2007 ISUZU KB P190 ECO mode

6E–104 ENGINE DRIVEABILITY AND EMISSIONS
Fuel Pressure Relief Procedure
1. Remove the fuel cap.
2. Remove the fuel pump relay from the underhood relay center.
3. Start the engine and alow it to stall.
4. Crank the engine for an additional 3 seconds.
Fuel Pressure Gauge Installation
1. Remove the fuel pressure fitting cap.
2. Install fuel pressure gauge 5-8840-0378-0 to the fuel feed line located in front of and above the right
side valve cover.
3. Reinstall the fuel pump relay.
Fuel System Electrical Test
Step Action Value(s) Yes No
1 Was the “On-Board Diagnostic (OBD) System Check” performed?
—Go to Step 2Go to
On Board
Diagnostic
(OBD) System Check
2 1. Using the Tech 2, ignition “On” and engine “On”. 2. Select the “Miscellaneous Test” and perform the“Fuel Pump Relay” in the “Relays”.
3. Operate the Tech 2 in accordance with procedure.
Was the fuel pump operated, when the Tech 2 is
operated? —Go to
Fuel
System
Diagnosis Go to Step 3
3 Check the “Fuel Pump” fuse (20A). If the fuse is burnt out, repair as necessary.
Was the problem found? — Verify repair Go to Step 4
4 Check for poor/faulty connection at the fuel pump, fuel pump relay or ECM connector. If a poor/faulty
connection is found, repair as necessary.
Was the problem found?
— Verify repair Go to Step 5
5 Using the DVM and check the fuel pump relay. 1. Ignition “Off”, engine “Off”.
2. Remove the fuel pump relay from the relay box.
3. Check the relay coil.
Was the DVM indicated specified value?
120 - 150ΩGo to Step 6 Replace fuel
pump relay and verify repair
11C56(J2)
F2
X2
Fuel Pump Relay
3
4 2
1
Ω
34

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ISUZU KB P190 2007

6E–108 ENGINE DRIVEABILITY AND EMISSIONS
FUEL SYSTEM DIAGNOSIS
Circuit Description
When the ignition switch is turned ON, the engine
control module (ECM) will turn ON the in-tank fuel
pump. The in-tank fuel pump will remain ON as long as
the engine is cranking or running and the ECM is
receiving 58X crankshaft position pulses. If there are no
58X crankshaft position pulses, the ECM will turn the in-
tank fuel pump OFF 2 seconds after the ignition switch
is turned ON or 2 seconds after the engine stops
running.
The in-tank fuel pump is an electric pump within an
integral reservoir. The in-tank fuel pump supplies fuel
through an in-line fuel filter to the fuel rail assembly. The
fuel pump is designed to provide fuel at a pressure
above the pressure needed by the fuel injectors. A fuel
pressure regulator, attached to the fuel rail, keeps the
fuel available to the fuel injectors at a regulated
pressure. Unused fuel is returned to the fuel tank by a
separate fuel return line.
Te s t D e s c r i p t i o n
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Connect the fuel pressure gauge to the fuel feed line as shown in the fuel system illustration. Wrap a shop
towel around the fuel pressure connection in order to
absorb any duel leakage that may occur when
installing the fuel pressure gauge. With the ignition
switch ON and the fuel pump running, the fuel
pressure indicated by the fuel pressure gauge
should be 283-376 kPa (41-55 psi). This pressure is
controlled by the amount of pressure the spring
inside the fuel pressure regulator can provide.
3. A fuel system that cannot maintain a constant fuel pressure has a leak in one or more of the following
areas:
• The fuel pump check valve.
• The fuel pump flex line.
• The valve or valve seat within the fuel pressure regulator.

