2007 ISUZU KB P190 ECU

Engine Management – V6 – Diagnostics Page 6C1-2–105

Circuit Description
The engine control module (ECM) uses information from the crankshaft position (CKP) sensor and the camshaft position
(CMP) sensor to determine when an engine misfire is occurring. By monitoring variations in the crankshaft rotation
speed for each cylinder, the ECM is able to detect individual misfire events. A misfire rate that is high enough can cause
3-way catalytic converter damage. The malfunction indicator lamp (MIL) will flash ON and OFF when the conditions for
catalytic converter damage are preset. DTCs P0301 – P0306 correspond to cylinders 1 to 6. If the ECM is able to
determine that a specific cylinder is misfiring, the DTC for that cylinder sets.
Conditions for Running the DTC
• DTCs P0121, P0122, P0123, P0221, P0222, P0223, P0335, P0336, or P0338 are not set.
• The engine speed is between 400 – 7,000 rpm and steady.
• The delivered torque signal is more than 10 percent at idle with the transmission in neutral.
• The delivered torque signal is between 10 – 30 percent with the transmission in drive.
• The intake air temperature (IAT) is more than –30° C.
• The engine run time is more than 45 seconds.
• The fuel level is more than 12 percent.
• The torque management is not active.
• DTCs P0301, P0302, P0303, P0304, P0305, and P0306 run continuously when the above conditions exist for at
least 1,000 engine revolutions.
Conditions for Setting the DTC
• The ECM detects a crankshaft rotation speed variation indicating a single cylinder misfire rate sufficient to cause
emissions levels to exceed mandated standards.
• The condition exists for more than 4 seconds.
Action Taken When the DTC Sets
• The control module activates the MIL on the second ignition cycle that the diagnostic runs and fails.
• The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic
fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the
second consecutive ignition cycle, the control module records the operating conditions at the time of the failure.
The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
• The ECM turns OFF the malfunction indicator lamp (MIL) after four consecutive ignition cycles that the diagnostic
runs and does not fail.
• A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
• A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission
related diagnostic.
• Use Tech 2 to clear the MIL and the DTC.
Additional Information
• A misfire DTC could be caused by an excessive vibration from sources other than the engine. Check for the
following possible sources:
− Tyre or wheel out of round or balance
− Variable thickness brake rotor or drum
− Drive shaft not balanced
− Certain rough road conditions

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Engine Management – V6 – Diagnostics Page 6C1-2–113

• DTCs P0341, P0342 and P0343 ran and passed.
• The engine is cranking or running.
• The ECM detects a valid CMP signal.
DTC P0337 and P0338
Runs continuously once the following conditions are met:
• DTCs P0341, P0342 and P0343 ran and passed.
• The engine is cranking or running.
• The ECM detects a valid CMP signal.
Conditions for Setting the DTC
DTC P0335
The ECM does not detect a signal from the CKP sensor for 5 seconds.
DTC P0336
The ECM loses the crankshaft reference position and has to re-synchronise the crankshaft to camshaft one or more
times during six consecutive crankshaft revolutions.
DTC P0337
The ECM detects less than 58 reference signal pulses from the CKP sensor in the last eight consecutive crankshaft
revolutions.
DTC P0338
The ECM detects more than 58 reference signal pulses from the CKP sensor in the last eight consecutive crankshaft
revolutions.
Conditions for Clearing DTC
The CKP sensor circuit DTCs are Type B DTCs. Refer to 1.4 Diagnostic Trouble Codes in this Section, for action
taken when a Type B DTC sets and conditions for clearing Type B DTCs.
Additional Information
• Refer to 6C1-1 Engine Management – V6 – General Information for details of the CKP sensor operation.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• If the ECM has stored and learned the camshafts reference position, the ECM will utilise the camshaft position
(CMP) sensor signal in place of the CKP signal when there is fault condition in the CKP circuit. This will enable the
engine to operate in a limp mode when there is a CKP circuit fault condition.
• During a limp mode, the following DTCs may set and should be ignored.
• DTC P0324 – Knock Sensor Module Performance
• DTC P01011 – Intake Camshaft Position Actuator Park Position Bank 1
• The following fault condition may trigger DTC P0338:
• Fault condition in the CMP sensor circuits.
• Misaligned CKP sensor reluctor wheel or incorrect reluctor wheel installation.
• Excessive crankshaft end play that alters the alignment of the reluctor wheel.
• Obstruction between the CKP sensor and the reluctor wheel.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to 8A Electrical -
Body and Chassis for information on electrical fault diagnosis.

