2007 ISUZU KB P190 engine oil

Engine Management – V6 – Diagnostics Page 6C1-2–119

The ECM applies control voltage to the control circuit of the ignition coil during the calculated dwell period that allows
current flow to the ignition coil primary winding to generate a magnetic flux field. At the appropriate firing point, the ECM
interrupts the control voltage applied to the ignition coil.
Interruption of voltage applied to the control circuit of the ignition coil primary winding induces the transfer of electrical
energy from the ignition coil primary winding to the ignition coil secondary winding, which triggers the ignition coil to
produce a spark at the spark plug.
An ignition coil control circuit DTC sets if the ECM detects a fault condition in the control circuit of an ignition coil.
Conditions for Running the DTC
Run continuously once the following conditions are met:
• The engine is running.
• The engine speed is 480 – 5,000 rpm
• The battery voltage is 10.0 – 16.0 V.
Conditions for Setting the DTC
DTC P0351, P0352, P0353, P0354, P0355 or P0356
The ECM detects an open circuit fault condition in the ignition coil control circuit.
DTC P2300, P2303, P2306, P2309, P2312 or P2315
The ECM detects a short to ground fault condition in the ignition coil control circuit.
DTC P2301, P2304, P2307, P2310, P2313 and P2316
The ECM detects a short to voltage fault condition in the ignition coil control circuit.
Conditions for Clearing the DTC
The ignition coil control circuit DTCs are Type B DTCs. Refer to 1.4 Diagnostic Trouble Codes in this Section, for
action taken when 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 ignition coil operation.
• A short to voltage fault condition damages the ignition coil. Do not replace the ignition until this fault condition is
rectified.
• The ignition coils for each bank of the engine are fused separately. If all DTCs for a single bank are set, there may
be a fault in one of the ignition supply circuits.
• The ignition coils for each bank of the engine have a separate ground connections. If all DTCs for a single bank
are set, there may be a fault in one of the ground circuits.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• 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.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
3 Determines if there is a fault condition in the ignition voltage supply circuit.
5 Determines if there is a fault condition in the ground circuits of the ignition coil.
6 Tests if the ECM is commanding the ignition coil on and off.

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Engine Management – V6 – Diagnostics Page 6C1-2–120

DTC P0351 to P0356, P2300, P2301, P2303, P2304, P2306, P2307, P2309, P2310, P2312,
P2313, P2315 or P2316 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 Start the engine.
3 Using Tech 2, select the DTC display function.
Does DTC P0351, P0352, P0353, P0354, P0355, P0356, P2300,
P2301, P2303, P2304, P2306, P2037, P2309, P2310, P2312, P2313,
P2315 or P2316 fail this ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 1 Disconnect the wiring connector of the appropriate ignition coil.
2 Switch on the ignition with the engine not running.
3 Connect a test lamp between the ignition voltage circuit of the appropriate ignition coil connector and the ECM housing.
Does the test lamp illuminate? Go to Step 4 Go to Step 6
4 Connect a test lamp between a 12 V and each of the ground circuits
of the ignition coil connector.
Does the test lamp illuminate? Go to Step 5 Go to Step 7
5 1 Start the engine.
2 Using a digital multimeter, measure the frequency at the control circuit of the ignition coil.
Does the multimeter display 3 – 20 Hz? Go to Step 9 Go to Step 8
6 Repair the high resistance or open circuit fault condition at the ignition
voltage circuit of the ignition coil. Refer to 8A Electrical - Body and
Chassis for information on electrical wiring repair procedures.
W as the repair completed? Go to Step 11 —
7 Repair the high resistance or open circuit fault condition at the ignition
coil ground circuits. Refer to 8A Electrical - Body and Chassis for
information on electrical wiring repair procedures.
W as the repair completed? Go to Step 11 —
8 Test the appropriate ignition coil control circuit for a high resistance,
open circuit, short to ground or short to voltage fault condition. Refer
to 8A Electrical - Body and Chassis for information on electrical fault
diagnosis.
W as any fault found and rectified? Go to Step 11 Go to Step 10
9

