2007 ISUZU KB P190 fuse

6E-60 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Lost Communication with The Engine Control Module (ECM)
Circuit Description
The ECM, transmission control module (TCM) (AISIN
A/T only) and immobilizer control unit (ICU) all
communicate with the scan tool over the controller area
network (CAN) link. The ECM, TCM, ICU and the data
recording module (DRM) communicate with each other
over the same CAN link. If no immobilizer system is
installed, the instrument panel (IP) cluster has a CAN
terminating resistor instead of the ICU. Schematic Reference:
Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing Lost Communication with The Engine Control Module (ECM)
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 Attempt to establish communication with the ECM.
Does the scan tool communicate with the ECM? —Go to Intermittent
Conditions Go to Step 3
3 Check the ECM C-58 and E-90 connectors for poor
connections.
Did you find and correct the condition? —
Go to Step 16 Go to Step 4
4 1. Check the ECM (40A) slow blow fuse, ECM
(B) (10A) fuse and Engine (10A) fuse.
Replace and retest if open. If any fuse
continues to open, repair the short to ground
on each circuit fed by that fuse.
2. Turn OFF the ignition.
3. Disconnect the ECM C-58 harness connector.
4. Turn ON the ignition, with the engine OFF.
5. Connect a test lamp to ground and check for voltage at the ignition voltage supply circuit at
the ECM (pin 72 of C-58).
Does the test lamp illuminate? —
Go to Step 5 Go to Step 13
5 1. Turn OFF the ignition.
2. Disconnect the scan tool from the data link connector (DLC) if connected.
3. Measure the resistance across the CAN Low and High circuits by probing the DLC (pins 6
and 14 of B-58).
Is the resistance within the specified value (parallel
resistance of the 120 Ω resistor in the ECM and the
120 Ω resistor in the ICU or IP cluster should be
60 Ω)? 50 to 70
Ω
Go to Step 7 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 (pins 66 and 67 of C-
58).
4. Test for high resistance on each circuit.
5. Repair the connection(s) or circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 16 Go to Step 15

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ISUZU KB P190 2007

6E-62 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
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. Turn OFF the ignition.
2. Reconnect all previously disconnected fuse, relay or harness connector(s).
3. Turn ON the ignition, with the engine OFF.
4. Attempt to establish communication with the ECM.
Does the scan tool communicate with the ECM? —
System OK Go to Step 3
Step
Action Value(s)Yes No

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-63
Engine Cranks but Does Not Run
Description
The Engine Cranks but Does Not Run diagnostic table
is an organized approach to identifying a condition that
causes an engine to not start. The diagnostic table
directs the service technician to the appropriate system
diagnosis. The diagnostic table assumes the following
conditions are met:
• The battery is completely charged and terminals are cleaned and tight.
• The engine cranking speed is normal.
• There is adequate fuel in the fuel tank.
• There is no fuel leak in the fuel line.
• There is no air in the fuel line.
• Filters (air, fuel) are clean.
• Fuse and slow blow fuse are normal. 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.
5. If the fuel rail pressure (FRP) regulator low side
circuits between the ECM and the FRP regulator are
shorted to ground, FRP Regulator Feedback will be
approximately 400mA lower as compared with normal.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing Engine Cranks but Does Not Run (1of 2)
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. Crank the engine for the specified amount of time.
4. Monitor the DTC Information with a scan tool.
Does the scan tool display any DTCs that failed this
ignition? 15 seconds
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 parameter with a scan tool.
Does the scan tool indicate the specified value? 0 MPa (0 psi)
Go to Step 4 Go to Step 6
4 Notice:
If the vehicle has run out of fuel, air may
be trapped in the fuel system.
1. Make sure the fuel tank have adequate fuel and the fuel quality is good (take a sample).
2. Observe the Fuel Rail Pressure parameter on the scan tool while cranking over the engine
for 5 seconds.
Does the scan tool indicate more than the specified
value during crank? 20 MPa (2,900
psi)
Go to Step 9 Go to Step 5
5 Observe the FRP Regulator Feedback parameter
on the scan tool while cranking over the engine for
5 seconds.
Does the scan tool indicate more than the specified
value during crank? 1500 mA
Go to 2 of 2 Step 1 Go to Step 8

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ISUZU KB P190 2007

6E-66 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
4Notice:
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 12 Go to Step 5
5 1. Turn OFF the ignition.
2. Remove the Fuel Pump (10A) fuse from the engine room fuse block in order to disable in-
tank fuel pump.
3. Disconnect each fuel injector harness connector from all fuel injectors in order to
disable injection.
4. Remove the rubber fuel hose from the leak-off pipe. Then, remove the leak-off pipe assembly
from the engine that is jointed to the fuel
supply pump and the pressure limiter valve.
Use a pan to catch the fuel from the removed
fuel line.
5. Crank over the engine while observing the fuel leak from the pressure limiter valve.
Important: Safety glasses must be worm. Fuel
may splash if the pressure limiter valve is faulty.
Is there fuel leak from the pressure limiter valve? —
Go to Step 11 Go to Step 6
Step
Action Value(s)Yes No

