display ISUZU KB P190 2007 Workshop Repair Manual

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 6C1-2–146

Step Action Yes No
3 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0532 or P0533 fail this ignition cycle? Go to Step 4 Refer to Additional
Information in this DTC
4 1 Switch off the ignition.
2 Disconnect the A/C pressure sensor connector.
3 Switch on the ignition with the engine not running.
4 Using a digital multimeter, measure the voltage between the A/C pressure sensor 5 V reference circuit and the ECM housing.
Does the multimeter display 4.8 – 5.2 V? Go to Step 5 Go to Step 7
5 1 Connect a 3 A fused jumper wire between the A/C pressure
sensor 5 V reference circuit and signal circuit.
2 Switch on the ignition with the engine not running.
3 Using Tech 2, observe the ECM A/C pressure voltage parameter.
Does Tech 2 display 4.8 – 5.2 V?
Go to Step 6 Go to Step 8
6 1 Switch off the ignition.
2 Remove ECM Fuse 29 from the engine compartment fuse and relay panel assembly.
3 Using a digital multimeter, measure the resistance between the A/C refrigerant pressure low reference circuit and the ECM
housing.
NOTE
Install the ECM Fuse 29 to the engine compartment fuse
and relay panel assembly after completing the test.
Does the multimeter display 5 Ω? Go to Step 10 Go to Step 9
7 Test the A/C pressure sensor 5 V reference 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 12 Go to Step 11
8 Test the A/C pressure sensor signal 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 12 Go to Step 11
9 Test the A/C pressure sensor low reference circuit for a high
resistance or open circuit condition. Refer to 8A Electrical - Body and
Chassis for information on electrical fault diagnosis.
W as any fault found and rectified? Go to Step 12 Go to Step 11
10 Replace the A/C pressure sensor. Refer to 6C1-3 Engine
Management – V6 – Service Operations.
W as the repair completed? Go to Step 12 —
11 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 12 —

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Engine Management – V6 – Diagnostics Page 6C1-2–147

Step Action Yes No
12 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 A/C refrigerant pressure sensor circuit DTCs fail this
ignition cycle? Go to Step 2 Go to Step 13
13 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.
7.33 DTC P0560, P0562 or P0563
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0560 – System Voltage Malfunction
• DTC P0562 – System Voltage Low Voltage
• DTC P0563 – System Voltage High Voltage
Circuit Description
Battery voltage is supplied continuously to the engine control module (ECM) through the continuous battery supply
circuit and the ground through the ground connection of the ECM housing to the engine.
Turning the ignition switch on activates the ignition control relay, which directs ignition positive voltage from the battery
to the ECM switched battery supply circuit which activates the ECM. The ECM then applies control voltage to the control
circuit of the engine control relay to activate the engine control relay. The engine control relay supplies ignition voltage
to the various engine management system components.
The ECM monitors the battery voltage circuits to ensure the voltage available to the engine management system stays
within the specified range. Incorrect system voltage may cause incorrect engine management system operation or
component malfunction.
An ECM system voltage DTC sets if the ECM detects the voltage available to any of the ECM voltage supply circuit is
outside the specified range.
Conditions for Running the DTC
DTCs P0560, P0563 and P0563 runs continuously when the engine is running at speeds greater than 1500 rpm
Conditions for Setting the DTC
DTC P0560
The ECM detects the ignition 1, ignition 2 or switched battery supply voltage is out of the specified range for 30 seconds.
DTC P0562
The ECM detects the ECM system voltage is less than 11 V for 5 seconds.
DTC P0563
The ECM detects the ECM system voltage is greater than 16 V.

