2007 ISUZU KB P190 check engine

6E-74 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0087 (Flash Code 225)
Description
The common rail fuel system is comprised of two fuel
pressure sections: a suction side between the fuel tank
and the fuel supply pump and a high-pressure side
between the fuel supply pump and the fuel injectors.
Fuel is drawn from the fuel tank via a feed pump and
then pumped into the fuel rail by two plungers, all of
which are internal to the fuel supply pump. This high
pressure is regulated by the ECM using the fuel rail
pressure (FRP) regulator dependant upon values from
the FRP sensor attached to the fuel rail. In case of fuel
rail overpressure, a pressure limiter valve threaded into
the fuel rail will open to release overpressure and
return fuel back to the fuel tank. If the ECM detects that
the fuel rail pressure went excessively high, then
sharply decreased, this DTC will set indicating high fuel
pressure, which activated the pressure limiter valve.
Condition for Running the DTC • DTCs P0192 and P0193 are not set.
• The battery voltage is more than 9 volts.
• The ignition switch is ON.
• The engine is running.
Condition for Setting the DTC • The ECM detects that the pressure limiter valve is activated with overpressure (more than 190 MPa
[27,600 psi]) in the fuel rail.
Action Taken When the DTC Sets • The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A. • The ECM limits fuel injection quantity.
• The ECM inhibits pilot injection.
• The ECM inhibits cruise control.
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A.
Diagnostic Aids • An intermittently sticking FRP regulator may have allowed the fuel pressure to become high enough
to open the pressure limiter valve.
• A skewed FRP sensor value can set this DTC. The FRP Sensor on the scan tool 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.
Notice: • If the fuel tank is empty or near empty, air might be allowed to go into the fuel system. With air in the
fuel system, smooth flow of fuel into the supply
pump is interrupted and this DTC may set. Perform
bleeding of fuel system after refilling.
Schematic Reference: Fuel System Routing Diagram
and Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0087
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. Start the engine.
4. Monitor the DTC Information with a scan tool.
Is DTC P0088, P0089, P0091, P0092, P0192,
P0193, P0201 - P0204, P1064, P1065, P124B or
P2146 - P2151 set? —
Go to Applicable DTC Go to Step 3

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-75
31. Turn OFF the ignition.
2. Place the transmission in Neutral and set the parking brake.
3. Start the engine.
4. Accelerate the engine between idle and W.O.T. (accelerator pedal full travel) many
times while observing the DTC Information
with a scan tool.
Does the DTC fail this ignition? —
Go to Step 4 Go to Diagnostic
Aids
4 1. Turn OFF the ignition.
2. Wait 1 minute for the fuel pressure to bleed down from the fuel rail.
3. Turn ON the ignition, with the engine OFF. DO NOT start the engine.
4. Observe the Fuel Rail Pressure (FRP) Sensor parameter with the scan tool.
Does the scan tool indicate within the specified
value? 0.9 to 1.0 volt
Go to Step 5 Go to Step 10
5 1. Start the engine.
2. Perform the Cylinder Balance Test with a scan tool.
3. Command each injector OFF and verify an engine speed change for each injector.
Is there an injector that does not change engine
speed when commanded OFF? —
Go to Step 12 Go to Step 6
6 1. Check the fuel system line connections
between the fuel tank and the fuel supply
pump for tightness and all fuel hoses for cuts,
cracks and for the use of proper clamps.
Notice: Air in the fuel system will cause fuel rail
pressure fluctuations especially at high engine
speed and load, which may set this DTC.
2. Start the engine and check for high side fuel system leaks at the fuel supply pump and fuel
rail.
Notice: Fuel may leak under the cylinder head
cover from the inlet high pressure line. In such
case, the engine oil level will rise. Inspect for fuel
leakage into the engine oil.
3. Repair any fuel system leaks as necessary.
Did you find and correct the condition? —
Go to Step 14 Go to Step 7
Step
Action Value(s)Yes No

