2007 ISUZU KB P190 DTC CHECK

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
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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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ISUZU KB P190 2007

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
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ISUZU KB P190 2007

ENGINE DRIVEABILITY AND EMISSIONS 6E–181
Diagnostic Aids
An intermittent may be caused by a poor connection,
rubbed-through wire insulation or a wire broken inside
the insulation. Check for:
• Poor connection - Inspect the ECM harness and connectors for improper mating, broken locks,
improperly formed or damaged terminals, and poor
terminal-to-wire connection. • Damaged harness - Inspect the wiring harness for
damage; shorts to ground, shorts to battery positive
and open circuits. If the harness appears to be OK,
disconnect the ECM, turn the ignition on and observe
a voltmeter connected to the 58X reference circuit at
the ECM harness connector while moving connectors
and wiring harnesses related to the ECM. A change
in voltage will indicate the location of the fault.
Diagnostic Trouble Code (DTC) P0336
Crankshaft Position Sensor Circuit Range/performance (58x)
Diagnostic Trouble Code (DTC) P0337
Crankshaft Position Sensor Circuit Low Input (58x)
Step Action 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 P0336 or P0337 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 P0336 or P0337 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 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 i s f o u n d , r e p a i r a s n e c e s s a r y.
Was the problem found? — Verify repair Go to Step 6
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ISUZU KB P190 2007

6E–186 ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0351 IGNITION 1 CONTROL CIRCUIT
DIAGNOSTIC TROUBLE CODE (DTC) P0352 IGNITION 2 CONTROL CIRCUIT
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The ignition control circuit provides a zero volt or a 5 volt
signal to the ignition control module. The normal circuit
voltage is zero volts. When the module receives the 5
volt signal from the ECM, it provides a ground path for
the B+ voltage supplied to the ignition primary coil.
When the ECM turns off the 5 volts to the module, the
module will remove the ground path of the ignition
primary coils; causing the magnetic field produces a
voltage in the secondary coils which fires the spark
plug. The circuit between the ECM and the ignition control
module is monitored for an open circuit, short to voltage,
and short to ground. When the ECM detects a problem
in the ignition control circuit, it will set DTC P0351 or
P0352.
Diagnostic Aids
Check for the following conditions:
• Poor connection at the ECM - Inspect the harness connectors for backed-out terminals, improper
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0351 A Ignition 1 Control Circuit #1 or #4cylinder ignition signals are not
detected consecutively. No fail-safe function.
P0352 A Ignition 2 Control Circuit #2 or #3 cylinder ignition signals are not
detected consecutively.

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ENGINE DRIVEABILITY AND EMISSIONS 6E–187
mating, broken locks, improperly formed or damaged
terminals, and poor terminal-to-wire connections.
• Damaged harness - Inspect the wiring harness for damage; Open circuits, shorts to ground, or shorts to
Voltage. If the harness appears to be OK, observe the Tech 2 display related to DTC P0351 or P0352
while moving the connector and wiring related to the
ignition system. A change in the display will indicate
the location of the fault.
Diagnostic Trouble Code (DTC) P0351 Ignition 1 Control Circuit
Diagnostic Trouble Code (DTC) P0352 Ignition 2 Control Circuit
Step Action 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 P0351 or P0352 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 P0351 or P0352 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 ignition coil module 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 ignition coil module. Was the problem found? — Go to Step 12Go to Step 6
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ENGINE DRIVEABILITY AND EMISSIONS 6E–191
DIAGNOSTIC TROUBLE CODE (DTC) P0443 EVAPORATIVE (EVAP) EMISSION CONTROL SYSTEM PURGE CONTROL CIRCUIT
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The Engine Control Module (ECM) controls the
Evaporative Emission (EVAP) Canister Purge Solenoid
Valve through the use of a control (ground) circuit. If the
ECM commands the Purge solenoid to maximum duty
cycle (100%) but the voltage remains High (12 Volts);
or, if the ECM commands the Purge solenoid to
minimum duty cycle (0%) but the voltage remains Low
(0 volts), then DTC P0443 will set.
Diagnostic Aids
• Poor connections, or a damaged harness - Inspect the harness connectors for: backed-out terminals,
improper mating or damaged terminals. Also check
for open circuits, shorts to ground, and shorts to
voltage.
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0443 B EVAP Emission Control System Purge Control Circuit EVAP purge solenoid circuit open, short to
ground or short to voltage circuit. No fail-safe function.

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