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ISUZU KB P190 2007

ENGINE DRIVEABILITY AND EMISSIONS 6E–109
• The fuel injector(s).
4. Fuel pressure that drops off during acceleration, cruise, or hard cornering may case a lean condition.
A lean condition can cause a loss of power, surging,
or misfire. A lean condition can be diagnosed using a
Tech 2 Scan Tool.
Following are applicable to the vehicle with
closed Loop System:
If an extremely lean condition occurs, the oxygen
sensor(s) will stop toggling. The oxygen sensor
output voltage(s) will drop below 500 mV. Also, the
fuel injector pulse width will increase.
Important: Make sure the fuel system is not
operating in the “Fuel Cut-Off Mode.”
When the engine is at idle, the manifold pressure is
low (high vacuum). This low pressure (high vacuum)
is applied to the fuel pressure regulator diaphragm.
The low pressure (high vacuum) will offset the
pressure being applied to the fuel pressure regulator
diaphragm by the spring inside the fuel pressure
regulator. When this happens, the result is lower fuel
pressure. The fuel pressure at idle will vary slightly
as the barometric pressure changes, but the fuel
pressure at idle should always be less than the fuel
pressure noted in step 2 with the engine OFF.
16.Check the spark plug associated with a particular
fuel injector for fouling or saturation in order to
determine if that particular fuel injector is leaking. If
checking the spark plug associated with a particular
fuel injector for fouling or saturation does not
determine that a particular fuel injector is leaking,
use the following procedure:
• Remove the fuel rail, but leave the fuel lines and injectors connected to the fuel rail. Refer to Fuel
Rail Assembly in On-Vehicle Service .
• Lift the fuel rail just enough to leave the fuel injector nozzles in the fuel injector ports.
Caution: In order to reduce the risk of fire and
personal injury that may result from fuel
spraying on the engine, verify that the fuel rail is
positioned over the fuel injector ports and verify
that the fuel injector retaining clips are intact.
• Pressurize the fuel system by connecting a 20 amp fused jumper between B+ and the fuel
pump relay connector.
• Visually and physically inspect the fuel injector nozzles for leaks.
17.A rich condition may result from the fuel pressure being above 376 kPa (55 psi). A rich condition may
cause a 45 to set. Driveability conditions associated with rich conditions can include hard starting
(followed by black smoke) and a strong sulfur smell
in the exhaust.
20.This test determines if the high fuel pressure is due to a restricted fuel return line or if the high fuel
pressure is due to a faulty fuel pressure regulator.
21.A lean condition may result from fuel pressure below 333 kPa (48 psi). A lean condition may cause a 44 to
set. Driveability conditions associated with lean
conditions can include hard starting (when the
engine is cold), hesitation, poor driveability, lack of
power, surging, and misfiring.
22.Restricting the fuel return line causes the fuel pressure to rise above the regulated fuel pressure.
Command the fuel pump ON with the scan tool. The
fuel pressure should rise above 376 kPa (55 psi) as
the fuel return line becomes partially closed.
NOTE: Do not allow the fuel pressure to exceed 414
kPa (60 psi). Fuel pressure in excess of 414 kPa (60
psi) may damage the fuel pressure regulator. Caution: To reduce the risk of fire and personal
injury:
• It is necessary to relieve fuel system pressure before connecting a fuel pressure gauge.
Refer to Fuel Pressure Relief Procedure,
below.
• A small amount of fuel may be released when disconnecting the fuel lines. Cover fuel line
fittings with a shop towel before
disconnecting, to catch any fuel that may leak
out. Place the towel in an approved container
when the disconnect is completed.
Fuel Pressure Relief Procedure
1. Remove the fuel cap.
2. Located on the intake manifold which is at the top right part of the engine.
3. Start the engine and allow it to stall.
4. Crank the engine for an additional 3 seconds.
Fuel Pressure Gauge Installation
1. Remove the fuel pressure fitting cap.
2. Install fuel pressure gauge 5-8840-0378-0 to the fuel feed line located on the upper right side of the
engine.
3. Reinstall the fuel pump relay.

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6E–110 ENGINE DRIVEABILITY AND EMISSIONS
Fuel System Diagnosis
StepAction Value(s) Yes No
1 Was the “On-Board Diagnostic (OBD) System Check” performed? — Go to Step 2Go to
OBD
System Check
2 1. Turn the ignition OFF. 2. Turn the air conditioning system OFF.
3. Relieve fuel system pressure and install the fuel pressure gauge.
4. Turn the ignition ON.
NOTE: The fuel pump will run for approximately 2
seconds. Use the Scan Tool to command the fuel
pump ON.
5. Observe the fuel pressure indicated by the fuel pressure gauge with the fuel pump running.
Is the fuel pressure within the specified limits? 283-376 kPa
(41-55 psi) Go to Step 3Go to Step 17
3 Does the fuel pressure indicated by the fuel pressure gauge remain constant?
NOTE: The fuel pressure will drop when the fuel
pump stops running, then it should stabilize and
remain constant. — Go to Step 4Go to Step 12
4 1. When the vehicle is at normal operating temperature, turn the ignition ON to build fuel
pressure and observe the measurement on the
gauge.
2. Start the engine and observe the fuel pressure gauge.
Did the reading drop by the amount specified after the
engine was started? 21-105 kPa
(3-15 psi) Go to Step 5Go to Step 9
5 Is fuel pressure dropping off during acceleration, cruise, or hard cornering? — Go to Step 6Check for
improper fuel
6 Visually and physically inspect the following items for a restriction:
• The in-line fuel filter.
• The fuel feed line.
Was a restriction found? — Verify repair Go to Step 7
7 Remove the fuel tank and visually and physically inspect the following items:
• The fuel pump strainer for a restriction.
• The fuel line for a leak.
• Verify that the correct fuel pump is in the vehicle.
Was a problem found in any of these areas? — Verify repair Go to Step 8
8 Replace the fuel pump. Is the action complete? — Verify repair —
9 1. Disconnect the vacuum hose from the fuel pressure regulator.
2. With the engine idling, apply 12-14 inches of vacuum to the fuel pressure regulator.
Does the fuel pressure indicated by the fuel pressure
gauge drop by the amount specified? 21-105 kPa
(3-15 psi) Go to Step 10Go to Step 11