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Engine Management – V6 – Diagnostics Page 6C1-2–122

P0158, P0159, P0160, P0161, P0221, P0222, P0223, P0300, P0301-P0306, P0443, P0458, P0459, P0496,
P167A, P167B, P2096, P2097, P2098, P2099, P2100, P2101, P2107, P2119, P2122, P2123, P2127, P2128,
P2138, P2176, P2177, P2178, P2179, P2180, P2187, P2188, P2189, P2190, P2195, P2196, P2197, P2198,
P2232, P2235, P2237, P2240, P2243, P2247, P2251, P2254, P2270, P2271, P2272, P2273, P2297, P2298,
P2626, and P2629.
• The engine speed is 1,040 – 3,000 rpm.
• The air flow into the engine is between 7.0 – 16.0 g/s and not changing more than 3.0 g/s
• The engine intake air temperature (IAT) at engine start-up is more than –30° C.
• The engine is operating for more than 7 minutes.
• The engine is operating in Closed Loop.
• The calculated TW C temperature is between 500 – 750° C and steady.
• The above conditions exist for approximately 17 minutes.
• DTCs P0420 and P0430 run once a drive cycle. The ECM will attempt to run this diagnostic up to three times a
drive cycle.
Conditions for Setting the DTC
The ECM determines that the catalyst efficiency has degraded below a calibrated threshold for more than 4 seconds.
Action Taken When the DTC Sets
• The control module activates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that
the diagnostic runs and fails.
• The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic
fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the
second consecutive ignition cycle, the control module records the operating conditions at the time of the failure.
The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the DTC
The EVAP Purge Solenoid Valve Control Circuit DTCs are Type B DTCs. Refer to 1.4 Diagnostic Trouble Codes in
this Section, for action taken when a Type B DTC sets and conditions for clearing Type B DTCs.
P0420 or P0430 Diagnostic Table
Step Action Yes No
1
Has the Diagnostic System Check been completed? Go to Step 2 Refer to
4.4 Diagnostic
System Check in this Section
2 Are any other DTCs set? Go to the
appropriate DTC
Table in this Section Go to Step 3
3 1 Inspect for the following conditions:
• The catalytic converter is an original equipment part.
• Inspect the exhaust system for leaks, damage, loose or
missing hardware in the area from the converter to the
heated oxygen sensor 2.
• The HO2S 2 is secure and the wiring is not damaged or
contacting the exhaust.
Did you find and correct the condition? Go to Step 5 Go to Step 4

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Engine Management – V6 – Diagnostics Page 6C1-2–140

Circuit Description
The engine control module (ECM), the powertrain interface module (PIM) and the immobiliser control unit (ICU) are
integral parts of the vehicle immobiliser system. The immobiliser system authenticates the security code programmed
into each of these modules to prevent unauthorised vehicle operation. This authentication process includes the following
steps:
1 At predetermined situations, the ICU sends a security code to the PIM.
2 W hen the ignition is switched ON, the PIM receives and compares this security code from the ICU against the security code programmed into the PIM.
3 Once the PIM receives the correct security code from the ICU, it sends a security code to the ECM.
4 The ECM receives and compares this security code from the PIM against the security code programmed into the ECM.
5 The authentication process is complete once the ECM receives the correct security code from the PIM within the specified time frame.
6 The ECM allows normal vehicle operation.
NOTE
If any of these authentication processes fail, the
vehicle will not start and DTCs will set. For further
information on the immobiliser system, refer to
11A Immobiliser.
Conditions for Running the DTC
Conditions for running the DTC are:
• The ignition is switched on.
• The ignition voltage is 10.0 – 16.0 V.
Conditions for Setting the DTC
P0513
The ECM receives an incorrect response from the PIM during the immobiliser authentication process.
P0633
An attempt is made to start the engine before the immobiliser function has been programmed into a new PIM.
P1629
The ECM has not received a fuel enable password from the ICU.
P1632
The ECM receives an incorrect response from the PIM during the immobiliser authentication process.
P1677
An attempt is made to start the vehicle after the ECM was reset.
P1678
The ECM does not receive a valid response from the PIM when an attempt is made to start the engine.
P1679
The ECM receives a message from the PIM stating that it can't authenticate to the ICU.

