2007 ISUZU KB P190 ignition

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-319
71. Remove the Meter (10A) fuse that supplies
voltage to the IP cluster.
2. Turn ON the ignition, with the engine OFF.
3. Measure the voltage from the cruise set lamp control circuit in the ECM harness connector
(pin 49 of C-58) to a good ground.
Is the voltage less than the specified value? 1 volt
Go to Step 8 Go to Step 10
8 1. Turn OFF the ignition.
2. Reinstall the Meter (10A) fuse.
3. Turn ON the ignition, with the engine OFF.
4. Connect a 3-amp fused jumper wire between the cruise set lamp control circuit of the ECM
harness connector (pin 49 of C-58) and a
known good ground.
Is the cruise main lamp illuminated? —
Go to Step 12 Go to Step 9
9 1. Test the control circuit between the ECM (pin
49 of C-58) and the IP cluster (pin 23 of B-23)
for an open circuit or high resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 15 Go to Step 11
10 Repair the short to battery or ignition voltage on the
control circuit between the ECM (pin 49 of C-58)
and the IP cluster (pin 23 of B-23).
Did you complete the action? —
Go to Step 15
—
111. Inspect for an intermittent and for a poor
connection at the harness connector of the IP
cluster (pins 23 of B-23).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 15 Go to Step 13
12 1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for poor connections on the cruise main or set lamp
control circuit at the harness connector of the
ECM (pin 49 or 50 of C-58).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 15 Go to Step 14
13 Repair or replace the IP cluster.
Did you complete the repair or replacement? —
Go to Step 15
—
14Important
: Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 15
—
15Reconnect all previously disconnected
components, fuse or harness connector(s).
Is the action complete? —
Go to 1 of 2 Step 2
—
Step Action Value(s)Yes No

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ISUZU KB P190 2007

6E-320 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Turbocharger Control System Check
Description
The position of the turbocharger nozzle is controlled by
the ECM. The ECM utilizes a turbocharger nozzle
control solenoid valve and a boost pressure sensor to
control the turbocharger nozzles. When the engine is
not under load, the turbocharger nozzles are in an open
position, or no boost condition. When the engine is
under load, the ECM commands the control solenoid
valve to close the turbocharger nozzles, thus
increasing the boost. The ECM will vary the boost
dependant upon the load requirements of the engine.
The ECM uses a pulse width modulation (PWM) on the
control circuit to open and control the solenoid valve. Notice:
• This Circuit/ System Testing is only applicable to high output engine.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing Turbocharger Control System Check
Step Action Value(s)Yes No
1 Did you perform the Diagnostic System Check -
Engine Controls? —
Go to Step 2 Go to Diagnostic
System Check -
Engine Controls
2 1. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Turn ON the ignition, with the engine OFF.
4. Monitor the DTC Information with a scan tool.
Is DTC P0045, P0107, P0108, P0112, P0113,
P0116, P0117, P0118, P0234, P0299, P0638,
P0698, P0699, P1196, P1197, P1198, P2227,
P2228 or P2229 also set? —
Go to Applicable DTC Go to Step 3

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ISUZU KB P190 2007

6E-322 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
51. Turn OFF the ignition.
2. Disconnect the vacuum hose from the turbocharger nozzle control actuator
diaphragm.
3. Connect a hand-held vacuum pump (5-8840- 0279-0/ J-23738-A) to the disconnected
vacuum hose.
4. Start the engine and let idle.
5. Perform the Turbocharger Solenoid Control with a scan tool.
6. Command the solenoid valve Increase and Decrease while observing the vacuum pump.
Does the hand-held vacuum pump reading more
than 50 cmHg (20 inHg) when commanded
maximum Increase and ZERO range when
commanded minimum Decrease? —
Go to Step 8 Go to Step 6
6 1. Inspect the following conditions:
• Misrouted, disconnected, kinked orplugged turbocharger nozzle actuator
control vacuum hose.
• Misrouted, disconnected, kinked or plugged solenoid valve ventilation hose.
• Misrouted, disconnected, kinked or plugged vacuum source hose or pipe.
2. Repair or replace as necessary.
Did you find and correct the condition? —
Go to Step 8 Go to Step 7
7 Replace the turbocharger nozzle control solenoid
valve.
Did you complete the replacement? —
Go to Step 8
—
81. Reconnect all previously disconnected
components or harness connector(s).
2. Clear the DTCs with a scan tool if set.
3. Turn OFF the ignition for 30 seconds.
Did you complete the action? —
Go to Step 2
—
Step Action Value(s)Yes No

