2004 ISUZU TF SERIES ignition

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–215
6 Using the DVM and check the CKP sensor signal.
1. Ignition “On”, engine “On”.
2. Measure the CKP output voltage at the sensor
and ECM.
Does the tester indicate standard voltage?
If a oscilloscope is available, monitor the CKP sensor
signal. Does the oscilloscope indicate correct wave
form?
Go to Step 9Go to Step 7
7 Remove the CKP sensor from the flywheel housing
and visually check.
Check for the following conditions.
Objects sticking the CKP sensor.
Objects sticking the CKP sensor pulser.
If a problem is found, repair as necessary.
Was the problem found? —Verify repair Go to Step 8
8 Check the CKP sensor shield wire for open or short
circuit.
Was the problem found?—Repair faulty
harness and
verify repair Go to Step 9
9 Check any accessory parts which may cause electric
interference or magnetic interference.
Was the problem found?—Remove the
accessory parts
and verify repair Go to Step 10
10 Substitute a known good CKP sensor and recheck.
Was the problem solved?—Go to Step 11Go to Step 12
11 Replace the CKP sensor.
Was the problem solved?—Verify repair Go to Step 12
12 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 13 Step Action Value(s) Yes No
Measurement Point Voltage (V) (AC Range)
At CKP se nso r te rminal 2 & 1 Appro ximate ly 1.1 V a t
2000rpm
At ECM C57 co nnecto r 90 & 98
Cra nksha ft Po sitio n (CKP) Sensor Refe rence Wav e Form
0V
Mea sure me nt Terminal: 90(+) 98(-)
Measurement Scale: 20V/div 2ms/div
Mea sure me nt Co ndition: Approx imately 2000rpm

6E –218 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
 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 P0380 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) P0380 (Symptom Code 4) (Flash Code 66) Glow Relay Circuit Voltage Low
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 P0380 (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 P0380 (Symptom Code 4) 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 glow relay 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 glow relay. 1. Ignition “Off ”, engine “Off ”.
2. Remove the glow relay from the relay box .
3. Check the relay coil.
Was the DVM indicated specified value?
Approx imately 105
Go to Step 6 Replace glow
relay and verify repair
94
3
4
2
1
X-5
C-57
Grow Relay




4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E –219
6 Using the DVM and check the glow relay power
supply circuit.
1. Ignition “On ”, engine “Off ”.
2. Remove the glow relay from the relay box .
3. Check the circuit for open or short to ground circuit.
Was the DVM indicated specified value?
10-14.5V Go to Step 8Go to Step 7
7 Repair the open or short to ground circuit between the ECM main relay and glow relay.
Is the action complete? —Verify repair —
8 Using the DVM and check the glow relay ground circuit.
Breaker box is available:
1. Ignition “Off ”, engine “Off ”.
2. Install the breaker box as type A. (ECM disconnected) Ref. Page 6E-103
3. Remove the glow relay from the relay box .
4. Check the circuit for open or short to ground circuit.
Was the problem found?
Breaker box is not available: 1. Ignition “Off ”, engine “Off ”.
2. Disconnect the ECM connector.
3. Remove the glow relay from the relay box .
4. Check the circuit for open or short to ground circuit.
Was the problem found?
— Repair faulty
harness and verify repair Go to Step 9
Step Action Value(s) Yes No
2
V
X-5
X- 594Breaker Box




3
94
X-5
C-57

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 –224 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
7 Check for poor/faulty connection at the meter
connector and ECM connector. If a poor/faulty
connection is found, repair as necessary.
Was the problem found?
— Verify repair Go to Step 8
8 Using the DVM and check the glow time telltale circuit. Breaker box is available:
1. Ignition “Off ”, engine “Off ”.
2. Install the breaker box as type A. (ECM disconnected) Ref. Page 6E-103
3. Remove the meter connector.
4. Check the circuit for open or short to ground circuit.
Was the problem found?
Breaker box is not available:
1. Ignition “Off ”, engine “Off ”.
2. Disconnect the ECM connector.
3. Remove the meter connector.
4. Check the circuit for open or short to ground circuit.
Was the problem found?
— Repair faulty
harness and verify repair Go to Step 9
Step Action Value(s) Yes No
43
6
30
B-24
C-56
43Breaker BoxB-24




43
6
B-24
C-56

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