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ISUZU KB P190 2007

6E-76 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
7Notice:
Make sure the in-tank fuel pump operation
before performing the following procedures. Refer
to In-tank Fuel Pump System Check in this section.
1. Turn OFF the ignition.
2. Disconnect the fuel hose from the fuel supply pump suction side. In order to measure the
discharged fuel amount, put the hose into a
bottle or a container with a scale. (The inlet of
a bottle or a container must be larger than the
diameter of hose.)
3. Turn ON the ignition for 20 seconds, with the engine OFF.
4. Turn OFF the ignition for 10 seconds.
5. Perform 3 and 4 three times. The accumulated fuel of three ignition cycles must be more than
300 cc. (Normal amount is more than 100 cc
per one ignition cycle.)
Notice: If there is a leak or a restriction on the
suction side, the fuel from the hose will not flow out
sufficiently that is most likely caused by fuel
leakage, clogged fuel filter, kinked or crushed fuel
hose or pipe. Also inside the fuel tank for any
foreign materials may be getting drawn into the fuel
line pickup.
6. Repair fuel system leaking or restrictions as necessary.
Did you find and correct the condition? —
Go to Step 14 Go to Step 8
8 1. Remove the fuel hose that connects to the fuel
supply pump suction side and substitute a
clear hose.
Notice: The hose must be cleaned before
connecting to the fuel line. Otherwise, foreign
material internal to the hose may damage the fuel
supply pump.
2. Bleed the fuel system. Repeat as necessary until the engine starts.
3. Let the engine run at idle for at least 1 minute.
4. Observe the clear hose while holding the engine speed higher than 3000 RPM for a
minimum of 1 minute.
Notice: If many air bubbles appear in the fuel,
check the fuel line connections between the fuel
supply pump and the fuel tank for tightness and all
fuel hoses for cuts, cranks and for the uses of
proper clamps.
5. Repair or replace as necessary.
Did you find and correct the condition? —
Go to Step 14 Go to Step 9
Step
Action Value(s)Yes No

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-79
DTC P0088 (Flash Code 118)
Description
The common rail fuel system is comprised of two fuel
pressure sections: a suction side between the fuel tank
and the fuel supply pump and a high-pressure side
between the fuel supply pump and the fuel injectors.
Fuel is drawn from the fuel tank via a feed pump and
then pumped into the fuel rail by two plungers, all of
which are internal to the fuel supply pump. This high
pressure is regulated by the ECM using the fuel rail
pressure (FRP) regulator dependant upon values from
the FRP sensor attached to the fuel rail.
If the ECM detects that the fuel pressure went
excessively high for a certain length of time, this DTC
will set (First Stage). If the ECM detects that during the
same ignition cycle the fuel pressure rose even higher
than the amount to set DTC P0088 for a certain length
of time, the engine is stopped (Second Stage). If the
engine is stopped, the fuel pressure was too high and
the pressure limiter valve did not active or did not active
quick enough.
Condition for Running the DTC • DTCs P0192 and P0193 are not set.
• The battery voltage is more than 9 volts.
• The ignition switch is ON.
• The engine is running.
Condition for Setting the DTC
First Stage • The ECM detects that the fuel rail pressure is more than 197 MPa (28,600 psi) for longer than 5
seconds.
Second Stage
• The ECM detects that the fuel rail pressure is more than 200 MPa (29,000 psi) for longer than 5
seconds.
Action Taken When the DTC Sets
First Stage • The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.
• The ECM limits fuel injection quantity.
• The ECM inhibits pilot injection.
• The ECM inhibits cruise control.
Second Stage • The ECM illuminates the SVS lamp when the
diagnostic runs and fails. Refer to DTC Type
Definitions for Action Taken When the DTC Sets -
Type C. (Euro 4 Specification)
• The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.
(Except Euro 4 Specification)
• The ECM limits fuel injection quantity.
• The ECM inhibits pilot injection.
• The ECM inhibits cruise control.
• The ECM stops engine running when the vehicle speed is lower than 5 km/h (3 MPH) for 5 seconds.
The engine will run after the key is cycled when the
ignition has been tuned OFF for longer than 10
seconds.
Condition for Clearing the DTC
First Stage • Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A.
Second Stage
• Refer to DTC Type Definitions for Condition for Clearing the SVS Lamp/ DTC - Type C. (Euro 4
Specification)
• Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A. (Except Euro 4
Specification)
Diagnostic Aids • An intermittently sticking Fuel Rail Pressure regulator may have allowed the fuel pressure to
become high enough to set this DTC.
• Normal Fuel Rail Pressure readings on the scan tool with the engine running in neutral at idle is
around 27 to 33 MPa (3,900 to 48,00 psi) after
warm up.
• A skewed FRP sensor value can set this DTC. The FRP Sensor on the scan tool 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.
Schematic Reference: Fuel System Routing Diagram
and Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0088
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