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ISUZU KB P190 2007

6E-328 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Hard Start
ChecksAction
Definition:
The engine cranks OK, but does not start for a long time. The engine does eventually run, or may start but immediately dies.
Preliminary Checks • Diagnostic System Check - Engine Controls.
• Ensure the driver is using the correct starting procedure.
• Inspect the ECM grounds for being clean, tight, and in their proper locations.
• Inspect that the harness connectors are correctly connected.
• Inspect the fuel type and quality.
• Inspect the programmed fuel injector ID code for each cylinder.
• Inspect the Scan Tool Data List in this section.
• Inspect the Service Bulletin.
Sensor Checks Inspect the engine control sensors for the following conditions. Refer to the Scan Tool
Data List in this section.
• Compare the Coolant Temperature with the Intake Air Temperature (IAT) and Fuel Temperature (FT) parameters on a cold engine condition. If the difference among
temperature reading is more than 5 °C (9 °F) on a cold engine, check for high
resistance in each circuit or for a skewed sensor.
Notice: The mass air flow (MAF) sensor is heated and as a result the IAT may indicate
a higher than normal intake air temperature if the ignition switch is being ON.
• Observe the Fuel Rail Pressure (FRP) Sensor parameter with the engine OFF. The FRP Sensor should read 0.9 to 1.0 volt with the key ON and engine OFF after the
engine has stopped running for a minimum of 1 minute. If not, check for high
resistance in each circuit or for a skewed sensor.
• Crankshaft position (CKP) sensor is tight and the sensor rotor is not damaged.
• Camshaft position (CMP) sensor is tight and the timing chain sprocket is not damaged.
Fuel System Checks Inspect the fuel system for the following conditions. Refer to Fuel System Check chart
and appropriate procedure in the Fuel System section.
• Air in the fuel system.
• Water contamination in the fuel.
• Fuel waxing or icing.
• Fuel filter indicator lamp is continuously or frequently turned ON with engine run.
• External fuel leaks or high engine oil level.
• In-tank fuel pump operation. Refer to In-tank Fuel Pump System Check in this section.
• Fuel leak off from the fuel pressure limiter valve and fuel injectors.
• Fuel lines between the fuel tank and fuel supply pump for being crushed, kinked, tightness, cracks and plugged.
• A plugged fuel tank vent valve and hose.
• Inside the fuel tank for any foreign material that may be getting drawn into the fuel line pickup causing a blocked condition.
• Fuel supply pump operation.
Notice: The fuel supply pump must be timed to the engine and adjustment value must
be learned to the ECM.
• Perform the Cylinder Balance Test with a scan tool.
• Perform the Injector Force Drive with a scan tool.
• Observe the FRP Regulator Feedback current on the scan tool.

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ISUZU KB P190 2007

6E-330 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Rough, Unstable, or Incorrect Idle and Stalling
ChecksAction
Definition:
Engine runs unevenly at idle. If severe, the engine or vehicle may shake. Engine idle speed may vary in RPM. Either condition
may be severe enough to stall the engine.
Preliminary Checks • Diagnostic System Check - Engine Controls.
• Remove the air cleaner and check for dirt, or for air ducts being plugged or restricted. Replace as necessary.
• Inspect the ECM grounds for being clean, tight, and in their proper locations.
• Inspect that the harness connectors are correctly connected.
• Inspect the fuel type and quality.
• Inspect the programmed fuel injector ID code for each cylinder.
• Inspect the Scan Tool Data List in this section.
• Inspect the Service Bulletin.
Sensor Checks Inspect the engine control sensors for the following conditions. Refer to the Scan Tool
Data List in this section.
• Compare the Coolant Temperature with the Intake Air Temperature (IAT) and Fuel Temperature (FT) parameters on a cold engine condition. If the difference among
temperature reading is more than 5 °C (9 °F) on a cold engine, check for high
resistance in each circuit or for a skewed sensor.
Notice: The mass air flow (MAF) sensor is heated and as a result the IAT may indicate
a higher than normal intake air temperature if the ignition switch is being ON.
• Observe the Fuel Rail Pressure (FRP) Sensor parameter with the engine OFF. The FRP Sensor should read 0.9 to 1.0 volt with the key ON and engine OFF after the
engine has stopped running for a minimum of 1 minute. If not, check for high
resistance in each circuit or for a skewed sensor.
• Observe the Fuel Rail Pressure parameter at idle in Neutral. The Fuel Rail Pressure should always be within 27 to 33 MPa (3,900 to 4,800 psi) after warm up.
• Crankshaft position (CKP) sensor is tight and the sensor rotor is not damaged.
• Camshaft position (CMP) sensor is tight and the timing chain sprocket is not damaged.
Fuel System Checks Inspect the fuel system for the following conditions. Refer to Fuel System Check Chart
and appropriate procedure in the Fuel System section.
• Air in the fuel system.
• Water contamination in the fuel.
• Fuel waxing or icing.
• Fuel filter indicator lamp is continuously or frequently turned ON with engine run.
• External fuel leaks or high engine oil level.
• In-tank fuel pump operation. Refer to In-tank Fuel Pump System Check in this section.
• Fuel leak off from the fuel pressure limiter valve and fuel injectors.
• Fuel lines between the fuel tank and fuel supply pump for being crushed, kinked, tightness, cracks and plugged.
• A plugged fuel tank vent valve and hose.
• Inside the fuel tank for any foreign material that may be getting drawn into the fuel line pickup causing a blocked condition.
• Fuel supply pump operation.
Notice: The fuel supply pump must be timed to the engine and adjustment value must
be learned to the ECM.
• Perform the Cylinder Balance Test with a scan tool.
• Perform the Injector Force Drive with a scan tool.
• Observe the Fuel Compensation for each cylinder at idle on the scan tool.
• Observe the FRP Regulator Feedback current on the scan tool.

