ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-229
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 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 on 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 11
11 Replace the FRP sensor. Refer to FRP sensor
Replacement.
Did you complete the replacement? —
Go to Step 15
—
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 15
—
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 15
—
Step Action Value(s)Yes No
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ISUZU KB P190 2007
6E-232 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Notice:• This DTC most likely indicates a loss of fuel pressure by a fuel leak from the high pressure
side. Inspect the high pressure side fuel leakage
between the fuel supply pump and fuel injector
first. • 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 P1094
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. Inspect the high pressure side between the
fuel supply pump and the fuel injectors for fuel
leakage. The following components may
contain an external leak.
• Fuel supply pump
• Fuel rail
• Pressure limiter valve
• Fuel rail pressure (FRP) sensor
• Fuel pipe between the fuel supply pump and fuel rail
• Fuel pipe between the fuel rail and fuel injectors
• Each fuel pipe sleeve nuts
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.
Notice: Remove and inspect the inlet high
pressure joint to the fuel injectors for fuel leaking
from the sleeve nut(s). Replace the fuel injector
and injection pipe when foreign material was in
contact.
2. Repair any fuel system leaks as necessary.
Did you find and correct the condition? —
Go to Step 19 Go to Step 3
3 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 15 Go to Step 4
4 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 P0087, P0091, P0092, P0192, P0193,
P0201 - P0204, P1064, P1065, P124B or P2146 -
P2151 set? —
Go to Applicable DTC Go to Step 5
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ISUZU KB P190 2007
ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-233
51. 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 6 Go to Step 13
6 1. Turn OFF the ignition.
2. Place the transmission in Neutral and set the parking brake.
3. Start the engine and let idle for at least 3 minutes while observing the DTC Information
with a scan tool.
Does the DTC fail this ignition? —
Go to Step 8 Go to Step 7
7 1. Accelerate the engine between idle and
W.O.T. (accelerator pedal full travel) many
times.
2. Let idle for at least 3 minutes while observing the DTC Information with a scan tool.
Does the DTC fail this ignition? —
Go to Step 18 Go to Step 8
8 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 16 Go to Step 9
9 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. Repair or replace as necessary.
Did you find and correct the condition? —
Go to Step 19 Go to Step 10
Step
Action Value(s)Yes No
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ISUZU KB P190 2007
6E-234 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
10Notice:
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 19 Go to Step 11
11 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 19 Go to Step 12
Step
Action Value(s)Yes No
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ISUZU KB P190 2007
ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-235
121. 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 FRP regulator circuit.
7. Repair the connection(s) or circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 19 Go to Step 17
13 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 19 Go to Step 14
14 Replace the FRP sensor. Refer to FRP sensor
Replacement.
Did you complete the replacement? —
Go to Step 19
—
15Important:
Replacement fuel injector must be
programmed.
Replace the appropriate fuel injector that was
leaking fuel found at Step 3 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 19
—
16Important:
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 19
—
Step Action Value(s)Yes No
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ISUZU KB P190 2007
6E-238 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
41. Remove the intake duct that is connected to
the intake throttle valve.
2. Inspect the intake throttle valve for the following conditions:
• Restricted intake throttle valve by foreign materials
• Excessive deposits at throttle bore
• Bent butterfly valve
Notice: Replace the intake throttle valve if there is
any sticking.
3. Repair or replace as necessary.
Did you find and correct the condition? —
Go to Step 6 Go to Step 5
5 Replace the intake throttle valve. Refer to Intake
Throttle Valve Replacement.
Did you complete the replacement? —
Go to Step 6
—
61. 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 7 Go to Step 9
7 Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 8
—
81. 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 9
9 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
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ISUZU KB P190 2007
6E-240 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
31. Turn OFF the ignition.
2. Disconnect all fuel injector harness connectors.
3. Disconnect the ECM harness connector.
4. Measure continuity through the fuel injector harness connectors.
• #1 and #2 solenoid control circuits (pin 1 of E-13 and pin 1 of E-14)
• #1 and #2 charge voltage circuits (pin 2 of E-13 and pin 2 of E-14)
• #1 solenoid control circuit (pin 1 of E-13) and #2 charge voltage circuit (pin 2 of E-
14)
• #2 solenoid control circuit (pin 1 of E-14) and #1 charge voltage circuit (pin 2 of E-
13)
• #1 and #3 solenoid control circuits (pin 1 of E-13 and pin 1 of E-15)
• #1 and #3 charge voltage circuits (pin 2 of E-13 and pin 2 of E-15)
• #1 solenoid control circuit (pin 1 of E-13) and #3 charge voltage circuit (pin 2 of E-
15)
• #3 solenoid control circuit (pin 1 of E-15) and #1 charge voltage circuit (pin 2 of E-
13)
• #2 and #4 solenoid control circuits (pin 1 of E-14 and pin 1 of E-16)
• #2 and #4 charge voltage circuits (2 of E- 14 and pin 2 of E-16)
• #2 solenoid control circuit (pin 1 of E-14) and #4 charge voltage circuit (pin 2 of E-
16)
• #4 solenoid control circuit (pin 1 of E-16) and #2 charge voltage circuit (pin 2 of E-
14)
• #3 and #4 solenoid control circuits (pin 1 of E-15 and pin 1 of E-16)
• #3 and #4 charge voltage circuits (pin 2 and of E-15 and pin 2 of E-16)
• #3 solenoid control circuit (pin 1 of E-15) and #4 charge voltage circuit (pin 2 of E-
16)
• #4 solenoid control circuit (pin 1 of E-16) and #3 charge voltage circuit (pin 2 of E-
15)
5. Repair the short circuit if continuity exists for any measurement.
Did you find and correct the condition? —
Go to Step 5 Go to Step 4
4 Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 5
—
Step Action Value(s)Yes No
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ISUZU KB P190 2007
ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-243
31. Inspect for an intermittent, for poor tightening
and corrosion at the engine ground terminal
(E-10).
2. Repair the tightening or clean the corrosion as necessary.
Did you find and correct the condition? —
Go to Step 8 Go to Step 4
4 1. Test ground circuit between the ECM (pin 73
of E-90) and the engine ground terminal (E-
10) for an intermittently open circuit or high
resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 8 Go to Step 5
5 1. Test the battery voltage feed circuit between
the ECM (pin 73 of E-90) and the ECM main
relay (pin 1 of X-12) for an intermittently open
circuit or high resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 8 Go to Step 6
6 1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the ECM (pin 73 of C-58 and pin
73 of E-90).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 8 Go to Step 7
7 Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 8
—
81. Reconnect all previously disconnected relay
or 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 3 Go to Step 9
9 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
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ISUZU KB P190 2007