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ISUZU KB P190 2007

6E-80 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
21. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the DTC Information with a scan tool.
Is DTC P0089, P0091, P0092, P0192, P0193,
P0201 - P0204, P0219, P1064, P1065, P124B or
P2146 - P2151 set? —
Go to Applicable DTC Go to Step 3
3 1. Turn OFF the ignition.
2. Place the transmission in Neutral and set the parking brake.
3. Start the engine.
4. Accelerate the engine between idle and W.O.T. (accelerator pedal full travel) many
times while observing the Fuel Rail Pressure
parameter with a scan tool.
Does the Fuel Rail Pressure parameter ever
exceed the specified value? 190 MPa
(27,600 psi)
Go to Step 4 Go to Step 11
4 1. Turn OFF the ignition.
2. Wait 1 minute for the fuel pressure to bleed down from the fuel rail.
3. Turn ON the ignition, with the engine OFF. DO NOT start the engine.
4. Observe the Fuel Rail Pressure (FRP) Sensor parameter with the scan tool.
Does the scan tool indicate within the specified
value? 0.9 to 1.0 volt
Go to Step 5 Go to Step 10
5 1. Start the engine.
2. Perform the Cylinder Balance Test with a scan tool.
3. Command each injector OFF and verify an engine speed change for each injector.
Is there an injector that does not change engine
speed when commanded OFF? —
Go to Step 13 Go to Step 6
6 1. Check the fuel system line connections
between the fuel tank and the fuel supply
pump for tightness and all fuel hoses for cuts,
cracks and for the use of proper clamps.
Notice: Air in the fuel system will cause fuel rail
pressure fluctuations especially at high engine
speed and load, which may set this DTC.
2. Start the engine and check for high side fuel system leaks at the fuel supply pump and fuel
rail.
Notice: Fuel may leak under the cylinder head
cover from the inlet high pressure line. In such
case, the engine oil level will rise. Inspect for fuel
leakage into the engine oil.
3. Repair any fuel system leaks as necessary.
Did you find and correct the condition? —
Go to Step 15 Go to Step 7
Step
Action Value(s)Yes No

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-81
7Notice:
Make sure the in-tank fuel pump operation
before performing the following procedures. Refer
to In-tank Fuel Pump System Check in this section.
1. Turn OFF the ignition.
2. Disconnect the fuel hose from the fuel supply pump suction side. In order to measure the
discharged fuel amount, put the hose into a
bottle or a container with a scale. (The inlet of
a bottle or a container must be larger than the
diameter of hose.)
3. Turn ON the ignition for 20 seconds, with the engine OFF.
4. Turn OFF the ignition for 10 seconds.
5. Perform 3 and 4 three times. The accumulated fuel of three ignition cycles must be more than
300 cc. (Normal amount is more than 100 cc
per one ignition cycle.)
Notice: If there is a leak or a restriction on the
suction side, the fuel from the hose will not flow out
sufficiently that is most likely caused by fuel
leakage, clogged fuel filter, kinked or crushed fuel
hose or pipe. Also inside the fuel tank for any
foreign materials may be getting drawn into the fuel
line pickup.
6. Repair fuel system leaking or restrictions as necessary.
Did you find and correct the condition? —
Go to Step 15 Go to Step 8
8 1. Remove the fuel hose that connects to the fuel
supply pump suction side and substitute a
clear hose.
Notice: The hose must be cleaned before
connecting to the fuel line. Otherwise, foreign
material internal to the hose may damage the fuel
supply pump.
2. Bleed the fuel system. Repeat as necessary until the engine starts.
3. Let the engine run at idle for at least 1 minute.
4. Observe the clear hose while holding the engine speed higher than 3000 RPM for a
minimum of 1 minute.
Notice: If many air bubbles appear in the fuel,
check the fuel line connections between the fuel
supply pump and the fuel tank for tightness and all
fuel hoses for cuts, cranks and for the uses of
proper clamps.
5. Repair or replace as necessary.
Did you find and correct the condition? —
Go to Step 15 Go to Step 9
Step
Action Value(s)Yes No

