ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-67
61. Remove the rubber hoses from the leak-off
pipes that are connected to each fuel injector.
2. Crank over the engine while observing the fuel leak from the leak-off pipe of each fuel injector
(very small leak is normal).
Important: Safety glasses must be worm. Fuel
may splash if the fuel injector is faulty.
Important: Replacement fuel injector must be
programmed.
3. Replace the fuel injector(s) that return fuel is excessive. Refer to Fuel Injector
Replacement/ Fuel Injector ID Code Data
Programming.
4. Retest after replacement of the fuel injector(s).
Did you find and correct the condition? —
Go to Step 12 Go to Step 7
7 1. Remove each glow plug from the cylinder
head.
2. Inspect for fuel leakage into the combustion chamber.
Is there a cylinder that fuel leakage into the
combustion chamber? —
Go to Step 9 Go to Step 10
8 Important
: Replacement fuel injector must be
programmed.
Replace the appropriate fuel injector that does not
create a clicking noise (solenoid operating noise),
contains an interrupted noise or abnormal noise at
Step 1. Refer to Fuel Injector Replacement/ Fuel
Injector ID Code Data Programming.
Did you complete the replacement? —
Go to Step 12
—
9Important
: Replacement fuel injector must be
programmed.
Replace the appropriate fuel injector that was
leaking fuel found at Step 7 and inspect the engine
mechanical for any damage or poor engine
compression. Refer to Fuel Injector Replacement/
Fuel Injector ID Code Data Programming and
engine mechanical section.
Did you complete the replacement? —
Go to Step 12
—
10Important
: The fuel supply pump must be timed to
the engine and adjustment value must be learned
to the ECM.
Notice: Always replace the fuel filter cartridge
when a fuel supply pump is replaced.
Replace the fuel supply pump and fuel filter
cartridge. Refer to Fuel Supply Pump Replacement
and Fuel Filter Cartridge Replacement.
Did you complete the replacement? —
Go to Step 12
—
11Replace the pressure limiter valve. Refer to Fuel
Rail Replacement.
Did you complete the replacement? —
Go to Step 12
—
Step Action Value(s)Yes No
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TO MODEL INDEX
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-77
91. Turn OFF the ignition.
2. Disconnect the FRP regulator harness connector.
3. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the FRP regulator (pins 1 and 2
of E-50).
4. Disconnect the ECM harness connector.
5. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the ECM (pins 34, 50, 54 and 70
of E-90).
6. Test for high resistance on each circuit.
7. Repair the connection(s) or circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 14 Go to Step 13
10 1. Turn OFF the ignition.
2. Disconnect the FRP sensor harness connector.
3. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the FRP sensor (pins 1, 2 and 3
of E-48).
4. Disconnect the ECM harness connector.
5. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the ECM (pins 47, 48, 68 and 69
of E-90).
6. Test for high resistance on each circuit.
7. Repair the connection(s) or circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 14 Go to Step 11
11 Replace the FRP sensor. Refer to FRP sensor
Replacement.
Did you complete the replacement? —
Go to Step 14
—
12Important:
Replacement fuel injector must be
programmed.
Replace the appropriate fuel injector that does not
change engine speed when commanded OFF.
Refer to Fuel Injector Replacement/ Fuel Injector
ID Code Data Programming.
Did you complete the replacement? —
Go to Step 14
—
13Important:
The fuel supply pump must be timed to
the engine and adjustment value must be learned
to the ECM.
Notice: Always replace the fuel filter cartridge
when a fuel supply pump is replaced.
Replace the fuel supply pump and fuel filter
cartridge. Refer to Fuel Supply Pump Replacement
and Fuel Filter Cartridge Replacement.
Did you complete the replacement? —
Go to Step 14
—
Step Action Value(s)Yes No
BACK TO CHAPTER INDEX
TO MODEL INDEX
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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TO MODEL INDEX
ISUZU KB P190 2007
6E-82 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
91. Turn OFF the ignition.
2. Disconnect the FRP regulator harness connector.
3. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the FRP regulator (pins 1 and 2
of E-50).
