ISUZU KB P190 2007 Workshop Repair Manual

ENGINE DRIVEABILITY AND EMISSIONS 6E–171
9 Using the DVM and check the injector signal circuit forthe affected cylinder.
Breaker box is available:
1. Ignition “Off”, engine “Off”.
2. Install the breaker box as type A. (ECM disconnected) Refer to 6E-88 page.
3. Disconnect the injector connector for the affected cylinder.
4. Check the circuit for open or short to ground circuit.
Was the problem found?
—Repair faulty
harness and verify repair Go to Step 10
Step
Action Value(s) Yes No
J1-9Breaker Box2
ΩΩ
No. 1 Cylinder
E-6
J1-22Breaker Box2
ΩΩ
No. 2 Cylinder E-7
J1-8Breaker Box
ΩΩ
No. 3 Cylinder
E-82
J1-11Breaker Box2
ΩΩ
No. 4 Cylinder E-9

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ISUZU KB P190 2007

6E–172 ENGINE DRIVEABILITY AND EMISSIONS
9Breaker box is not available:
1. Ignition “Off”, engine “Off”.
2. Disconnect the injector connector for the affected cylinder and ECM connector.
3. Check the circuit for open or short to ground circuit.
Was the problem found?
—Repair faulty
harness and verify repair Go to Step 10
Step
Action Value(s) Yes No
E-60(J1)
E-6
9
2
No.1 Cylinder
E-60(J1) E-7
22
2
No.2 Cylinder
E-60(J1) E-8
8
2
No.3 Cylinder
E-60(J1) E-9
11
2
No.4 Cylinder

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ISUZU KB P190 2007

ENGINE DRIVEABILITY AND EMISSIONS 6E–173
10 Using the DVM and check the injector signal circuit.1. Ignition “On”, engine “Off”.
2. Disconnect the injector connector for the affected cylinder.
3. Check the circuit for short to voltage circuit.
Was the DVM indicated voltage?
—Repair faulty
harness and verify repair Go to Step 12
11 Replace the injector for the affected cylinder. 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
13 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 —
Step
Action Value(s) Yes No
V
2
E-6
No.1 Cylinder
V
2
E-7
No.2 Cylinder
V
2
E-8
No.3 Cylinder
V
2
E-9
No.4 Cylinder

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6E–174 ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0325 KNOCK SENSOR (KS) MODULE CIRCUIT
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The knock sensor (KS) system is used to detect engine
detonation. The knock sensor produced an AC voltage
signal. The knock sensor sends this signal to the ECM.
The amplitude and the frequency of the AC voltage
signal depends upon the knock level being detected.
The ECM will then retard the spark timing based on the signals from the Knock Sensor.Diagnostic Aids
Correct any abnormal engine noise before using the
diagnostic table.
Check for an open circuit.
Diagnostic Trouble Code (DTC) P0325 Knock Sensor Module Circuit
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0325 B Knock Sensor Module Circuit 1. No DTC relating to MAP sensor.
2. Engine coolant temperature is more than 50 deg. C.
3. Engine speed is more than 1600rpm.
4. Knock sensor filter module integrated cir- cuit malfunction. ECM retards ignition timing 4 deg. C
.
StepAction 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

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ISUZU KB P190 2007

ENGINE DRIVEABILITY AND EMISSIONS 6E–175
2 1. Connect the Tech 2. 2. Review and record the failure information.
3. Select “F0: Read DTC Infor By Priority” in “F0: Diagnostic Trouble Code”.
Is the DTC P0325 stored as “Present Failure”? — Go to Step 3Refer to
Diagnostic Aids and Go to Step
3
3 1. Using the Tech2, ignition “On” and engine “Off”. 2. Select “Clear DTC Information” with the Tech2 andclear the DTC information.
3. Operate the vehicle and monitor the “F5: Failed This Ignition” in “F2: DTC Information”.
Was the DTC P0325 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 knock 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 knock sensor. Was the problem found? — Go to Step 10Go to Step 6
6 Listen to the engine noise while raising and lowering the engine speed.
Is a knock or audible noise present? — Go to Step 7Go to Step 8
7 Repair the mechanical engine problem or a loose bracket or component.
Is the action complete? — Verify repair —
Step
Action Value(s) Yes No
32
3
E-60(J1)
E-84

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6E–176 ENGINE DRIVEABILITY AND EMISSIONS
8 Using the DVM and check the knock sensor circuit.Breaker box is available:
1. Ignition “Off”, engine “Off”.
2. Install the breaker box as type A. (ECM disconnected) Refer to 6E-88 page.
3. Disconnect the knock sensor.
4. Check the circuit for open circuit.
Was the problem found?
Breaker box is not available: 1. Ignition “Off”, engine “Off”.
2. Disconnect the knock sensor connector and ECM connector.
3. Check the circuit for open circuit.
Was the problem found?
—Repair faulty
harness and verify repair Go to Step 9
9 Substitute a known good knock sensor and recheck. Was the problem solved? — Go to Step 10 Go to Step 11
10 Replace the knock sensor. Was the problem solved? — Verify repair Go to Step 11
11 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 12
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 —
Step
Action Value(s) Yes No
J1-3J1-32
Breaker Box
E-8421
Ω
Ω
3
E-60(J1)
E-84
322
1

