sensor ISUZU KB P190 2007 Workshop Repair Manual

ENGINE DRIVEABILITY AND EMISSIONS 6E–161
6 Using the DVM and check the O2 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 O
2 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 O
2 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 13
7 1. Using the Tech 2, ignition “On” and engine “On”. 2. Monitor the “Manifold Absolute Pressure” in thedata display.
Does the Tech 2 indicate correct “Manifold Absolute
Pressure” in accordance with engine speed or
acceleration? — Go to Step 9Go to Step 8
8 Remove the MAP sensor and check for the following conditions.
• Objects blocking the air cleaner.
• Objects blocking the MAP sensor.
• Objects blocking the throttle valve.
• Vacuum leaking at intake duct.
• Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found? — Verify repair Go to Step 9
9 1. Using the Tech 2, ignition “On” and engine “On”. 2. Select the “Miscellaneous Test” and perform the“IAC Control” in the “IAC System”.
3. Operate the Tech 2 in accordance with procedure.
Was the engine speed changed, when the IAC valve
is operating step by step? — Go to Step 11Go to Step 10
Step
Action Value(s) Yes No
J2-6J2-21
Breaker Box
E-77
21
ΩΩ
1
2
21
6C56(J2) E77

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6E–162 ENGINE DRIVEABILITY AND EMISSIONS
10 Check for the following conditions. • Objects blocking the IAC valve.
• Objects blocking the throttle valve.
• Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found? — Verify repair Go to Step 11
11 Check for injector for the affected bank. Refer to “Injector Coil Test & Injector Balance Test
Procedure” 6E-98 page .
Was the injector operation correct? —Go to Step 12Refer to
Injector
Coil Test & Injector
Balance Test Procedure
12 Check for fuel pressure. Refer to “Fuel System Diagnosis” 6E-108 page.
Was the fuel pressure correct? — Go to Step 13Refer to
Fuel
System
Diagnosis
13 Replace the O
2 sensor.
Was the problem solved? — Verify repair Go to Step 14
14 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 15
15 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

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ENGINE DRIVEABILITY AND EMISSIONS 6E–163
DIAGNOSTIC TROUBLE CODE (DTC) P0135 O2 SENSOR HEATER CIRCUIT
(BANK 1 SENSOR 1)
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
Heated oxygen sensors are used to minimize the
amount of time required for “Closed Loop” fuel control
operation and to allow accurate catalyst monitoring. The
oxygen sensor heater greatly decreases the amount of
time required for fuel control sensors Bank 1 HO2S 1 1
to become active. Oxygen sensor heaters are required
by catalyst monitor sensors Bank 1 HO2S 2 to maintain
a sufficiently high temperature which allows accurate
exhaust oxygen content readings further from the engine.
The engine control module (ECM) will run the heater
test only after a cold start (determined by engine coolant
and intake air temperature at the time of start-up) and
only once during an ignition cycle. When the engine is
started the ECM will monitor the HO2S voltage. When
the HO2S voltage indicates a sufficiently active sensor,
the ECM looks at how much time has elapsed since
start-up. If the ECM determines that too much time was
required for the Bank 1 HO2S 1 to become active, a
Diagnostic Trouble Code P0135 will set.
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0135 A O
2 SensorHeater Circuit (Bank 1 Sen-
sor 1) 1. No DTC relating to MAP sensor and ECT
sensor.
2. Engine coolant temperature is more than 60 deg. C.
3. Engine run time is longer than 20 seconds.
4. MAP sensor output is more than 70kPa.
5. O
2 sensor bank 1 heater current more than
10mA. No fail-safe function.

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6E–164 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Aids
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.
• Damaged harness - Inspect the wiring harness for damage; shorts to ground, shorts to battery positive
and open circuits.
Diagnostic Trouble Code (DTC) P0135
O
2 Sensor Heater Circuit (Bank 1 Sensor 1)
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 P0135 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 P0135 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 O
2 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 O
2 sensor.
Was the problem found? — Go to Step 11Go to Step 6
6 Using the DVM and check the O
2 sensor.
1. Ignition “Off”, engine “Off”.
2. Disconnect O
2 sensor connector
3. Measure the resistance of heater.
Was the tester indicated specified value?
Approximately
12.5 Ω at 20°C Go to Step 7Go to Step 11
3431
C56(J2) E77
34
1234
O2 Sensor

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ENGINE DRIVEABILITY AND EMISSIONS 6E–165
7 Using the DVM and check the heater power supplycircuit for the affected cylinder.
1. Ignition “On”, engine “Off”.
2. Disconnect the O
2 sensor connector.
3. Check the circuit for open circuit.
Was the DVM indicated specified value?
10 - 14.5V Go to Step 9Go to Step 8
8 Repair the open or short to ground circuit between the “O
2 Sensor” fuse (10A) and O2 sensor.
Is the action complete? — Verify repair —
9 Using the DVM and check the heater ground 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 O
2 sensor 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 O
2 sensor connector 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
4
V
E77
J2-31Breaker BoxE-77
3
ΩΩ
331E56(J2)E77

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6E–166 ENGINE DRIVEABILITY AND EMISSIONS
10 Using the DVM and check the heater ground circuit.1. Ignition “On”, engine “Off”.
2. Disconnect the O
2 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 12
11 Replace the O
2 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
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
3
V
E77

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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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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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