A short to voltage fault condition damages the ignition
coil. Do not replace the ignition until this fault
condition is rectified.
Replace the faulty ignition coil. Refer to 6C1-3 Engine Management –
V6 – Service Operations.
W as the repair completed? Go to Step 11 —

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Engine Management – V6 – Diagnostics Page 6C1-2–121

Step Action Yes No
10 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 11 —
11 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 ignition coil control circuit DTCs fail this ignition
cycle? Go to Step 2 Go to Step 12
12 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.
7.23 DTC P0420 or P0430
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0420 Catalyst System Low Efficiency Bank 1
• DTC P0430 Catalyst System Low Efficiency Bank 2
Circuit Description
To maintain a reasonably low emission level of hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen
(NOx) a 3-way catalytic converter (TW C) is used. The catalyst within the converter promotes a chemical reaction that
oxidizes the HC and CO present in the exhaust gas. This reaction converts the gases into harmless water vapour and
carbon dioxide. The catalyst also reduces the NOx, converting the NOx into nitrogen. The engine control module (ECM)
monitors this process using the post catalyst heated oxygen sensor (HO2S) signal. The post-catalyst HO2S located in
the exhaust stream after the TW C, produces an output signal that indicates the oxygen storage capacity of the catalyst.
The oxygen storage capacity (OSC) determines the ability of the catalyst to convert the exhaust emissions effectively. If
the catalyst is functioning correctly, the post-catalyst HO2S signal will be far less active than the signal produced by the
pre-catalyst HO2S.
To determine OSC, the ECM commands a rich air / fuel mixture until all oxygen is removed from the catalyst. The ECM
then commands a lean air / fuel mixture and monitors the rear heated oxygen sensors to calculate the oxygen storage
capacity. The catalyst is operated in this mode until one of the following conditions occur:
• The oxygen stored in the catalyst exceeds a calibrated threshold, which is determined from the rear HO2S signal.
• The rear HO2S indicates the catalyst to be completely saturated with oxygen, which is determined from the rear
HO2S signal.
If the ECM detects the average OSC is less than a threshold, this DTC sets. This indicates that the TW C oxygen
storage capacity is below a threshold considered acceptable.
Conditions for Running the DTC
• Before the ECM can report, the following DTCs must run and pass:
DTC P0420 or P0430 failed, DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0053,
P0056, P0057, P0058, P0059, P0101, P0102, P0103, P0121, P0122, P0123, P0130, P0131, P0132, P0133,
P0135, P0137, P0138, P0139, P0140, P0141, P0150, P0151, P0152, P0153, P0155, P0157, P0158, P0159,
P0160, P0161, P0221, P0222, P0223, P0335, P0336, P0338, P167A, P167B, P2096, P2097, P2098, P2099,
P2195, P2196, P2197, P2198, P2232, P2235, P2237, P2240, P2243, P2247, P2251, P2254, P2270, P2271,
P2272, P2273, P2297, P2298, P2626, and P2629.
• The following DTCs are not set:
DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0053, P0056, P0057, P0058,
P0059, P0101, P0102, P0103, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0125, P0130, P0131,
P0132, P0133, P0135, P0137, P0138, P0139, P0140, P0141, P0150, P0151, P0152, P0153, P0155, P0157,

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Engine Management – V6 – Diagnostics Page 6C1-2–142