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Engine Management – V6 – Diagnostics Page 6C1-2–149

Step Action Yes
No
9 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does any of the ECM system voltage DTCs fail this ignition cycle? Go to Step 2 Go to Step 10
10 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, check the system for correct operation.
7.34 DTC P0601, P0602, P0604 or P0606
DTC Description
This diagnostic procedure supports the following DTCs:
• DTC P0601 – Replace Electronic Control Unit (ECU)
• DTC P0602 – Program Electronic Control Unit (ECU)
• DTC P0604 – Replace Electronic Control Unit (ECU)
• DTC P0606 – Replace Electronic Control Unit (ECU)
Circuit Description
The engine control module (ECM) is the control centre of the engine management system. The programming and
calibration needed by the ECM to control the functionality of the engine management system are stored in the ECM read
only memory (ROM).
An ECM internal circuit, programming or memory fault DTC sets if there is an internal microprocessor integrity fault
condition with the ECM or if the ECM is not programmed.
Conditions for Running the DTC
DTC P0601
Runs once when the checksum calculation at power down is completed in the last ignition cycle.
DTC P0602 and P0606
Runs continuously when the ignition is switched on with the engine not running.
DTC P0604
Runs once when the read / write test at power-down is completed in the last ignition cycle.
Conditions for Setting the DTC
DTC P0601
The ECM detects an incorrect ROM checksum for greater than 30 seconds.
DTC P0602
The ECM programming is incomplete.
DTC P0604
The ECM detects an error in the RAM for 6 seconds.

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Engine Management – V6 – Diagnostics Page 6C1-2–165

Step Action Yes
No
10 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does DTC P0850 fail this ignition cycle? Go to Step 2 Go to Step 11
11 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, check the system for correct operation.
7.43 DTC P1648
DTC Descriptor
This diagnostic procedure supports DTC P1648 – W rong Security Code Entered.
Circuit Description
Tech 2 is used to program the engine control module (ECM). Before any programming, a security code must be entered
into Tech 2. The ECM will check if the code entered is correct before continuing. If the security code is incorrect, DTC
P1648 sets.
Conditions for Running the DTC
Conditions for running the DTC are:
• The ignition is switched on.
• The ignition voltage is 10.0 – 16.0 V.
Conditions for Setting the DTC
An incorrect security code is entered into Tech 2 when attempting to program the ECM.
Action Taken When the DTC Sets
W hen the DTC sets, the malfunction indicator lamp (MIL) is not displayed.
Conditions for Clearing the DTC
The immobiliser security code is a Type ‘C’ DTC. Refer to 1.4 Diagnostic Trouble Codes in this Section, for action
taken when a Type ‘C’ DTC sets and conditions for clearing Type ‘C’ DTCs.
Additional Information
• Refer to 6C1-1 Engine Management –V6 – General Information for details of the ECM operation.
• Refer to 6C1-3 Engine Management –V6 – Service Operations for details on resetting the ECM.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to 8A Electrical -
Body and Chassis for information on electrical fault diagnosis.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.

