ISUZU KB P190 2007 Workshop Repair Manual

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

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

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

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

6E-88 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
61. Turn OFF the ignition for 30 seconds.
2. Disconnect the FRP regulator harness connector.
3. Connect a test lamp between the high side circuit (pin 1 of E-50) and a known good
ground.
4. Turn ON the ignition, with the engine OFF. DO NOT start the engine.
Does the test lamp illuminate then go out? —
Go to Step 7 Go to Step 10
7 1. Turn OFF the ignition for 30 seconds.
2. Connect a test lamp between the low side circuit (pin 2 of E-50) and battery voltage.
3. Turn ON the ignition, with the engine OFF. DO NOT start the engine.
Does the test lamp illuminate then go out? —
Go to Step 12 Go to Step 11
8 1. Test the high side circuits between the ECM
(pins 34 and 54 of E-90) and the FRP
regulator (pin 1 of E-50) for a short to battery
or ignition voltage.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 16 Go to Step 15
9 1. Test the low side circuits between the ECM
(pins 50 and 70 of E-90) and the FRP
regulator (pin 2 of E-50) for a short to ground.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 16 Go to Step 15
10 1. Test the high side circuits between the ECM
(pins 34 and 54 of E-90) and the FRP
regulator (pin 1 of E-50) for the following
conditions:
• An open circuit
• A short to ground
• A short to the low side circuit
• High resistance
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 16 Go to Step 13
11 Important:
The ECM may be damaged if the FRP
regulator low side circuit is shorted to a voltage
source.
1. Test the low side circuits between the ECM (pins 50 and 70 of E-90) and the FRP
regulator (pin 2 of E-50) for the following
conditions:
• An open circuit
• A short to battery or ignition voltage
• High resistance
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 16 Go to Step 13
Step
Action Value(s)Yes No

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-89
121. Inspect for an intermittent and for poor
connections at the harness connector of the
FRP regulator (pins 1 and 2 of E-50).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 16 Go to Step 14
13 1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for poor connections at the harness connector of the
ECM (pins 34, 50, 54 and 70 of E-90).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 16 Go to Step 15
14 Replace the FRP regulator. Refer to Fuel Pump
Replacement.
Did you complete the replacement? —
Go to Step 16
—
15Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM 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 3 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

6E-90 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0093 (Flash Code 227)
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 rail pressure is certain pressure
low as compared with the engine speed, this DTC will
set.
Condition for Running the DTC • DTC P0087, 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 lower than 15 MPa (2,180 psi) for longer than 5
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 low 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.
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 P0093
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

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-91
21. 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 16 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 13 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
5 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 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 11
Step
Action Value(s)Yes No

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

6E-92 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
61. Turn OFF the ignition.
2. Place the transmission in Neutral and set the parking brake.
3. Start the engine.
4. Perform the Cylinder Balance Test with a scan tool.
5. 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 14 Go to Step 7
7 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 16 Go to Step 8
8 Notice:
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 16 Go to Step 9
Step
Action Value(s)Yes No

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-93
91. 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 16 Go to Step 10
10 1. 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 16 Go to Step 15
11 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 16 Go to Step 12
Step
Action Value(s)Yes No

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007