Step Action Yes No
8 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.
7.31 DTC P0521, P0522 or P0523
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0521 – Oil Pressure Sensor Range / Performance
• DTC P0522 – Oil Pressure Sensor Voltage Low
• DTC P0523 – Oil Pressure Sensor Voltage High
Circuit Description
The ECM applies a positive 5 V reference voltage to the engine oil pressure (EOP) sensor through the 5 V reference
circuit and the ground through the low reference circuit.
The EOP sensor provides signal voltage to the ECM that is proportional to the oil pressure generated by the engine oil
pump. The ECM monitors the EOP sensor signal voltage. If the ECM detects a low oil pressure condition, it sends a
serial data communication signal to the instrument cluster to illuminate the check oil warning icon.
The ECM monitors and compares the EOP sensor signal voltage against a specified range. An EOP sensor circuit DTC
sets if the ECM detects the EOP sensor signal voltage is outside the specified range.
Conditions for Running the DTC
DTC P0521, P0522 and P0523 run continuously when the engine is running.
Conditions for Setting the DTC
P0521
The ECM detects engine oil pressure is:
• greater than 800 kPa at idle, or
• engine rpm is greater than 2000 rpm and oil pressure is less than 8 kPa.
P0522
The oil pressure sensor signal voltage is less than 0.2 V for more than 10 seconds.
P0523
The oil pressure sensor signal voltage is more than 4.9 V for more than 10 seconds.
Conditions for Clearing DTC
The EOP sensor circuit DTCs are Type B DTC. 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 EOP sensor operation.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• 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 6C1-2–144

Step Action
Yes No
8 1 Disconnect the ECM wiring connector.
2 Test the EOP sensor low reference circuit for a high resistance and open circuit fault condition. Refer to 8A Electrical - Body
and Chassis for information on electrical fault diagnosis.
NOTE
The EOP sensor shares the low reference circuit with
other sensors. A fault condition in the low reference circuit
may trigger DTCs on sensors that share this circuit. Refer
to 3 W iring Diagrams and Connector Charts in this
Section, to assist diagnosis.
W as any fault found and rectified? Go to Step 11 Go to Step 10
9 Replace the EOP sensor. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 11 —
10 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 11 —
11 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 for the engine oil pressure sensor circuit DTCs s fail
this ignition cycle? Go to Step 2 Go to Step 12
12 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.
7.32 DTC P0532 or P0533
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0532 – A/C Pressure Sensor Voltage Low
• DTC P0533 – A/C Pressure Sensor Voltage High
Circuit Description
The ECM supplies a positive 5 V reference voltage to the air-conditioning (A/C) refrigerant pressure sensor through
reference circuit and the ground through the low reference circuit.
The A/C pressure sensor provides signal voltage to the ECM through the signal circuit that is proportional to the A/C
refrigerant pressure. The ECM monitors the signal voltage of the A/C pressure sensor to determine the refrigerant
pressure.
• The A/C pressure sensor voltage increases as the refrigerant pressure increases.
• W hen the ECM detects the refrigerant pressure exceeds a predetermined value, the ECM activates the cooling
fans to reduce the refrigerant pressure.
• W hen the ECM detects the refrigerant pressure is too high or too low, the ECM disables the A/C clutch to protect
the A/C compressor from damage.

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Engine Management – V6 – Diagnostics Page 6C1-2–151

7.35 DTC P0615, P0616 or P0617
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0615 – Starter Relay Circuit Malfunction
• DTC P0616 – Starter Relay Circuit Low Voltage
• DTC P0617 – Starter Relay Circuit High Voltage
Circuit Description
The engine control relay applies battery voltage to the coil circuit of the starter relay through the ignition circuit. W hen
the ignition switched is turned to the Start position and all the conditions required to enable an engine cranking is met,
the ECM grounds the starter relay control circuit to activate the starter relay. W hen active, the starter relay applies
battery voltage to the starter motor solenoid control circuit to operate the starter motor. Refer to 6D1-2 Starting System –
V6 for information on the cranking system operation.
The ECM monitors the control circuit of the starter relay for conditions that are incorrect for the commanded state. A
starter relay control circuit DTC sets if the ECM detects a fault condition in the starter relay control circuit.
Conditions for Running the DTC
DTCs P0615, P0616 and P0617 run continuously once the following conditions are met:
• The ignition is switched on
• The ignition voltage is 10.0 – 16.0 V.
Conditions for Setting the DTC
The ECM detects a condition that is incorrect for the starter relay commanded state.
Conditions for Clearing the DTC
The starter relay control circuit DTCs are Type C DTCs. Refer to 1.4 Diagnostic Trouble Codes in this Section, for
action taken when Type C DTCs set and conditions for clearing Type C DTCs.
Additional Information
• Refer to 6D1-2 Starting System – V6 for information on the cranking system operation.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• 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.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.
Test Description
The following number refers to the step number in the diagnostic table:
3 A fault condition in the starting system or immobiliser system may trigger this DTC.
DTC P0615, P0616 or P0617 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