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Test Description
The following numbers refer to the step numbers in the diagnostic table:
4 This step tests the ECM ground circuits and supply voltage.
DTC P1648 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.4 Diagnostic
System Check in this Section
2 1 Switch off the ignition for 30 seconds.
2 Using Tech 2, select the DTC display function.
NOTE
Do not attempt to perform any Tech 2 function that
requires the ECM security code to be entered.
Does DTC P1648 fail this ignition cycle? Go to Step 4 Go to Step 3
3 Using Tech 2, attempt a programming function that requires the ECM
security code to be entered. Refer to 6C1-3 Engine Management –V6
– Service Operations for details on resetting the ECM.
Has the programming function been successfully performed? System OK Go to Step 4
4 1 Test all ECM ground circuits for a high resistance or an open
circuit fault condition. Refer to 8A Electrical - Body and Chassis
for information on electrical fault diagnosis.
2 Test the ECM ignition supply voltage circuit for a high resistance, open circuit or short to ground fault condition. Refer
to 8A Electrical - Body and Chassis for information on electrical
fault diagnosis.
Has any fault been found and rectified? Go to Step 6 Go to Step 5
5 Replace the ECM. Refer to 6C1-3 Engine Management –V6 – Service
Operations for details on replacing the ECM.
Has the repair been completed? Go to Step 6 —
6 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
Does DTC P1648 fail this ignition cycle? Go to Step 2 Go to Step 7
7 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, clear all DTCs and check the system for correct operation.
7.44 DTC P1668, P2500 or P2501
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P1668 – Generator L Terminal Circuit Malfunction
• DTC P2500 – Generator L Terminal Low Voltage
• DTC P2501 – Generator L Terminal High Voltage

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Engine Management – V6 – Diagnostics Page 6C1-2–170

Step Action Yes
No
7 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, check the system for correct operation.
7.46 DTC P2096 or P2098
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P2096 Post Catalyst O2 Sensor Fuel Trim Below Lower Limit (Bank 1)
• DTC P2098 Post Catalyst O2 Sensor Fuel Trim Below Lower Limit (Bank 2)
Circuit Description
The wide band heated oxygen sensor 1 measures the amount of oxygen in the exhaust system and provides more
information than the switching style HO2S2. The wide band sensor consists of an oxygen sensing cell, an oxygen
pumping cell, and a heater. The exhaust gas sample passes through a diffusion gap between the sensing cell and the
pumping cell. The engine control module (ECM) supplies a voltage to the HO2S and uses this voltage as a reference to
the amount of oxygen in the exhaust system. An electronic circuit within the ECM controls the pump current through the
oxygen pumping cell, maintaining a constant voltage in the oxygen sensing cell. The ECM monitors the voltage variation
in the sensing cell and attempts to keep the voltage constant by increasing or decreasing the amount of current flow, or
oxygen ion flow, to the pumping cell. By measuring the amount of current required to maintain the voltage in the sensing
cell, the ECM can determine the concentration of oxygen in the exhaust. The HO2S voltage is displayed as a lambda
value. A lambda value of 1 is equal to a stoichiometric air fuel ratio of 14.7:1. Under normal operating conditions, the
lambda value will remain around 1. W hen the fuel system is lean, the oxygen level will be high and the lambda signal
will be high or more than 1. W hen the fuel system is rich, the oxygen level will be low, and the lambda signal will be low
or less than 1. The ECM uses this information to maintain the correct air / fuel ratio.
Fuel trim biasing is used by the ECM to keep the post catalyst HO2S voltage within a range of 580 – 665 mV as
possible. This allows optimal catalyst efficiency under light load conditions, such as at idle or a steady cruise. The ECM
constantly monitors how lean or rich the fuel trim bias is commanded. If the ECM detects that the fuel trim bias is
commanded lean for more than a calibrated amount, DTC P2096 or P2098 sets.
Conditions for Running the DTC
• Before the ECM can report DTC P2096 or P2098 failed, DTCs P0030, P0031, P0032, P0041, P0050, P0051,
P0052, P0101, P0131, P0132, P0135, P0137, P0138, P0140, P0141, P0151, P0152, P0155, P0157, P0158,
P0160, P0161, P2231, P2234, P2237, P2240, P2243, P2247, P2251, P2254, P2270, P2271, P2273, P2626, and
P2629 must run and pass.
• The engine is operating for more than 2 seconds.
• The post catalyst fuel trim control is enabled.
• The front and rear HO2S are in Closed Loop.
• DTCs P2096and P2098 run continuously once the above conditions are met for more than 40 seconds.
Conditions for Setting the DTC
The post catalyst fuel trim correction factor is biased lean by more than 3 percent of the HO2S lambda value for more
than 4 seconds.
Action Taken When the DTC Sets
• The ECM activates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the
diagnostic runs and fails.
• The ECM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the
control module stores this information in the Failure Records. If the diagnostic reports a failure on the second
consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The
control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

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