4. Disconnect the ECM harness connector.
5. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the ECM (pins 34, 50, 54 and 70
of E-90).
6. Test for high resistance on each circuit.
7. Repair the connection(s) or circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 15 Go to Step 14
10 1. Turn OFF the ignition.
2. Disconnect the FRP sensor harness connector.
3. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the FRP sensor (pins 1, 2 and 3
of E-48).
4. Disconnect the ECM harness connector.
5. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the ECM (pins 47, 48, 68 and 69
of E-90).
6. Test for high resistance on each circuit.
7. Repair the connection(s) or circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 15 Go to Step 12
11 Notice:
An intermittent problem by foreign material
in the fuel is suspected.
Replace the fuel filter cartridge. Refer to Fuel Filter
Cartridge Replacement.
Did you complete the replacement? —
Go to Step 15
—
12Replace the FRP sensor. Refer to FRP sensor
Replacement.
Did you complete the replacement? —
Go to Step 15
—
13Important:
Replacement fuel injector must be
programmed.
Replace the appropriate fuel injector that does not
change engine speed when commanded OFF.
Refer to Fuel Injector Replacement/ Fuel Injector
ID Code Data Programming.
Did you complete the replacement? —
Go to Step 15
—
Step Action Value(s)Yes No
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-83
14Important:
The fuel supply pump must be timed to
the engine and adjustment value must be learned
to the ECM.
Notice: Always replace the fuel filter cartridge
when a fuel supply pump is replaced.
Replace the fuel supply pump and fuel filter
cartridge. Refer to Fuel Supply Pump Replacement
and Fuel Filter Cartridge Replacement.
Did you complete the replacement? —
Go to Step 15
—
15Notice:
There is a possibility that the pressure
limiter valve did not active.
Replace the pressure limiter valve. Refer to Fuel
Rail Replacement.
Did you complete the replacement? —
Go to Step 16
—
161. Reconnect all previously disconnected
harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the
vehicle within the conditions that you
observed from the Freeze Frame/ Failure
Records.
Did the DTC fail this ignition? —
Go to Step 2 Go to Step 17
17 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-85
41. Turn OFF the ignition.
2. Disconnect the FRP regulator harness connector.
3. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the FRP regulator (pins 1 and 2
of E-50).
4. Disconnect the ECM harness connector.
5. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the ECM (pins 34, 50, 54 and 70
of E-90).
6. Test for high resistance on each circuit.
7. Repair the connection(s) or circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 10 Go to Step 6
5 1. Turn OFF the ignition.
2. Disconnect the FRP sensor harness connector.
3. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the FRP sensor (pins 1, 2 and 3
of E-48).
4. Disconnect the ECM harness connector.
5. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the ECM (pins 47, 48, 68 and 69
of E-90).
6. Test for high resistance on each circuit.
7. Repair the connection(s) or circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 10 Go to Step 8
6 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
and Desired Fuel Rail Pressure Parameter
with a scan tool.
Does the Fuel Pressure parameter follow within the
specified value quick enough (compare with a
similar unit if available)? ±
5 MPa
( ± 725 psi)
Go to Step 7 Go to Step 9
7 Notice:
An intermittent problem by foreign material
in the fuel is suspected.
Replace the fuel filter cartridge. Refer to Fuel Filter
Cartridge Replacement.
Did you complete the replacement? —
Go to Step 10
—
8Replace the FRP sensor. Refer to FRP Sensor
Replacement.
Did you complete the replacement? —
Go to Step 10
—
Step Action Value(s)Yes No
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
6E-86 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
9Important:
The fuel supply pump must be timed to
the engine and adjustment value must be learned
to the ECM.
Notice: Always replace the fuel filter cartridge
when a fuel supply pump is replaced.
Replace the fuel supply pump and fuel filter
cartridge. Refer to Fuel Supply Pump Replacement
and Fuel Filter Cartridge Replacement.
Did you complete the replacement? —
Go to Step 10
—
101. Reconnect all previously disconnected
harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the
vehicle within the conditions that you
observed from the Freeze Frame/ Failure
Records.
Did the DTC fail this ignition? —
Go to Step 2 Go to Step 11
11 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007