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Engine Management – V6 – Diagnostics Page 6C1-2–155

Circuit Description
The ground circuit of the fuel pump relay coil is directly connected to ground. W hen the ignition switch is turned on and
all the conditions required to enable fuel pump operation are met, the ECM applies battery voltage to the fuel pump relay
control circuit to operate the fuel pump. Refer to 6C Fuel System – V6 for further information.
The ECM monitors the control circuit of the fuel pump relay for conditions that are incorrect for the commanded state. A
fuel pump relay control circuit DTC sets if the ECM detects a fault condition in this circuit.
Conditions for Running the DTC
Run continuously once the following conditions are met:
• the ignition is switched on, and
• the ignition voltage is 10.0 – 16.0 V.
Conditions for Setting the DTC
The ECM detects a condition that are incorrect for the fuel pump relay commanded state.
Conditions for Clearing the DTC
The fuel pump relay control circuit DTCs are Type C DTCs. Refer to 1.4 Diagnostic Trouble Codes in this Section, for
action taken when Type C DTCs set and conditions for clearing Type C DTCs.
Additional Information
• Refer to 6C Fuel System – V6 for details of the fuel pump operation.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• 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.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.
DTC P0627 to P0629 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 Turn the ignition switch to the Start position or operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0627, P0628 and P0629 fail this ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 1 Remove the fuel pump relay. Refer to 8A Electrical - Body and
Chassis.
2 Connect a test lamp between the ground circuit of the fuel pump relay and a 12 V.
Does the test lamp illuminate? Go to Step 4 Go to Step 5
4 1 Connect a test lamp between the control circuit and ground
circuit of the fuel pump relay.
2 Using Tech 2, command the fuel pump relay on.
Does the test lamp switch from off to on as Tech 2 commands the fuel
pump relay from off to on? Go to Step 7 Go to Step 6

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Engine Management – V6 – Diagnostics Page 6C1-2–156

Step Action Yes
No
5 Repair the high resistance or open circuit fault condition in the ground
circuit of the fuel pump relay. Refer to 8A Electrical - Body and
Chassis for information on electrical wiring repair procedures.
W as the repair completed? Go to Step 9 —
6 Test the control circuit of the fuel pump relay for a high resistance,
open circuit, short to ground or a short to voltage fault condition. Refer
to 8A Electrical - Body and Chassis for information on electrical fault
diagnosis.
W as any fault found and rectified? Go to Step 9 Go to Step 8
7 Replace the fuel pump relay. Refer to 8A Electrical - Body and
Chassis.
W as the repair completed? Go to Step 9 —
8 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 9 —
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 the fuel pump relay control circuit 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.
7.38 DTC P0645, P0646 or P0647
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0645 – A/C Relay Circuit Malfunction.
• DTC P0646 – A/C Relay Voltage Low.
• DTC P0647 – A/C Relay Voltage High.
Circuit Description
The engine control relay applies battery voltage to the coil circuit of the air-conditioning (A/C) clutch relay through the
ignition circuit. Using a device called a driver, the ECM grounds control circuit of the A/C relay to activate the A/C clutch
and operate the A/C compressor. Refer to 2A Heater and Air-conditioning for details of the A/C compressor operation.
The driver has a feedback circuit that is pulled-up to a voltage. The ECM monitors the driver feedback circuit to
determine if the control circuit is open, shorted to ground or shorted to a positive voltage.
An A/C relay control circuit DTC sets if the ECM detects a fault condition in the A/C relay control circuit.
Conditions for Running the DTC
DTC P0645, P0646 or P0647 runs continuously once the following conditions are met:
• The ignition voltage is 10 – 16 V.
• The engine speed is greater than 80 rpm

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