ISUZU TF SERIES 2004 Workshop Manual

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–189
Step Action Value(s) Yes No
11Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the "SPS (Service Programming System)".
Was the problem solved? - Verify repair Go to Step 12
12R e p l a c e t h e E C M .
I s t h e a c t i o n c o mp l e t e ?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobiliser system
(if equipped) must be linked to the ECM. Refer to
section 11 "Immobilizer System-ECM replacement" for
the ECM/Immobilizer linking procedure. - Verify repair -

6E–190 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0243 (Symptom Code 5) (Flash Code 64)
Turbocharger Wastegate Solenoid "A" Range/Performance
Step Action Value(s) Yes No
1Was the "On-Board Diagnostic (OBD) System Check"
performed?
-Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check
21. Connect the Tech 2.
2. Review and record the failure information.
3. Select "F0: Read DTC Infor As Stored By ECU" in
"F0: Diagnostic Trouble Codes".
Is the DTC P0243 (Symptom Code 5) stored as
"Present Failure"? - Go to Step 3Refer to
Diagnostic Aids
and Go to Step
3
31. Using the Tech 2, ignition "On" and engine "Off".
2. Select "F1: Clear DTC Information" in "F0:
Diagnostic Trouble Codes" with the Tech 2 and
c l e a r t h e D T C i n f o r m a t i o n .
3. Operate the vehicle and monitor the "F0: Read
DTC Infor As Stored By ECU" in the "F0:
Diagnostic Trouble Codes".
Was the DTC P0243 (Symptom Code 5) stored in this
ignition cycle? - Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4
4Visually check the vacuum regulating valve.
If a problem is found, repair as necessary.
Was the problem found? - Verify repair Go to Step 5
5Using the DVM and check the wastegate control
solenoid.
1 . I g n i t i o n " O f f " , e n g i n e " O f f " .
2. Disconnect the wastegate solenoid connector.
3. Measure the resistance of wastegate solenoid
coil.
Does the tester indicate standard resistance?
Approx imately
14.7 - 16.1

at 20C
Go to Step 8Go to Step 6
6Substitute a known good wastegate control solenoid
a n d re ch e c k.
Was the problem solved? - Go to Step 7Go to Step 8
7Replace the wastegate control solenoid.
Is the action complete? - Verify repair -
8Using the pressure gauge and check the turbocharger
wastegate valve operation for broken diaphragm.
If a problem is found, repair as necessary.
Was a problem found? - Go to Step 9Go to Step 10
9Replace the turbocharger wastegate valve .
Is the action complete? - Verify repair -
Wastegate Solenoid





4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–191
Step Action Value(s) Yes No
10Check for poor/faulty connection at the vacuum
pressure sensor or ECM connector. If a poor/faulty
connection is found, repair as necessary.
Was the problem found?
- Verify repair Go to Step 11
11V i s u a l l y c h e c k t h e v a c u u m p r e s s u r e s e n s o r .
Was the problem found? - Go to Step 13Go to Step 12
12Using the DVM and check the vacuum pressure
sensor signal circuit.
1. Ignition "On", engine "Off".
2. Disconnect the vacuum pressure sensor
connector.
3. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
Less than 1V Go to Step 15Repair faulty
harness and
verify repair
13Substitute a known good vacuum pressure sensor
a s s e m b l y a n d r e c h e c k .
Was the problem solved? - Go to Step 14Go to Step 15
14Replace the vacuum pressure sensor assembly.
Is the action complete? - Verify repair -
15Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the "SPS (Service Programming System)".
Was the problem solved? - Verify repair Go to Step 16
16R e p l a c e t h e E C M .
I s t h e a c t i o n c o mp l e t e ?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobiliser system
(if equipped) must be linked to the ECM. Refer to
section 11 "Immobilizer System-ECM replacement" for
the ECM/Immobilizer linking procedure. - Verify repair -
C-57C-123

