorInput abnormality (open, sig or com)2
15P1736RefShorted VB6
16P1737Front speed sensorInput abnormality4
17P1774Inhibitor switchInput abnormality8
21P1716TPSShorted or disconnected wiring,
abnormality in input7
23ÐECUCPU abnormality1
24P1733Rear speed sensorInput abnormality (open, sig or com)3
27P1738Rear speed sensorInput abnormality5
28P1760ADC (+) & AXLE SWOutput abnormality10
31P1721EMC (+)Shorted VB, disconnected coil/wiring or
shorted GND9
32P1761ADC (+)Shorted VB or disconnected wiring11
33P1762ADC (+)Shorted GND12
36ÐECUCPU abnormality1
37P1712ECUCPU abnormality1
38P1714ECUCPU abnormality1
41P1741Hight-Low shift motorShorted GND or disconnected wiring13
42P1773Hight-Low shift motorUser operation error (not failure)14
43P1743Hight-Low shift motorMotor moving more than 5s15
55P1755Hight-Low shift motorInput abnormality of motor position signal16
TPS : Throttle Position Sensor
EMC : Electromagnetic coil
ADC : Shift on the fly (Axle Dis Connect)
Page 415 of 2100
DRIVE LINE CONTROL SYSTEM (TOD) 4B2±36
Diagnosis from Trouble Codes
Diagnose the fault that have been saved to the control
unit according to the system self-diagnostic function.
Check flow
Trouble codePhenomenonStandard
1 23, 36, 37, 38The ECU has failed.Ð
P1712, P1714
StepActionYe sNo
1Turn on the starter switch.
Is the trouble reproduced?Replace the ECU
and conduct the
test run.
Go to
Step 3Go 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
ªTrouble
intermittently
observedº.
Go to Step 3
31. Check that all the parts are mounted.
2. Clear the trouble codes.
Is this step complete?
Verify the repair.Return to Step 3
Page 416 of 2100
4B2±37
DRIVE LINE CONTROL SYSTEM (TOD)
Check flowTrouble codePhenomenonStandard
214Front speed sensor signal open or
GND short speed sensor com
0.2V > sensor voltage
P1731GND short, s eed sensor com
open.
NOTE: The following procedure shows the case that the
front or rear sensor common grounding line is broken.
D04R200005