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ISUZU KB P190 2007

6E-332 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
High Idle Speed
ChecksAction
Definition:
Engine idle speed is higher than normal in regardless of engine coolant temperature.
Preliminary Checks • Diagnostic System Check - Engine Controls.
• Inspect that the harness connectors are correctly connected.
• Use the scan tool to compare the engine speed and tachometer on the instrument panel (IP) cluster.
• Inspect the battery voltage. If the battery voltage is less than 11 volts, the ECM set the idle speed 50RPM higher than normal.
• Inspect the A/C operation.
• Inspect the fuel type and quality.
• Inspect the engine oil level.
• Inspect the Scan Tool Data List in this section.
• Inspect the Service Bulletin.
Sensor Checks Inspect the engine control sensors for the following conditions. Refer to the Scan Tool
Data List in this section.
• Compare the Coolant Temperature with the Intake Air Temperature (IAT) and Fuel Temperature (FT) parameters on a cold engine condition. If the difference among
temperature reading is more than 5 °C (9 °F) on a cold engine, check for high
resistance in each circuit or for a skewed sensor.
Notice: The mass air flow (MAF) sensor is heated and as a result the IAT may indicate
a higher than normal intake air temperature if the ignition switch is being ON.
• Observe the Fuel Rail Pressure (FRP) Sensor parameter with the engine OFF. The FRP Sensor should read 0.9 to 1.0 volt with the key ON and engine OFF after the
engine has stopped running for a minimum of 1 minute. If not, check for high
resistance in each circuit or for a skewed sensor.
• Observe the Fuel Rail Pressure parameter at idle in Neutral. The Fuel Rail Pressure should always be within 27 to 33 MPa (3,900 to 4,800 psi) after warm up.
• Observe the Accelerator Pedal Position (APP). APP parameter should change linearly from 0 to 100% according to the accelerator pedal operation.
Fuel System Checks Inspect the fuel system for the following conditions. Refer to the Fuel System section.
• Fuel injectors. Remove the injectors and visually inspect. (Injector tip(s) may be damaged)

