2004 ISUZU TF SERIES ignition

6E–204 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0251 (Symptom Code A) (Flash Code 53)
Injection Pump 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
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 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 P0251 (Symptom Code A) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
4 Replace the injection pump assembly.
Is the action complete?—Verify repair—

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–205
Diagnostic Trouble Code (DTC) P0251 (Symptom Code B) (Flash Code 53)
Injection Pump 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
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 B) 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 B) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
4 Replace the injection pump assembly.
Is the action complete?—Verify repair—

6E–206 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0251 (Symptom Code D) (Flash Code 53)
Injection Pump 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
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 D) 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 D) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
4 Replace the injection pump assembly.
Is the action complete?—Verify repair—

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–207
Diagnostic Trouble Code (DTC) P0251 (Symptom Code E) (Flash Code 53)
Injection Pump 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
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 E) 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 E) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
4 Was the DTC P1650 (Symptom Code A) or P1651
(Symptom Code B) stored at the same time?
—Go to DTC
Chart P1650
(Symptom
Code A) Go to Step 5
5 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 6
6 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 7Go to Step 8
7 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—
8 Replace the injection pump assembly.
Is the action complete?—Verify repair—

6E –210 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 P0335 (Symptom Code B) or P0335
(Symptom Code D) 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 P0335 (Symptom Code B) or P0335
(Symptom Code D) 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 CKP sensor or ECM connector. If a poor/faulty connection is found,
repair the faulty terminal.
Was the problem found?
— Verify repair Go to Step 5
5 Visually check the CKP sensor. If a faulty installation is found, repair as necessary.
Was the problem found? —Verify repair Go to Step 6
6 Using the DVM and check the CKP sensor 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. Check the resistance of the CKP sensor.
Was the DVM indicated specified value?
Breaker box is not available:
1. Ignition “Off ”, engine “Off ”.
2. Disconnect the ECM connector.
3. Check the resistance of the CKP sensor.
Was the DVM indicated specified value?
Approx imately 0.9k
at 20 °CGo to Step 10 Go to Step 7
Step Action Value(s) Yes No
101
90 9823
1 E-9
C-57(B)
9098


Breaker Box
90
98
C-57(B)

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E –211
7 Using the DVM and check the CKP sensor circuit.
1. Ignition “Off ”, engine “Off ”.
2. Disconnect the CKP sensor connector.
3. Check the resistance of the CKP sensor.
Was the DVM indicated specified value?
Approx imately 0.9k
at 20 °CGo to Step 8Go to Step 14
8 Using the DVM and check the CKP sensor 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. Disconnect the CKP sensor connector.
4. Check the circuit for open, short to sensor wire 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. Disconnect the CKP sensor connector.
4. Check the circuit for open, short to sensor wire 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
1
2
E-9
9098
Breaker Box101




9098
Breake r BoxE-9



6E –212 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
9 Using the DVM and check the CKP sensor circuit.
1. Ignition “On ”, engine “Off ”.
2. Disconnect the CKP sensor connector.
3. Check the circuit for short to power supply circuit.
If the DVM indicated out of specified value, repair
faulty harness and verify repair.
Is the action complete?
Less than 1V Verify repair —
10 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 13 Go to Step 11
11 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 12
12 Check the CKP sensor shield wire for open or short circuit.
Was the problem found? — Repair faulty
harness and verify repair Go to Step 13
Step Action Value(s) Yes No
1
2
VV
E-9
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 –214 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0335 (Symptom Code E) (Flash Code 43)
Engine Speed Input Circuit Range/Performance
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 P0335 (Symptom Code E) 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 P0335 (Symptom Code E) stored in this
ignition cycle? —Go to Step 4 Refer to
Diagnostic Aids and Go to Step
4
4 Ask to the customer whether over-speed condition such as miss-gear shifting etc. has been experienced
or not. — Ex plain the
reason of DTC
to the customer Go to Step 5
5 Check for poor/faulty connection at the CKP sensor or ECM connector. If a poor/faulty connection is found,
repair the faulty terminal.
Was the problem found?
— Verify repair Go to Step 6
101
90 9823
1 E-9
C-57(B)