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ISUZU KB P190 2007

6E–112 ENGINE DRIVEABILITY AND EMISSIONS
22 1. Command the fuel pump ON with the Scan Tool.2. Using suitable pliers which will not damage thefuel hose, gradually apply pressure with the pliers
to pinch the flexible fuel return hose closed. 376 kPa
(55 psi)
Does the fuel pressure indicated by the fuel pressure
gauge rise above the first specified value?
Caution: Do not let the fuel pressure exceed the
second specified value. 414 kPa
(60 psi) Go to Step 11Go to Step 7
23 1. Command the fuel pump ON with the Scan Tool. 2. Remove the fuel filler cap and listen for the soundof the fuel pump running.
3. Turn the pump off.
Was the fuel pump running? — Go to Step 7Go to
Fuel
System
Electrical Test Chart
Step
Action Value(s) Yes No

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ISUZU KB P190 2007

ENGINE DRIVEABILITY AND EMISSIONS 6E–113
ECM DIAGNOSTIC TROUBLE CODES (DTC)Ty p e A
•Emission related.
• Requests illumination of the MIL (Malfunction Indicator Lamp = Check Engine Lamp) of the first trip with a fail.
• Stores a history DTC on the first trip.
• Stores a freeze frame (If empty).
• Stores a fail record.
• Updates the fail record each time the diagnostic test fails.
Ty p e B
•Emission related.
• “Armed” after one trip with fail.
• “Disarmed” after one trip with a pass.
• Requests illumination of the MIL on the second consecutive trip with a fail.
• Store a history DTC on the second consecutive trip with a fail. (The DTC will be armed after the first fail.)
• Stores a freeze frame on the second consecutive trip with a fail (If empty).
• Stores a fail record when the first test fails (not dependent on consecutive trip).
• Updates the fail record each time the diagnostic test fails.
Ty p e D
• Non emission related.
• Does not request illumination of any lamp.
• Stores a history DTC on the first trip.
• Does not store a freeze frame.
• Stores fail record when test fails.
• Updates the fail record each time the diagnostic test fails.

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6E–114 ENGINE DRIVEABILITY AND EMISSIONS
Code TypeDTC Name DTC Setting Condition Fail-Safe (Back Up)Recovery Condition Related Failure PartsRelated
ECM
Pin No.
P0107 A Manifold Absolute Pressure Circuit Low Input 1. No DTC relating to TPS.
2. Throttle position is more than 0% if engine speed is below 1000rpm, or throttle
position more than 5% if engine speed is
more than 1000rpm.
3. MAP sensor output is below 12kPa. The ECM uses default manifold
absolute pressure value based on
engine speed and throttle position. MAP sensor output is more than 12kPa. 1. Sensor power supply circuit open or short
to ground circuit.
2. Sensor signal circuit open or short to ground circuit.
3. Poor connector connection.
4. MAP sensor malfunction.
5. ECM malfunction. J1-24/
J1-31
P0108 A Manifold Absolute Pressure Circuit High Input 1. No DTC relating to TPS.
2. Throttle position is below 15% if engine speed is below 2500rpm, or throttle
position is below 35% if engine speed is
more than 2500rpm.
3. Engine run time is longer than 10 seconds.
4. MAP sensor output is more than 103kPa. MAP sensor output is below 103kPa. 1. Sensor power supply circuit short to
voltage circuit.
2. Sensor signal circuit short to voltage circuit.
3. Sensor ground circuit open or short to voltage circuit.
4. Poor connector connection.
5. MAP sensor malfunction.
6. ECM malfunction. J1-16/
J1-24/ J1-31
P0112 A Intake Air Temperature Sensor Low Input 1. No DTC relating to VSS. 2. Vehicle speed is more than 25km/h.
3. Engine run time is longer than 120 seconds.
4. IAT sensor output is more than 149 deg. C. The ECM uses 20 deg. C condition
as substitute. IAT sensor output is below 149 deg. C. 1. Sensor signal circuit short to ground
circuit.
2. IAT sensor malfunction.
3. ECM malfunction. J2-22
P0113 A Intake Air Temperature Sensor High Input 1. No DTC relating to VSS & ECT sensor. 2. Vehicle speed is below 70km/h.
3. 3Engine coolant temperature is more than -8 deg. C.
4. Engine run time is longer than 120 seconds.
5. Mass air flow is below 30g/s.
6. IAT sensor output is below -38 deg. C. IAT sensor output is more than -38 deg. C. 1. Sensor signal circuit open or short to
voltage circuit.
2. Sensor ground circuit open or short to voltage circuit.
3. Poor connector connection
4. IAT sensor malfunction.
5. ECM malfunction. J2-1/
J2-22
P0117 A Engine Coolant Temperature Sensor Low Input 1. Engine run time is longer than 120
seconds.
2. ECT sensor output is more than 149 deg. C. The ECM uses default engine
coolant temperature value based
on intake air temperature and
engine run time. ECT sensor output is below 149 deg. C. 1. Sensor signal circuit short to ground
circuit.
2. ECT sensor malfunction.
3. ECM malfunction. J1-27
P0118 A Engine Coolant Temperature Sensor High Input 1. Engine run time is longer than 120
seconds.
2. ECT sensor output is below -38 deg. C. ECT sensor output is more than -38 deg. C. 1. Sensor signal circuit open or short to
voltage circuit.
2. Sensor ground circuit open or short to voltage circuit.
3. Poor connector connection
4. ECT sensor malfunction.
5. ECM malfunction. J1-27/
J1-32

