4jh1 ISUZU TF SERIES 2004 Workshop Manual

6E–306 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P1335 (SYMPTOM CODE A)
(FLASH CODE 43) ENGINE SPEED OUTPUT CIRCUIT MALFUNCTION
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The CKP sensor is located on top of the flywheel
housing of the flywheel and fix ed with a bolt. The CKP
sensor is of the magnet coil type. The inductive pickup
sensors four gaps in the flywheel ex citer ring and is
used to determine the engine speed and engine
cylinder top dead center.
The ECM converts sine wave signal to square wave
signal. And this signal is provided from the ECM to
pump control unit (PSG).
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.
Flash
CodeCode Symptom
CodeMIL DTC Name DTC Setting Condition Fail-Safe (Back Up)
43 P1335 A ON Engine Speed Output Circuit
Malfunctio nThe PSG (pump control unit)
is recognized defective
engine speed signal form the
ECM.Fuel inje ctio n qua ntity is
reduced.

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–307
Damaged harness-Inspect the wiring harness for
damage. If the harness appears to be OK, observe
the “Engine Speed” display on the Tech2 whilemoving connectors and wiring harness related to the
sensor.
Diagnostic Trouble Code (DTC) P1335 (Symptom Code A) (Flash Code 43)
Engine Speed Output Circuit 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 P1335 (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 P1335 (Symptom Code A) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4
4 Was the DTC P0335 (Symptom Code B) or P0335
(Symptom Code D) stored at the same time?
—Go to DTC
Chart P0335
(Symptom
Code B)
(Symptom
Code C)Go to Step 5
5 Check for poor/faulty connection at the ECM or PSG
(pump control unit) connector. If a poor/faulty
connection is found, repair the faulty terminal.
Was the problem found?
—Verify repair Go to Step 6
91
8C-57(B) E-6

6E–308 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
6 If a oscilloscope is available, monitor the CKP sensor
output signal. Does the oscilloscope indicate correct
wav e form?
—Go to Step 13Not available:
Go to Step 7
Fix ed at low:
Go to Step 7
Fix ed at High:
Go to Step 8 Step Action Value(s) Yes No
Crankshaft Position (CKP) Sensor & TDC Output Signal
Re fe re nce Wa v e Fo rm
CH1
0V

CH2
0V

Measurement Terminal: CH1: 90(+) / CH2: 91(+) GND(-)
Measurement Scale: CH1: 50V/div / CH2: 10V/div 1ms/div
Measurement Condition: Approximately 2000rpm

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–309
7 Using the DVM and check the CKP sensor output
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 PSG (pump control unit)
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. Disconnect the PSG (pump control unit)
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 8
8 Using the DVM and check the CKP sensor output
circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the PSG (pump control unit)
connector.
3. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
Less than 1V Go to Step 9Repair faulty
harness and
verify repair Step Action Value(s) Yes No
E-691Breaker Box




918 C-57(B) E-6
8
V
E-6

6E–310 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
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 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 11
11 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 12Go to Step 13
12 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—
13 Replace the injection pump assembly.
Is the action complete?—Verify repair— Step Action Value(s) Yes No

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–311
DIAGNOSTIC TROUBLE CODE (DTC) P1345 (SYMPTOM CODE A)
(FLASH CODE 45) CAMSHAFT SPEED MALFUNCTION
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The pump camshaft sensor is a magnet with a coil. It
uses to combine with the pulser. The pulser is attached
main shaft in the pump. It likes a gear shape.
The pump camshaft sensor is attached to the pump
control unit (PSG). The signal of pump camshaft speed
is sent via the CAN-bus from the PSG to ECM.
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 “Pump Speed” display on the Tech2 while moving
connectors and wiring harnesses. A change in the
display will indicate the location of the fault.
Flash
CodeCode Symptom
CodeMIL DTC Name DTC Setting Condition Fail-Safe (Back Up)
45 P1345 A ON Camshaft Speed Malfunction The PSG (pump control unit)
is re co gnize d inco rrect ca m-
sha ft spe ed signa l.No fa il-sa fe fun ctio n.

6E–312 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1345 (Symptom Code A) (Flash Code 45)
Camshaft Speed 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 P1345 (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 P1345 (Symptom Code A) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4
4 1. Using the Tech 2, ignition “On” and engine “Off”.
2. Monitor the “Pump Speed” in the data display.
Does the Tech 2 indicate correct “Pump Speed”
depending on engine speed?—Go to Step 6Go to Step 5
5 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 9
6 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 7
7 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 8Go to Step 9
8 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—
9 Replace the injection pump assembly.
Is the action complete?—Verify repair—

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–313
DIAGNOSTIC TROUBLE CODE (DTC) P1520 (SYMPTOM CODE A)
(FLASH CODE 47) NEUTRAL SWITCH ON ERROR
DIAGNOSTIC TROUBLE CODE (DTC) P1520 (SYMPTOM CODE B)
(FLASH CODE 47) NEUTRAL SWITCH OFF ERROR
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The ECM monitors the neutral switch (A/T: N or P
position switch in inhibitor switch) signal on the feed
terminal to the ECM. If the neutral switch with
malfunction, DTC P1520 (Symptom Code A) or P1520(Symptom Code B) will be stored.Diagnostic Aids
An intermittent may be caused by the following:
Poor connections.
Flash
CodeCode Symptom
CodeMIL DTC Name DTC Setting Condition Fail-Safe (Back Up)
47 P1520 A ON Neutra l Switch ON Error Neutra l switch signa l is input-
te d “On” thre e times co nsecu-
tively under driving
conditio ns.No fa il-sa fe fun ctio n.
B ON Neutra l Switch OFF Erro r Neutra l switch signa l is input-
te d “Off” three time s co nse cu-
tively under driving
conditio ns.

6E–314 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
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, andpoor terminal to wire connection.
Damaged harness-Inspect the wiring harness for
damage. If the harness appears to be OK, observe
the “Neutral Switch” display on the Tech2 while
moving connectors and wiring harness related to the
sensor.
Diagnostic Trouble Code (DTC) P1520 (Symptom Code A) (Flash Code 47)
Neutral Switch ON Error
Diagnostic Trouble Code (DTC) P1520 (Symptom Code B) (Flash Code 47)
Neutral Switch OFF Error
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 P1520 (Symptom Code A) or P1520
(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 P1520 (Symptom Code A) or P1520
(Symptom Code B) stored in this ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–315
4 Check for poor/faulty connection at the neutral switch
(inhibitor switch) 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 neutral switch (inhibitor
switch).
1. Ignition “Off”, engine “Off”.
2. Remove the neutral switch connector (inhibitor
switch connector) at the transmission.
3. Check the neutral switch (P range N range
switch).
Was the DVM indicated specified value?
Neutral (P or
N): Continuity
Other than
neutral (P or
N): No
continuity Go to Step 6Replace neutral
switch (inhibitor
switch) and
verify repair Step Action Value(s) Yes No
87 C-57
E-11M/TE-12
23
8E-51A/T
E-11 E-12M/T
123654
78109
8
32
A/T