2004 ISUZU TF SERIES ECU

6E–126 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
55 P1605 E ON EEPROM Defect EEPROM checksum does
not match with the read
check sum during
initialization of the ECM.EEPROM checksum match
with the read check sum
during initialization of the
ECM.ECM malfunction.
——
56 P1610 A - Security Key and Security
Code not ProgrammedImmobilizer functions are not
programmed in the ECM.1 . E n g i n e d o e s n o t s t a r t .
2. Check engine lamp flash. No recovery. ECM malfunction.
— B****
56 P1611 A - Wrong Security Code
EnteredReceived security code is not
correct.1 . E n g i n e d o e s n o t s t a r t .
2. Check engine lamp flash. N o r e c o v e r y . 1 . E C M m a l f u n c t i o n .
2. Immobilizer control unit
m a l f u n c t i o n .
3. Transponder key
malfunction.— B****
56 P1612 A - Immobilizer No or Wrong
SignalReceived challenge signal is
not correct or not received.1 . E n g i n e d o e s n o t s t a r t .
2. Check engine lamp flash. No recovery. 1. ECM and immobilizer
control unit
communication circuit
open circuit, short to
ground circuit or short to
voltage circuit.
2 . E C M m a l f u n c t i o n .
3. Immobilizer control unit
m a l f u n c t i o n .
4. Transponder key
malfunction.2 7 /
35B****
56 P1613 A - Immobilizer No or Wrong
SignalReceived response signal is
not correct or not received.1 . E n g i n e d o e s n o t s t a r t .
2. Check engine lamp flash. No recovery. 1. ECM and immobilizer
control unit
communication circuit
open circuit, short to
ground circuit or short to
voltage circuit.
2 . E C M m a l f u n c t i o n .
3. Immobilizer control unit
m a l f u n c t i o n .
4. Transponder key
malfunction.2 7 /
35B****
56 P1614 A - Wrong Transponder Key Received response signal is
not correct from the
transponder key.1 . E n g i n e d o e s n o t s t a r t .
2. Check engine lamp flash. N o r e c o v e r y . 1 . E C M m a l f u n c t i o n .
2. Immobilizer control unit
m a l f u n c t i o n .
3. Transponder key
malfunction.— B****
76 P1625 A OFF ECM Main Relay Switched
Off Too EarlyWhen ignition switch was
turned off, timing of the ECM
main relay turning off is too
early.No fail-safe function. No recovery. ECM malfunction.
3 /
58—
B OFF ECM Main Relay Switched
Off Too LateWhen ignition switch was
turned off, timing of the ECM
main relay turning off is too
late or does not off.No recovery. 1. ECM main relay
m a l f u n c t i o n .
2. ECM malfunction.3 /
58— Flash
CodeCodeSymptom
CodeMILDTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Related Failure PartsRelated
ECM Pin
No.Related
Multiple
DTC4JA1-TC
(MT)4JH1-TC
(MT)4JH1-TC
(AT)

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–129
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The mass air flow (MAF) sensor is part of the intake air
system. It is fitted between the air cleaner and
turbocharger and measure the mass air flowing into the
engine.
The mass air flow (MAF) sensor element measures the
partial air mass through a measurement duct on the
sensor housing.
The ECM monitors the MAF sensor supply voltage and
MAF sensor output voltage. The supply voltage is out of
range, DTC P0100 (Symptom Code 7) or P0100
(Symptom Code 9) will be stored. The output voltage
ex cessively high or low, DTC P0100 (Symptom Code B)
or P0100 (Symptom Code C) 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-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 “Mass Air Flow” display on the Tech2 while
moving connectors and wiring harness related to the
sensor.
Diagnostic Trouble Code (DTC) P0100 (Symptom Code 7) (Flash Code 65)
Mass Air Flow (MAF) Sensor Voltage Supply Circuit High Input
Flash
CodeCodeSymptom
CodeMIL DTC Name DTC Setting Condition Fail-Safe (Back Up)
65 P0100 7 ON Ma ss Air Flo w (MAF) Senso r
Voltage Supply Circuit High
InputMAF sensor power supply
voltage is more than 5.2V.ECM uses ma ss a ir flo w
1600mg/strk & EGR 10% co n-
ditions as substitute.
9 ON Mass Air Flow (MAF) Sensor
Voltage Supply Circuit Low
InputMAF sensor power supply
voltage is below 4.6V.
B ON Mass Air Flow (MAF) Sensor
Output Circuit Low Input1. Engine speed is between
600rpm and 5000rpm.
2. MAF se nsor o utput is
below -33.7mg/strk.
C ON Mass Air Flow (MAF) Sensor
Output Circuit High Input1. Engine speed is between
600rpm and 5000rpm.
2. MAF sensor output is more
tha n 1378mg/strk (4JA1-TC)
o r 1784mg/strk (4JH1-TC).
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
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 P0100 (Symptom Code 7) stored as
“Present Failure”?—Go to Step 3Refer to
Diagnostic Aids
and Go to Step
3