C-124
V

6E–192 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0243 (Symptom Code 6) (Flash Code 64)
Turbocharger Wastegate Solenoid "A" Malfunction
Step Action Value(s) Yes No
1Was the "On-Board Diagnostic (OBD) System Check"
performed?
-Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check
21. Connect the Tech 2.
2. Review and record the failure information.
3. Select "F0: Read DTC Infor As Stored By ECU" in
"F0: Diagnostic Trouble Codes".
Is the DTC P0243 (Symptom Code 6) stored as
"Present Failure"? - Go to Step 3Refer to
Diagnostic Aids
and Go to Step
3
31. 1Using the Tech 2, ignition "On" and engine "Off".
2. Select "F1: Clear DTC Information" in "F0:
Diagnostic Trouble Codes" with the Tech 2 and
c l e a r t h e D T C i n f o r m a t i o n .
3. Operate the vehicle and monitor the "F0: Read
DTC Infor As Stored By ECU" in the "F0:
Diagnostic Trouble Codes".
Was the DTC P0243 (Symptom Code 6) stored in this
ignition cycle? - Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4
4Visually check the turbocharger wastegate valve and
hose.
If the hose is clogged or disconnected, repair as
n e c e s s a r y .
Was the problem found? - Verify repair Go to Step 5
5Using the pressure gauge and check the turbocharger
wastegate valve operation for broken diaphragm or
restrict shaft operation.
If a problem is found, repair as necessary.
Was a problem found? - Go to Step 6Go to Step 7
6R e p l a c e t h e t u r b o c h a r g e r w a s t e g a t e v a l v e .
Is the action complete? - Verify repair -
7Check for poor/faulty connection at the MAF sensor or
ECM connector. If a poor/faulty connection is found,
repair as necessary.
Was the problem found?
- Verify repair Go to Step 8
8V i s u a l l y c h e c k t h e M A F s e n s o r .
Was the problem found? - Go to Step 10Go to Step 9
C-57
C-116





4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–193
Step Action Value(s) Yes No
9Using the DVM and check the MAF sensor signal
circuit.
1. Ignition "On", engine "Off".
2. Disconnect the MAF sensor connector.
3. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
Less than 1V Go to Step 12Repair faulty
harness and
verify repair
10Substitute a known good MAF & IAT sensor assembly
a n d re ch e c k.
Was the problem solved? - Go to Step 11Go to Step 12
11Replace the MAF & IAT sensor assembly.
Is the action complete? - Verify repair -
12Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the "SPS (Service Programming System)".
Was the problem solved? - Verify repair Go to Step 13
13R e p l a c e t h e E C M .
I s t h e a c t i o n c o mp l e t e ?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobiliser system
(if equipped) must be linked to the ECM. Refer to
section 11 "Immobilizer System-ECM replacement" for
the ECM/Immobilizer linking procedure. - Verify repair -
C-116
V

6E–194 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0243 (Symptom Code 8) (Flash Code 64)
Turbocharger Wastegate Solenoid "A" High
Step Action Value(s) Yes No
1Was the "On-Board Diagnostic (OBD) System Check"
performed?
-Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check
21. Connect the Tech 2.
2. Review and record the failure information.
3. Select "F0: Read DTC Infor As Stored By ECU" in
"F0: Diagnostic Trouble Codes".
Is the DTC P0243 (Symptom Code 8) stored as
"Present Failure"? - Go to Step 3Refer to
Diagnostic Aids
and Go to Step
3
31. Using the Tech 2, ignition "On" and engine "Off".
2. Select "F1: Clear DTC Information" in "F0:
Diagnostic Trouble Codes" with the Tech 2 and
c l e a r t h e D T C i n f o r m a t i o n .
3. Operate the vehicle and monitor the "F0: Read
DTC Infor As Stored By ECU" in the "F0:
Diagnostic Trouble Codes".
Was the DTC P0243 (Symptom Code 8) stored in this
ignition cycle? - Go to Step 4Refer to
Diagnostic Aids
4Check for poor/faulty connection at the wastegate
control solenoid or ECM connector. If a poor/faulty
connection is found, repair as necessary.
Was the problem found? - Verify repair Go to Step 5
5Using the DVM and check the wastegate control
solenoid.
1 . I g n i t i o n " O f f " , e n g i n e " O f f " .
2. Disconnect the wastegate solenoid connector.
3. Measure the resistance of wastegate solenoid
coil.
Does the tester indicate standard resistance?
Approx imately
14.7- 16.1
at
20C
Go to Step 6Go to Step 8
Wastegate Solenoid





4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–195
Step Action Value(s) Yes No
6Using the DVM and check the wastegate control
solenoid circuit.
1. Ignition "Off", engine "Off".
2. Remove the wastegate control solenoid connector
and ECM connector.
3. Check the circuit for short to voltage circuit.
Was the DVM indicated specified value?
No continuity Go to Step 10Go to Step 7
7Repair the short to voltage circuit.
Is the action complete? - Verify repair -
8Substitute a known good wastegate control solenoid
a n d re ch e c k.
Was the problem solved? - Go to Step 9Go to Step 10
9Replace the wastegate control solenoid.
Is the action complete? - Verify repair -
10Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the "SPS (Service Programming System)".
Was the problem solved? - Verify repair Go to Step 11
11R e p l a c e t h e E C M .
I s t h e a c t i o n c o mp l e t e ?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobiliser system
(if equipped) must be linked to the ECM. Refer to
section 11 "Immobilizer System-ECM replacement" for
the ECM/Immobilizer linking procedure. - Verify repair -
C-123

