ECU ISUZU TF SERIES 2004 Workshop Manual

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–221
Diagnostic Trouble Code (DTC) P0380 (Symptom Code 8) (Flash Code 66)
Glow Relay Circuit Voltage 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
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 P0380 (Symptom Code 8) 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 P0380 (Symptom Code 8) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
4 Is 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 5
5 Substitute a known good ECM and recheck.
Was the problem solved?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure. —Go to Step 6—
6 Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer 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—

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–223
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, andpoor terminal to wire connection.
Damaged harness-Inspect the wiring harness for
damage. If the harness appears to be OK, observe
the DTC P0381 display on the Tech2 while moving
connectors and wiring harnesses. A change in the
display will indicate the location of the fault.
Diagnostic Trouble Code (DTC) P0381 (Symptom Code 4) (Flash Code 67)
Glow Plug Indicator Circuit Voltage Low
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 P0381 (Symptom Code 4) 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 P0381 (Symptom Code 4) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4
4 1. Ignition “On”, engine “Off”.
2. Check the glow plug indicator lamp.
Does the lamp turn “On”?—Go to Step 5Go to Step 6
5 1. Ignition “On”, engine “Off”.
2. Check the glow plug indicator lamp.
Does the lamp turn “Off”?—Go to Step 9Go to Step 7
6 Check the glow plug indicator lamp bulb.
If the bulb is burnt out, repair as necessary.
Was the problem found?—Verify repair Go to Step 7

6E–226 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0381 (Symptom Code 8) (Flash Code 67)
Glow Plug Indicator Circuit Voltage 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
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 P0381 (Symptom Code 8) 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 P0381 (Symptom Code 8) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
4 Is 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 5
5 Substitute a known good ECM and recheck.
Was the problem solved?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure. —Go to Step 6—
6 Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer 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—

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E –229
Diagnostic Trouble Code (DTC) P0400 (Symptom Code 3) (Flash Code 32)
Exhaust Gas Recirculation Flow Excessive Detected
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 P0400 (Symptom Code 3) 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 P0400 (Symptom Code 3) stored in this
ignition cycle? —Go to Step 4 Refer to
Diagnostic Aids and Go to Step
4
4 Remove the MAF & IAT sensor assembly and check for the following conditions.
 Objects blocking the air cleaner.
 Objects blocking the MAF sensor.
 Vacuum leaking at intake duct.
 Objects blocking the turbocharger.
If a problem is found, repair as necessary.
Was the problem found? —Verify repair Go to Step 5
5 Remove the MAF & IAT sensor assembly and visually check.
Was the problem found? —Go to Step 6 Go to Step 8
6 Substitute a known good MAF & IAT sensor assembly and recheck.
Was the problem solved? —Go to Step 7 Go to Step 8
7 Replace the MAF & IAT sensor assembly. Is the action complete? —Verify repair —
8 Using the DVM and check the EGR EVRV. 1. Ignition “Off ”, engine “Off ”.
2. Disconnect the EGR EVRV connector.
3. Measure the resistance of EGR EVRV solenoid coil.
Does the tester indicate standard resistance?
Approx imately 14
at 20 °CGo to Step 11 Go to Step 9
1
2
EGR EVRV
1
2

6E –232 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0400 (Symptom Code 4) (Flash Code 32)
Exhaust Gas Recirculation Circuit Short to Ground or Open Circuit
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 P0400 (Symptom Code 4) 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 P0400 (Symptom Code 4) stored in this
ignition cycle? —Go to Step 4 Refer to
Diagnostic Aids and Go to S tep
4
4 Check for poor/faulty connection at the EGR EVRV or ECM connector. If a poor/faulty connection is found,
repair as necessary.
Was the problem found?
— Verify repair Go to Step 5
5 Using the DVM and check the EGR EVRV. 1. Ignition “Off ”, engine “Off ”.
2. Disconnect the EGR EVRV connector.
3. Measure the resistance of EGR EVRV solenoid coil.
Does the tester indicate standard resistance?
Approx imately 14
at 20 °CGo to Step 6Go to Step 9
9712
C-115
C-57
1
2
EGR EVRV
1
2

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E –235
Diagnostic Trouble Code (DTC) P0400 (Symptom Code 5) (Flash Code 32)
Exhaust Gas Recirculation Flow Insufficient Detected
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 P0400 (Symptom Code 5) 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 P0400 (Symptom Code 5) stored in this
ignition cycle? —Go to Step 4 Refer to
Diagnostic Aids and Go to Step 4
4 Visually check the EGR control vacuum hose. If the hose is clogged or disconnected, repair as
necessary.
Was the problem found? —Verify repair Go to Step 5
5 Using the DVM and check the EGR EVRV. 1. Ignition “Off ”, engine “Off ”.
2. Disconnect the EGR EVRV connector.
3. Measure the resistance of EGR EVRV solenoid coil.
Does the tester indicate standard resistance?
Approx imately 14
at 20 °C Go to Step 8 Go to Step 6
6 Substitute a known good EGR EVRV and recheck. Was the problem solved? —Go to Step 7 Go to Step 8
7 Replace the EGR EVRV. Is the action complete? —Verify repair —
1
2
EGR EVRV
1
2