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ISUZU KB P190 2007

6E-84 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0089 (Flash Code 151)
Description
The common rail fuel system is comprised of two fuel
pressure sections: a suction side between the fuel tank
and the fuel supply pump and a high-pressure side
between the fuel supply pump and the fuel injectors.
Fuel is drawn from the fuel tank via a feed pump and
then pumped into the fuel rail by two plungers, all of
which are internal to the fuel supply pump. This high
pressure is regulated by the ECM using the fuel rail
pressure (FRP) regulator dependant upon values from
the FRP sensor attached to the fuel rail. If the ECM
detects that fuel pressure is a certain pressure higher
than the desired pressure, this DTC will set.
Condition for Running the DTC • DTCs P0091, P0092, P0192, P0193, P0652, P0653, P0201 - P0204, P1064, P1065, P124B and
P2146 - P2151 are not set.
• The battery voltage is more than 9 volts.
• The ignition switch is ON.
• The engine is running.
Condition for Setting the DTC • The ECM detects that the actual fuel rail pressure is more than 20 to 40 MPa (2,900 to 5,800 psi)
over the desired pressure for longer than 20
seconds. Action Taken When the DTC Sets
• The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.
• The ECM limits fuel injection quantity.
• The ECM inhibits pilot injection.
• The ECM inhibits cruise control.
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A.
Diagnostic Aids • An intermittently sticking FRP regulator may have allowed the fuel pressure to become high enough
to set this DTC.
• Normal Fuel Rail Pressure readings on the scan tool with the engine running in neutral at idle is
around 27 to 33 MPa (3,900 to 4,800 psi) after
warm up.
• A skewed FRP sensor value can set this DTC. The FRP Sensor on the scan tool 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.
Schematic Reference: Fuel System Routing Diagram
and Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0089
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. Start the engine.
4. Monitor the DTC Information with a scan tool.
Is DTC P0091, P0092, P0192, P0193, P0201 -
P0204, P0219, P1064, P1065, P124B or P2146 -
P2151 set? —
Go to Applicable DTC Go to Step 3
3 1. Turn OFF the ignition.
2. Wait 1 minute for the fuel pressure to bleed down from the fuel rail.
3. Turn ON the ignition, with the engine OFF. DO NOT start the engine.
4. Observe the Fuel Rail Pressure (FRP) Sensor parameter with the scan tool.
Does the scan tool indicate within the specified
value? 0.9 to 1.0 volt
Go to Step 4 Go to Step 5

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-87
DTC P0091 or P0092 (Flash Code 247)
Circuit Description
The fuel rail pressure (FRP) regulator is installed to the
fuel supply pump and controls the suction fuel quantity
into the fuel rail. The FRP regulator is fully opened in
the normal state and larger drive current results in
smaller opening. The ECM calculates desired fuel rail
pressure and fuel flow rate and it compares the
calculated desired fuel rail pressure to the actual value
to determine the FRP regulator position. When the
actual fuel rail pressure is higher than the desired
value, the FRP regulator is closed to decease the flow
rate. If the ECM detects an excessively low or high FRP
regulator feedback current, DTC P0091 or P0092 will
set.
Condition for Running the DTC • The battery voltage is more than 9 volts.
• The ignition switch is ON.
Condition for Setting the DTC • The ECM detects that the FRP regulator feedback current is less than 100mA, or more than 1000mA
below the desired current. (DTC P0091)
• The ECM detects that the FRP regulator feedback current is more than 2450mA, or more than
1000mA over the desired current. (DTC P0092) Action Taken When the DTC Sets
• The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.
• The ECM limits fuel injection quantity.
• The ECM inhibits pilot injection.
• The ECM inhibits cruise control.
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A.
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
Test Description
The number below refers to the step number on the
Circuit/ System Testing.
8. If the FRP regulator high side circuit is shorted to
voltage, engine stalls and will not start.
9. If the FRP regulator low side circuit is shorted to
ground, this DTC may not set. This will cause engine
stall or no engine start.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0091 or P0092
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.
Does the DTC fail this ignition? —
Go to Step 3 Go to Diagnostic
Aids
3 Is DTC P1064 also set? — Go to DTC P1064 Go to Step 4
4 Observe the Fuel Rail Pressure (FRP) Regulator
Feedback parameter with a scan tool.
Does the scan tool indicate more than the specified
value? 300 mA
Go to Step 5 Go to Step 6
5 Does the scan tool indicate more than the specified
value at Step 4? 1300 mA
Go to Step 8 Go to Step 9

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ISUZU KB P190 2007