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ENGINE DRIVEABILITY AND EMISSIONS 6E–11 5
P0122 A Throttle Position Sensor Low Input TPS output voltage is below 0.14V. The ECM uses 0% condition as
substitute. TPS output voltage is more than 0.14V. 1. Sensor power supply circuit open or short
to ground circuit.
2. Sensor signal circuit open or short to ground circuit.
3. Poor connector connection.
4. TPS malfunction.
5. ECM malfunction. J1-7/
J1-15/
P0123 A Throttle Position Sensor High Input TPS output voltage is more than 4.9V. TPS output voltage is below 4.9V.1. Sensor power supply circuit short to
voltage circuit.
2. Sensor signal circuit short to voltage circuit.
3. Sensor ground circuit open or short to voltage circuit.
4. Poor connector connection.
5. TPS malfunction.
6. ECM malfunction. J1-7/
J1-15/ J1-32
P0131 A O
2 Sensor Circuit Low Voltage (Bank 1
Sensor 1) 1. No DTC relating to MAP sensor, TPS,
EVAP purge, ECT sensor, CKP sensor,
VSS, injector control circuit and ignition
control circuit.
2. Engine coolant temperature is more than 60 deg. C.
3. O
2 sensor bank 1 output voltage is below
50mV in “Closed Loop” condition. “Open Loop” fuel control. O
2 sensor bank 1 output voltage is more
than 50mV. 1. Sensor harness short to ground circuit.
2. O
2 sensor malfunction.
3. ECM malfunction. J2-6/
J2-21
P0132 A O
2 Sensor Circuit High Voltage (Bank 1
Sensor 1) 1. No DTC relating to MAP sensor, TPS,
EVAP purge, ECT sensor, CKP sensor,
VSS, injector control circuit and ignition
control circuit.
2. Engine coolant temperature is more than 60 deg. C.
3. O
2 sensor bank 1 output voltage is more
than 952mV in “Closed Loop” condition. O
2 sensor bank 1 output voltage is below
952mV. 1. Sensor harness short to voltage circuit.
2. O
2 sensor malfunction.
3. MAF sensor output is incorrect.
4. Air intake line malfunction.
5. IAC valve malfunction.
6. Incorrect fuel pressure.
7. Injector malfunction.
8. ECM malfunction. J2-6/
J2-21
P0134 A O
2 Sensor Circuit No Activity Detected
(Bank 1 Sensor 1) 1. No DTC relating to MAP sensor, TPS,
EVAP purge, ECT sensor, CKP sensor,
VSS, injector control circuit and ignition
control circuit.
2. Engine coolant temperature is more than 60 deg. C.
3. Engine run time is longer than 40 seconds.
4. Mass air flow is more than 7g/s.
5. O
2 sensor bank 1 output voltage is
between 300mV and 600mV. O
2 sensor bank 1 output voltage is below
3 0 0 m V c o n s e c u t i v e l y .
O R
O2 sensor bank 1 output voltage is more
than 600mV consecutively. 1. Sensor harness open circuit.
2. O
2 sensor malfunction.
3. MAF sensor output is incorrect.
4. Air intake line malfunction.
5. IAC valve malfunction.
6. Incorrect fuel pressure.
7. Injector malfunction.
8. ECM malfunction. J2-6/
J2-21
Code Type
DTC Name DTC Setting Condition Fail-Safe (Back Up)Recovery Condition Related Failure PartsRelated
ECM
Pin No.

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