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ISUZU KB P190 2007

ENGINE DRIVEABILITY AND EMISSIONS 6E–177
DIAGNOSTIC TROUBLE CODE (DTC) P0327 KNOCK SENSOR (KS) CIRCUIT
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The ECM uses the Knock Sensor (KS) in order to detect
engine detonation. This allows the ECM to retard the
Ignition Control (IC) spark timing based on the KS signal
the ECM receives. The knock sensors produce an AC
signal that rides on the 1.3 volts DC. The signal’s
amplitude and frequency are dependent upon the
amount of the knock being experienced.
The ECM determines whether the knock is occurring by
comparing the signal level on the KS circuit with a
voltage level on the noise channel. The normal engine
noise varies depending on the engine speed and load.
Then the ECM determines that an abnormally high
noise channel voltage level is being experienced, a
Diagnostic Trouble Code P0327 sets.
Diagnostic Aids
Check for the following conditions:
A poor connection at the ECM. Inspect the knock
sensor and the ECM connectors for: , broken locks,
improperly formed or damaged terminals.
• Backed out terminals
• Broken locks
• Improperly formed or damaged terminals
Also, check the wiring harness for: shorts to ground,
shorts to battery positive, and open circuits.
• A misrouted harness. Inspect the knock sensor harness in order to ensure that it is not routed too
close to high voltage wires such as spark plug leads.
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0327 A Knock Sensor Circuit 1. No DTC relating to MAP sensor.
2. Engine coolant temperature is more than 50 deg. C.
3. Engine speed is more than 1600rpm.
4. Knock sensor harness short to ground or short to voltage circuit. ECM retards ignition timing 4 deg. C
.

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6E–178 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0327 Knock Sensor Circuit
StepAction 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 By Priority” in “F0: Diagnostic Trouble Code”.
Is the DTC P0327 stored as “Present Failure”? — Go to Step 3Refer to
Diagnostic Aids and Go to Step
3
3 1. Using the Tech2, ignition “On” and engine “Off”. 2. Select “Clear DTC Information” with the Tech2 andclear the DTC information.
3. Operate the vehicle and monitor the “F5: Failed This Ignition” in “F2: DTC Information”.
Was the DTC P0327 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 knock 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 knock sensor. Was the problem found? — Go to Step 9Go to Step 6
6 Using the DVM and check the knock sensor circuit. 1. Ignition “Off”, engine “Off”.
2. Disconnect the knock sensor connector and ECM connector.
3. Check the circuit for short to sensor ground or ground circuit.
Was the problem found?
—Repair faulty
harness and verify repair Go to Step 7
32
3
E-60(J1)
E-84
E-84
2
1

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ISUZU KB P190 2007

ENGINE DRIVEABILITY AND EMISSIONS 6E–179
7 Using the DVM and check the knock sensor circuit.1. Ignition “On”, engine “Off”.
2. Disconnect the knock sensor connector.
3. Check the circuit for short to voltage circuit.
Was the DVM indicated voltage?
—Repair faulty
harness and verify repair Go to Step 8
8 Substitute a known good knock sensor and recheck. Was the problem solved? — Go to Step 9Go to Step 10
9 Replace the knock sensor. Was the problem solved? — 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 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 —
Step
Action Value(s) Yes No
VV
E-84
2
1

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6E–180 ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0336 CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT RANGE/PERFORMANCE (58X)
DIAGNOSTIC TROUBLE CODE (DTC) P0337 CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT LOW INPUT (58X)
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The 58X reference signal is produced by the crankshaft
position (CKP) sensor. During one crankshaft
revolution, 58 crankshaft pulses will be produced. The
engine control module (ECM) uses the 58X reference
signal to calculate engine RPM and crankshaft position.
The ECM constantly monitors the number of pulses on the 58X reference circuit. If the ECM receives an
incorrect number of pulses on the 58X reference circuit,
Diagnostic Trouble Code P0336 will set. If the ECM
does not receive pluses on the 58X reference circuit,
Diagnostic Trouble Code P0337 will set.
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0336 B Crankshaft Position Sensor Circuit Range/Performance (58X) 1. Engine is running.
2. Extra or missing pulse is detected consecu- tively. No fail-safe function.
P0337 B Crankshaft Position Sensor Circuit Low Input (58X) No pulse is detected during engine cranking.

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