6E–196 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0251 (SYMPTOM CODE 6)
(FLASH CODE 53) INJECTION PUMP MALFUNCTION
DIAGNOSTIC TROUBLE CODE (DTC) P0251 (SYMPTOM CODE 7)
(FLASH CODE 53) INJECTION PUMP MALFUNCTION
DIAGNOSTIC TROUBLE CODE (DTC) P0251 (SYMPTOM CODE 9)
(FLASH CODE 53) INJECTION PUMP MALFUNCTION
DIAGNOSTIC TROUBLE CODE (DTC) P0251 (SYMPTOM CODE A)
(FLASH CODE 53) INJECTION PUMP MALFUNCTION
DIAGNOSTIC TROUBLE CODE (DTC) P0251 (SYMPTOM CODE B)
(FLASH CODE 53) INJECTION PUMP MALFUNCTION
DIAGNOSTIC TROUBLE CODE (DTC) P0251 (SYMPTOM CODE D)
(FLASH CODE 53) INJECTION PUMP MALFUNCTION
DIAGNOSTIC TROUBLE CODE (DTC) P0251 (SYMPTOM CODE E)
(FLASH CODE 53) INJECTION PUMP MALFUNCTION

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–197
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The ECM is calculates an injection quantity and an
injection timing using the various sensors. And the PSG
controls the high pressure solenoid valve depending on
programmed pump map data.
The signal of desired injection quantity and actual injec-
tion quantify are ex changed via the CAN-bus between
the PSG and ECM.
If the relation of engine speed signal and doubled pump
camshaft speed signal ex cessively large, DTC P0251
(Symptom Code 7) will be stored.
If the CAN high or low circuit is defected, DTC P0251
(Symptom Code E) will be stored.
Diagnostic Aids
An intermittent may be caused by the following:
Poor connections.
Misrouted harness.
Rubbed through wire insulation.
Broken wire inside the insulation.
Check for the following conditions:
Poor connection at ECM and PSG-Inspect harness
connectors for backed out terminals, improper
mating, broken locks, improperly formed or damaged
terminals, and poor terminal to wire connection.
Damaged harness-Inspect the wiring harness for
damage. If the harness appears to be OK, observe
the “Injection Quantity” display on the Tech2 while
moving connectors and wiring harness related to the
sensor.
Diagnostic Trouble Code (DTC) P0251 (Symptom Code 6) (Flash Code 53)
Injection Pump Malfunction
Flash
CodeCode Symptom
CodeMIL DTC Name DTC Setting Condition Fail-Safe (Back Up)
53 P0251 6 ON Injection Pump Malfunction 1. No pump camshaft speed
se nsor erro r.
2. High pressure solenoid
v a lv e co ntro l pulse w idth
doe s no t ma tch with
desired fuel injection quan-
tity. 1. MAB (fuel cutoff solenoid
valve) is operated.
2. Desired injection quantity
becomes 0mg/strk.
7 ON Injection Pump Malfunction 1. No pump camshaft speed
se nsor erro r.
2. No CKP senso r e rror.
3. Difference of engine speed
and doubled pump cam-
shaft speed is more than
720rpm (4JA1-TC) or 690
rpm (4JH1-TC).
9 ON Injection Pump Malfunction No pump map programmed in
the PSG (pump co ntrol unit)
or PSG malfunction.
A ON Injection Pump Malfunction EEPROM or A/D converter
malfunctio n in the PSG (pump
control unit).Fuel inje ctio n qua ntity is
reduced.
B ON Injection Pump Malfunction PSG (pump control unit) rec-
ognized high pressure sole -
noid valve drive circuit error.No fa il-sa fe fun ctio n.
D ON Injection Pump Malfunction PSG (pump control unit) could
no t me asure the high pres-
sure solenoid valve drive volt-
age.
E ON Injection Pump Malfunction ECM could not accept PSG
(pump co ntrol unit) messa ge.1. MAB (fuel cutoff solenoid
valve) is operated.
2. Desired injection quantity
becomes 0mg/strk.
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check

6E–198 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
2 1. Connect the Tech 2.
2. Review and record the failure information.
3. Select “F0: Read DTC Infor As Stored By ECU” in
“F0: Diagnostic Trouble Codes”.
Is the DTC P0251 (Symptom Code 6) stored as
“Present Failure”?—Go to Step 3Refer to
Diagnostic Aids
and Go to Step
3
3 1. Using the Tech 2, ignition “On” and engine “Off”.
2. Select “F1: Clear DTC Information” in “F0:
Diagnostic Trouble Codes” with the Tech 2 and
clear the DTC information.
3. Operate the vehicle and monitor the “F0: Read
DTC Infor As Stored By ECU” in the “F0:
Diagnostic Trouble Codes”.
Was the DTC P0251 (Symptom Code 6) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
4 Replace the injection pump assembly.
Is the action complete?—Verify repair— Step Action Value(s) Yes No