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ISUZU KB P190 2007

6E-72 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
41. Connect a test lamp between the control
circuit (pin 1 of E-106) and battery voltage.
2. Perform the Turbocharger Solenoid Control with a scan tool.
3. Command the solenoid valve Increase and Decrease while observing the test lamp.
Does the test lamp change brightness when
commanded Increase and Decrease? —
Go to Step 7 Go to Step 6
5 Repair the open circuit or high resistance between
the Engine (10A) fuse and the solenoid valve (pin 2
of E-106). Check the Engine (10A) fuse first.
Did you complete the repair? —
Go to Step 11
—
61. Test the control circuit between the ECM (pin
66 of E-90) and the solenoid valve (pin 1 of E-
106) for the following conditions:
• An open circuit
• A short to ground
• 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 11 Go to Step 8
7 1. Inspect for an intermittent and for poor
connections at the harness connector of the
solenoid valve (pins 1 and 2 of E-106).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 9
8 1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for a poor connection at the harness connector of the
ECM (pin 66 of E-90).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 10
9 Replace the turbocharger nozzle control solenoid
valve.
Did you complete the replacement? —
Go to Step 11
—
10Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 11
—
111. Reconnect all previously disconnected fuse 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 12
Step Action Value(s) Yes No

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ISUZU KB P190 2007

6E-98 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0102 or P0103 (Flash Code 91)
Circuit Description
The mass air flow (MAF) sensor is an air flow meter
that measures the amount of air that enters the engine.
It is fitted between the air cleaner and turbocharger. A
small quantity of air that enters the engine indicates
deceleration or idle speed. A large quantity of air that
enters the engine indicates acceleration or a high load
condition. The sensor has the following circuits.
• Ignition voltage circuit
• Low reference circuit
• MAF sensor signal circuit
The ECM monitors the MAF sensor signal voltage. This
output voltage will display on the scan tool as a voltage
parameter and as a grams per second (g/s) parameter.
If the ECM detects an excessively low or high signal
voltage, DTC P0102 or P0103 will set.
Condition for Running the DTC • The battery voltage is between 11.5 to 16.0 volts.
• The ignition switch is ON.
• The engine is running.
Condition for Setting the DTC • The ECM detects that the MAF sensor signal voltage is less than 0.1 volts. (DTC P0102)
• The ECM detects that the MAF sensor signal voltage is more than 4.9 volts for 3 seconds. (DTC
P0103)
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 uses a MAF substitution of default value.
• The ECM limits fuel injection quantity.
• The ECM inhibits pilot injection.
• The ECM inhibits EGR control.
• 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.
Notice: • The MAF Sensor parameter on scan tool will only update with engine running or one time after the
key is cycled when the ignition has been turned
OFF for longer than 10 seconds.
Test description
The number below refers to the step number on the
Circuit/ System Testing.
DTC P0102
4. This step tests for proper operation of the circuit in
the signal circuit. If the fuse in the jumper opens when
you perform this test, the signal circuit is shorted to
ground or low reference circuits.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0102
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. Observe the Mass Air Flow (MAF) Sensor parameter with a scan tool.
Is the MAF Sensor parameter less than the
specified value? 0.1 volts
Go to Step 3 Go to Diagnostic
Aids

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-99
31. Turn OFF the ignition.
2. Disconnect the MAF sensor harness connector.
3. Connect a test lamp between the ignition voltage feed circuit (pin 1 of E-47) and a
known good ground.
4. Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate? —
Go to Step 4 Go to Step 5
4 1. Turn OFF the ignition for 30 seconds.
2. Connect a 3-amp fused jumper wire between the ignition voltage feed circuit and the signal
circuit (pins 1 and 3 of E-47).
3. Turn ON the ignition, with the engine OFF.
Is the MAF Sensor parameter more than the
specified value? 4.9 volts
Go to Step 7 Go to Step 6
5 Repair the open circuit or high resistance between
the ECM Main Relay (pin 1 of X-12) and the MAF
sensor (pin 1 of E-47) for and open circuit or high
resistance. Check the Engine (10A) fuse first.
Did you complete the repair? —
Go to Step 11
—
61. Test the signal circuit between the ECM (pin
40 of E-90) and the MAF sensor (pin 3 of E-
47) for the following conditions:
• An open circuit
• A short to ground
• A short to the low reference circuit
• High resistance
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 8
7 1. Inspect for an intermittent and for poor
connections at the harness connector of the
MAF sensor (pins 1 and 3 of E-47).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 9
8 1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for a poor connection at the harness connector of the
ECM (pin 40 of E-90).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 10
9 Replace the MAF sensor. Refer to MAF Sensor
Replacement.
Did you complete the replacement? —
Go to Step 11
—
10Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 11
—
Step Action Value(s)Yes No

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ISUZU KB P190 2007

6E-100 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Circuit/ System Testing DTC P0103
111. Reconnect all previously disconnected fuse,
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 2 Go to Step 12
12 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
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. Observe the Mass Air Flow (MAF) Sensor parameter with a scan tool.
Is the MAF Sensor parameter more than the
specified value? 4.9 volts
Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition for 30 seconds.
2. Disconnect the MAF sensor harness connector.
3. Turn ON the ignition, with the engine OFF.
Is the MAF Sensor parameter less than the
specified value? 0.1 volts
Go to Step 4 Go to Step 5
4 Connect a test lamp between the low reference
circuit (pin 2 of E-47) and battery voltage.
Does the test lamp illuminate? —
Go to Step 7 Go to Step 6
5 1. Test the signal circuit between the ECM (pin
40 of E-90) and the MAF sensor (pin 3 of E-
47) for the following conditions:
• A short to battery or ignition voltage
• A short to any 5 volts reference
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 10
6 1. Test the low reference circuit between the
ECM (pin 43 of E-90) and the MAF sensor (pin
2 of E-47) for an open circuit or high
resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 8

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ISUZU KB P190 2007