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Engine Management – V6 – Diagnostics Page 6C1-2–148

Conditions for Clearing the DTC
The ECM system voltage DTCs are Type C DTCs. 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
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• Refer to 6C1-1 Engine Management – V6 – General Information for details of the ECM operation.
• 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 P0560, P0562 or P0563 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 Increase the engine speed to 1500 rpm or operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0560, P0562, or P0563 fail this ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 Test the battery condition. Refer to 6D1-3 Battery – V6.
W as any fault found and rectified? Go to Step 9 Go to Step 4
4 Test the charging system operation. Refer to 6D1-1 Charging System
– V6.
W as any fault found and rectified? Go to Step 9 Go to Step 5
5 Test all the ECM fuses. Refer to 8A Electrical - Body and Chassis.
W as any fault found and rectified? Go to Step 9 Go to Step 6
6 Check the ECM ground connections for corrosion, loose terminal or
incorrect position. 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 7
7 Test the following circuits for a high resistance or open circuit fault
condition.
• Continuous battery supply circuit,
• switched battery supply circuit,
• ignition 1 circuit, and
• ignition 2 circuit.
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
8 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 9 —

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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 6C1-2–150

DTC P0606
There is an internal ECM circuit fault condition for 6 seconds.
Conditions for Clearing the DTC
The ECM Internal Circuit, Programming or Memory Fault DTCs are Type A DTCs. Refer to 1.4 Diagnostic Trouble
Codes in this Section, for action taken when a Type A DTC sets and conditions for clearing Type A DTCs.
Additional Information
• Refer to 6C1-1 Engine Management – V6 – General Information for details of the ECM operation.
• 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.
DTC P0601, P0602, P0604 and P0606 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 Operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0601, P0602, P0604 or P0606 fail this ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 Test all ECM fuses and ground connections. Refer to 8A Electrical -
Body and Chassis.
W as any fault found and rectified? Go to Step 6 Go to Step 4
4 Attempt to program the ECM.
W as the programming successful? Go to Step 6 Go to Step 5
5 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 6 —
6 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 internal circuit, programming or memory fault
DTCs 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, check the system for correct operation.

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Engine Management – V6 – Diagnostics Page 6C1-2–152

Step Action Yes No
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 P0615, P0616 and P0617 fail this ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 Check for a fault condition in the following systems which can disable
the starting system:
• Starting System, refer to 6D1-2 Starting System – V6.
• Immobiliser System, refer to 11A Immobiliser.
W as any fault found and rectified? Go to Step 10 Go to Step 4
4 1 Remove the starter relay. Refer to 8A Electrical - Body and
Chassis.
2 Connect a test lamp between the ignition circuit of the starter relay and a good ground.
3 Switch on the ignition.
Does the test lamp illuminate when the ignition switch is turned to the
on position? Go to Step 5 Go to Step 6
5 1 Connect a test lamp between the control circuit of the starter
relay and a 12 V.
2 Turn the ignition switch to the Start position and then release it back to the on position.
Does the test lamp turn on when the ignition switch is turned to the
Start position and then turn off when the ignition switch returns to the
on position? Go to Step 8 Go to Step 7
6 Repair the ignition voltage circuit of the starter relay for a high
resistance or open circuit fault condition. Refer to 8A Electrical - Body
and Chassis for information on electrical wiring repair procedures.
W as the repair completed? Go to Step 10
—
7 Test the control circuit of the starter 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 10 Go to Step 9
8 Replace the starter relay. Refer to 8A Electrical - Body and Chassis.
W as the repair completed? Go to Step 10
—
9 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 10
—
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 the starter relay control circuit DTCs 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

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Engine Management – V6 – Diagnostics Page 6C1-2–154

• Refer to 6D1-1 Charging System – V6 for details of the charging system operation.
• 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 P0625 or P0626 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 Operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0625 or P0626 fail this ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 Test the charging system for any fault condition that may cause
incorrect generator operation. Refer to 6D1-1 Charging System – V6.
W as any fault found and rectified? Go to Step 6 Go to Step 4
4 Test the Gen F signal 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 6 Go to Step 5
5 Replace the ECM. Refer to Refer to 6C1-3 Engine Management – V6
– Service Operations.
W as the repair completed? Go to Step 7 —
6 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 Generator F-terminal circuit DTCs fail this ignition
cycle? Go to Step 2 Go to Step 8
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.
7.37 DTC P0627, P0628 or P0629
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0627 – Fuel Pump Relay Circuit Malfunction
• DTC P0628 – Fuel Pump Relay Voltage Low
• DTC P0629 – Fuel Pump Relay Voltage High

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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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