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ISUZU KB P190 2007

6E-336 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Lack of Power, Sluggishness or Sponginess
ChecksAction
Definition:
The engine delivers less than expected power. There is little or no increase in speed when partially applying the accelerator
pedal.
Preliminary Checks • Diagnostic System Check - Engine Controls.
• Compare the vehicle with a similar unit. Ensure the vehicle has an actual problem.
• Remove the air cleaner and check for dirt, or for air ducts being plugged or restricted. Replace as necessary.
• Have the tire sizes changed?
• Are excessively heavy loads being carried?
• Inspect for clutch slip.
• Inspect brake drag.
• Inspect for a proper transmission shift pattern and down shift operation.
• Inspect the fuel quality (cetane index).
• Inspect the engine oil level and quality.
• Use the scan tool in order to make sure the Vehicle Speed parameter reading matches the vehicle speedometer.
• Inspect the ECM grounds for being clean, tight, and in their proper locations.
• Inspect the programmed fuel injector ID code for each cylinder.
• Inspect the Scan Tool Data List in this section.
• Inspect the Service Bulletin.
Sensor Checks Inspect the engine control sensors for the following conditions. Refer to the Scan Tool
Data List in this section.
• Compare the Coolant Temperature with the Intake Air Temperature (IAT) and Fuel Temperature (FT) parameters on a cold engine condition. If the difference among
temperature reading is more than 5 °C (9 °F) on a cold engine, check for high
resistance in each circuit or for a skewed sensor.
Notice: The mass air flow (MAF) sensor is heated and as a result the IAT may indicate
a higher than normal intake air temperature if the ignition switch is being ON.
• Observe the MAF parameter for a skewed or slow MAF sensor.
• Observe the Fuel Rail Pressure (FRP) Sensor parameter with the engine OFF. The FRP Sensor should read 0.9 to 1.0 volt with the key ON and engine OFF after the
engine has stopped running for a minimum of 1 minute. If not, check for high
resistance in each circuit or for a skewed sensor.
• Observe the Fuel Rail Pressure and Desired Fuel Rail Pressure parameter between idle and W.O.T. (accelerator pedal full travel) in Neutral. Fuel Rail Pressure
parameter should follow within ± 5 MPa ( ± 725 psi) quick enough.
• Observe the Accelerator Pedal Position (APP). APP parameter should change linearly from 0 to 100% according to the accelerator pedal operation.
• Observe the Barometric Pressure (BARO) parameter. The BARO parameter should indicate near surrounding barometric pressure. Refer to Altitude vs. Barometric
Pressure. (Standard output)
• Observe the Boost Pressure and BARO with ignition ON and engine OFF. Both parameters should be within the 7.0 kPa (1.0 psi) each other. (High output)

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ISUZU KB P190 2007

6E-338 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Hesitation, Sag or Stumble
ChecksAction
Definition:
The vehicle has a momentary lack of response when pushing down on the accelerator. The condition can occur at any vehicle
speed. The condition is usually most severe when trying to make the vehicle move from a stop. If severe enough, the condition
may cause the engine to stall.
Preliminary Checks • Diagnostic System Check - Engine Controls.
• Compare the vehicle with a similar unit. Ensure the vehicle has an actual problem.
• Remove the air cleaner and check for dirt, or for air ducts being plugged or restricted. Replace as necessary.
• Inspect for a proper transmission shift pattern and down shift operation.
• Inspect the fuel quality (cetane index).
• Inspect the engine oil level and quality.
• Inspect the ECM grounds for being clean, tight, and in their proper locations.
• Inspect the programmed fuel injector ID code for each cylinder.
• Inspect the Scan Tool Data List in this section.
• Inspect the Service Bulletin.
Sensor Checks Inspect the engine control sensors for the following conditions. Refer to the Scan Tool
Data List in this section.
• Compare the Coolant Temperature with the Intake Air Temperature (IAT) and Fuel Temperature (FT) parameters on a cold engine condition. If the difference among
temperature reading is more than 5 °C (9 °F) on a cold engine, check for high
resistance in each circuit or for a skewed sensor.
Notice: The mass air flow (MAF) sensor is heated and as a result the IAT may indicate
a higher than normal intake air temperature if the ignition switch is being ON.
• Observe the MAF parameter for a skewed or slow MAF sensor.
• Observe the Fuel Rail Pressure (FRP) Sensor parameter with the engine OFF. The FRP Sensor should read 0.9 to 1.0 volt with the key ON and engine OFF after the
engine has stopped running for a minimum of 1 minute. If not, check for high
resistance in each circuit or for a skewed sensor.
• Observe the Fuel Rail Pressure and Desired Fuel Rail Pressure parameter between idle and W.O.T. (accelerator pedal full travel) in Neutral. Fuel Rail Pressure
parameter should follow within ± 5 MPa ( ± 725 psi) quick enough.
• Observe the Accelerator Pedal Position (APP). APP parameter should change linearly from 0 to 100% according to the accelerator pedal operation.
• Observe the Barometric Pressure (BARO) parameter. The BARO parameter should indicate near surrounding barometric pressure. Refer to Altitude vs. Barometric
Pressure. (Standard output)
• Observe the Boost Pressure and BARO with ignition ON and engine OFF. Both parameters should be within the 7.0 kPa (1.0 psi) each other. (High output)
• Crankshaft position (CKP) sensor is tight and the sensor rotor is not damaged.

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ISUZU KB P190 2007