6E –238 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0400 (Symptom Code 8) (Flash Code 32)
Exhaust Gas Recirculation Circuit Short to Battery
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 P0400 (Symptom Code 8) 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 P0400 (Symptom Code 8) stored in this
ignition cycle? —Go to Step 4 Refer to
Diagnostic Aids
4 Check for poor/faulty connection at the EGR EVRV or ECM connector. If a poor/faulty connection is found,
repair as necessary.
Was the problem found?
— Verify repair Go to Step 5
5 Using the DVM and check the EGR EVRV. 1. Ignition “Off ”, engine “Off ”.
2. Disconnect the EGR EVRV connector.
3. Measure the resistance of EGR EVRV solenoid coil.
Does the tester indicate standard resistance?
Approx imately 14
at 20 °CGo to Step 6Go to Step 8
9712
C-115
C-57
1
2
EGR EVRV
1
2

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–241
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The VSS is a magnet rotated by the transmission output
shaft. The VSS uses a hall element. It interacts with the
magnetic field treated by the rotating magnet. It outputs
pulse signal. The 12 volts operating supply from the
meter fuse.
The engine control module (ECM) calculates the vehicle
speed by VSS.
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 DTC P0500 display on the Tech2 while moving
connectors and wiring harnesses. A change in the
display will indicate the location of the fault.
Diagnostic Trouble Code (DTC) P0500 (Symptom Code 1) (Flash Code 24)
Vehicle Speed Sensor Circuit High Input
Flash
CodeCode Symptom
CodeMIL DTC Name DTC Setting Condition Fail-Safe (Back Up)
24 P0500 1 ON
at next
ignitio n
cy cleVehicle Spe ed Se nsor Circuit
High InputVehicle speed is more than
200km/h.ECM uses v ehicle spe ed 5km/
h condition as substitute.
AON
at next
ignitio n
cy cleVehicle Speed Sensor Input
Signal Frequency Too HighInput signal frequency is too
high.ECM uses v ehicle spe ed 5km/
h condition as substitute.
BON
at next
ignitio n
cy cleVehicle Spe ed Se nsor Inco r-
re ct Signal1. Engine speed is more than
3200rpm (4JA1-TC) o r
3600rpm (4JH1-TC).
2. Fuel injection quantity is
more than 30mg/strk
(4JA1-TC) or 41mg/strk
(4JH1-TC).
3. Vehicle speed is below
1.5km/h.Fuel injection quantity is
re duced.
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 P0500 (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
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 P0500 (Symptom Code 1) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–245
Diagnostic Trouble Code (DTC) P0500 (Symptom Code A) (Flash Code 24)
Vehicle Speed Sensor Input Signal Frequency Too 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
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 P0500 (Symptom Code A) 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 P0500 (Symptom Code A) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4
4 Perform test drive and check the speed meter.
Does the speed meter indicate correct vehicle speed.—Go to Step 5Go to Step 6
5 Perform test drive and use the Tech 2.
Monitor the “Vehicle Speed” in the data display.
Does the Tech 2 indicate correct vehicle speed as
same as the speed meter indication in the instrument
panel?—Go to Step 10Go to Step 7
6 Remove the VSS from the housing case and visually
check.
Was the problem found? —Go to Step 8Go to Step 7

6E –248 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0500 (Symptom Code B) (Flash Code 24)
Vehicle Speed Sensor Incorrect Signal
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 P0500 (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 P0500 (Symptom Code B) stored in this
ignition cycle? —Go to Step 4 Refer to
Diagnostic Aids and Go to Step
4
4 Perform test drive and check the speed meter. Does the speed meter indicate correct vehicle speed. —Go to Step 5 Go to Step 6
5 Perform test drive and use the Tech 2. Monitor the “Vehicle Speed ” in the data display.
Does the Tech 2 indicate correct vehicle speed as
same as the speed meter indication in the instrument
panel? —Go to Step 17 Go to Step 7
6 Check for poor/faulty connection at the VSS, TCM (A/ T 2WD) and meter connectors. If a poor/faulty
connection is found, repair the faulty terminal.
Was the problem found?
— Verify repair Go to Step 8
13
2
9 10
10 B-24
C-94(10) E-44