6E –130 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
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 P0100 (Symptom Code 7) stored in this
ignition cycle? —Go to Step 4 Refer to
Diagnostic Aids and Go to Step
4
4 Check 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 5
5 Visually check the MAF sensor. Was the problem found? —Go to Step 11 Go to Step 6
6 Using the DVM and check the MAF sensor power supply circuit.
1. Ignition “On ”, engine “Off ”.
2. Disconnect the MAF & IAT sensor connector.
3. Check the circuit for short to battery voltage circuit.
Was the DVM indicated specified value?
Approx imately 5.0V Go to Step 11 Less than 1V:
Go to Step 7
More than
specified value: Go to Step 8
7 Repair the open circuit between the ECM and MAF sensor.
Was the problem solved?
— Verify repair Go to Step 8
Step Action Value(s) Yes No
92
88 83
2 3
4
5
C-116
C-57(B)
V
4
C-116
83
4
C-116
C-57(B)

6E –132 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0100 (Symptom Code 9) (Flash Code 65)
Mass Air Flow (MAF) Sensor Voltage Supply Circuit Low Input
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check ”
performed?
— Go to Step 2 Go to
On Board
Diagnostic
(OBD) System Check
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 P0100 (Symptom Code 9) stored as
“ Present Failure ”? —Go to Step 3 Refer 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 P0100 (Symptom Code 9) stored in this
ignition cycle? —Go to Step 4 Refer to
Diagnostic Aids and Go to Step
4
4 Check 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 5
5 Visually check the MAF sensor. Was the problem found? —Go to Step 10 Go to Step 6
6 Using the DVM and check the MAF sensor power supply circuit.
1. Ignition “On ”, engine “Off ”.
2. Disconnect the MAF & IAT sensor connector.
3. Check the circuit for short to ground circuit.
Was the DVM indicated specified value?
Approx imately 5.0V Go to Step 10Go to Step 7
92
88 83
2 3
4
5
C-116
C-57(B)
V
4
C-116

6E –134 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0100 (Symptom Code B) (Flash Code 65)
Mass Air Flow (MAF) Sensor Output Circuit Low Input
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check ”
performed?
— Go to Step 2 Go to
On Board
Diagnostic
(OBD) System Check
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 P0100 (Symptom Code B) stored as
“ Present Failure ”? —Go to Step 3 Refer 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 P0100 (Symptom Code B) stored in this
ignition cycle? —Go to Step 4 Refer to
Diagnostic Aids and Go to Step
4
4 Check 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 5
5 Visually check the MAF sensor. Was the problem found? —Go to Step 11 Go to Step 6
92
88 83
2 3
4
5
C-116
C-57(B)

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E –137
Diagnostic Trouble Code (DTC) P0100 (Symptom Code C) (Flash Code 65)
Mass Air Flow (MAF) Sensor Output Circuit High Input
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check ”
performed?
— Go to Step 2 Go to
On Board
Diagnostic
(OBD) System Check
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 P0100 (Symptom Code C) stored as
“ Present Failure ”? —Go to Step 3 Refer 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 P0100 (Symptom Code C) stored in this
ignition cycle? —Go to Step 4 Refer to
Diagnostic Aids and Go to Step
4
4 Check 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 5
5 Visually check the MAF sensor. Was the problem found? —Go to Step 11 Go to Step 6
92
88 83
2 3
4
5
C-116
C-57(B)

6E–142 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0105 (Symptom Code 1) (Flash Code 34)
Vacuum Pressure Sensor Circuit High Input
Step Action Value(s) Yes No
1 Was the "On-Board Diagnostic (OBD) System Check"
performed?
-Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check
2 1 . 1 C o n n e c t t h e Te c h 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 P0105 (Symptom Code 1) 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
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 P0105 (Symptom Code 1) stored in this
ignition cycle? - Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4
4 Check 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 5
5 V i s u a l l y c h e c k t h e v a c u u m s e n s o r.
Was the problem found? - Go to Step 9Go to Step 6
C-124C-57





4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–145
Diagnostic Trouble Code (DTC) P0105 (Symptom Code 2) (Flash Code 34)
Vacuum Pressure Sensor Circuit Low Input
Step Action Value(s) Yes No
1 Was the "On-Board Diagnostic (OBD) System Check"
performed?
-Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check
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 P0105 (Symptom Code 2) 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
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 P0105 (Symptom Code 2) stored in this
ignition cycle? - Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4
4 Check 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 5
5 V 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 9Go to Step 6
C-124C-57