2007 ISUZU KB P190 display

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-51
Turbocharger Solenoid Command
This parameter displays the turbocharger nozzle
control solenoid valve control duty ratio based on inputs
to the ECM from various engine sensors. The scan
tool will display a lower percentage when the nozzle is
controlled to open (vacuum pressure supply to the
actuator is reduced). The scan tool will display a higher
percentage when the nozzle is controlled to close
(vacuum pressure supply to the actuator is increased).
Desired Boost Pressure
This parameter displays boost pressure desired by the
ECM based on current driving conditions. This can be
compared to the actual boost pressure to determine
sensor accuracy or turbocharger control problems.
Boost Pressure
This parameter displays the boost pressure in the
intake duct as calculated by the ECM using the signal
from the boost pressure sensor. The scan tool will
display a low boost pressure when the low engine load,
and a high boost pressure when the high engine load.
Note that the true boost pressure is determined by
subtracting barometric pressure from the actual
reading.
Boost Pressure Sensor
This parameter displays the voltage signal sent to the
ECM from the boost pressure sensor. Boost pressure
sensor is a range of value indicating a low voltage
when the boost pressure is low (idle or lower engine
load) and a high voltage when the boost pressure is
high (higher engine load).
Desired Fuel Rail Pressure
This parameter displays fuel rail pressure desired by
the ECM based on current driving conditions. This can
be compared to the actual fuel rail pressure to
determine sensor accuracy or fuel pressure control
problems.
Fuel Rail Pressure
This parameter displays the fuel rail pressure as
calculated by the ECM using the signal from the fuel
rail pressure (FRP) sensor. The scan tool will display a
low pressure when the low engine load, and a high
pressure when the high engine load.
Fuel Rail Pressure Sensor
This parameter displays the voltage signal sent to the
ECM from the fuel rail pressure (FRP) sensor. FRP
sensor is a range of value indicating a low voltage
when the fuel rail pressure is low, and a high voltage
when the fuel rail pressure is high.
FRP Commanded Fuel Flow (Fuel Rail Pressure)
This parameter displays the commanded fuel flow
quantity of the fuel rail pressure (FRP) regulator to the
fuel rail. FRP Regulator Command (Fuel Rail Pressure)
This parameter displays the fuel rail pressure (FRP)
regulator control duty ratio based on inputs to the ECM
from various engine sensors. The scan tool will display
a lower percentage when the FRP regulator is
controlled to open (fuel supply quantity to the fuel rail is
increased). The scan tool will display higher
percentage when the FRP regulator is controlled to
close (fuel supply quantity to the fuel rail is reduced).
FRP Regulator Feedback (Fuel Rail Pressure)
This parameter displays the fuel rail pressure (FRP)
regulator control feedback current as measured by the
ECM. The scan tool will display a low current when the
FRP regulator is controlled to open (fuel supply
quantity to the fuel rail is increased). The scan tool will
display a high current when the FRP regulator is
controlled to close (fuel supply quantity to the fuel rail is
reduced).
Accelerator Pedal Position
This parameter displays the angle of the accelerator
pedal as calculated by the ECM using the signals from
the accelerator pedal position (APP) sensors. The scan
tool will display linearly from 0 to 100% according to the
pedal operation.
APP Sensor 1 (Accelerator Pedal Position)
This parameter displays the voltage signal sent to the
ECM from the accelerator pedal position (APP) sensor
1 of the APP sensor assembly. APP sensor 1 is a
range of value indicating a low voltage when the
accelerator pedal is not depressed, and a high voltage
when the accelerator pedal is fully depressed.
APP Sensor 2 (Accelerator Pedal Position)
This parameter displays the voltage signal sent to the
ECM from the accelerator pedal position (APP) sensor
2 of the APP sensor assembly. APP sensor 2 is a
range of value indicating a high voltage when the
accelerator pedal is not depressed, and a low voltage
when the accelerator pedal is fully depressed.
APP Sensor 3 (Accelerator Pedal Position)
This parameter displays the voltage signal sent to the
ECM from the accelerator pedal position (APP) sensor
3 of the APP sensor assembly. APP sensor 3 is a
range of value indicating a high voltage when the
accelerator pedal is not depressed, and a middle
voltage when the accelerator pedal is fully depressed.
EGR Solenoid Command
This parameter displays the EGR solenoid valve
control duty ratio based on inputs to the ECM from
various engine sensors. The scan tool will display a
lower percentage when the EGR solenoid valve is
controlled to close (EGR gas supply to the intake is
reduced). The scan tool will display a higher
percentage when the EGR solenoid valve is controlled
to open (EGR gas supply to the intake is increased).

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ISUZU KB P190 2007

6E-52 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Desired EGR Position
This parameter displays EGR position desired by the
ECM based on current driving conditions. This can be
compared to the actual EGR position to determine
sensor accuracy or EGR control problems.
EGR Position
This parameter displays the EGR valve position
calculated by the ECM using the signal from EGR
position sensor. The scan tool will display a low
percentage when the EGR valve is closed, and a high
percentage when the ERG valve is opened.
EGR Position Sensor
This parameter displays the voltage signal sent to the
ECM from the EGR position sensor. EGR position
sensor is a range of value indicating a low voltage
when the EGR valve is closed, and a high voltage when
the EGR valve is opened.
Intake Throttle Solenoid Command
This parameter displays the intake throttle solenoid
valve control duty ratio based on inputs to the ECM
from various engine sensors. The scan tool will display
a lower percentage when the intake throttle solenoid
valve is controlled to open. The scan tool will display a
higher percentage when the intake throttle solenoid
valve is controlled to close.
Desired Intake Throttle Position
This parameter displays intake throttle position desired
by the ECM based on current driving conditions. This
can be compared to the actual intake throttle position to
determine sensor accuracy or intake throttle control
problems.
Intake Throttle Position
This parameter displays the intake throttle valve
position calculated by the ECM using the signal from
intake throttle position sensor. The scan tool will display
a low percentage when the intake throttle valve is
closed, and a high percentage when the intake throttle
valve is opened. Note that the intake throttle position
indicates over 100% if the solenoid is commanded
OFF.
Intake Throttle Position Sensor
This parameter displays the voltage signal sent to the
ECM from the intake throttle position sensor. Intake
throttle position sensor is a range of value indicating a
low voltage when the intake throttle valve is closed to a
high voltage when the intake throttle valve is opened.
Desired Injection Quantity
This parameter displays a total injection quantity (main
injection quantity + pre injection quantity) desired by
the ECM based on current driving conditions.
Main Injection Quantity
This parameter displays a main injection quantity
desired by the ECM based on current driving
conditions. Main Injection Timing
This parameter displays a main injection timing desired
by the ECM based on current driving conditions.
Main Injection On Time
This parameter displays the time the ECM turns ON the
fuel injectors. The scan tool will display a higher value
with a longer pulse width, or a lower value with a
shorter pulse width.
Pre Injection Quantity
This parameter displays a pilot injection quantity
desired by the ECM based on current driving
conditions.
Pre Injection Interval
This parameter displays a injection interval between
end of pilot injection and start of main injection desired
by the ECM based on current driving condition.
Fuel Compensation Cyl. 1 to 4
This parameter displays the adjustment of fuel volume
for each cylinder at low engine speed area as
calculated by the ECM. The scan tool will display a
negative value if the fuel volume is lowered. The scan
tool will display a positive value if the fuel volume is
increased. If there is a cylinder that is excessively high
or low value, it may indicate faulty fuel injector, weak or
slightly seized cylinder or an incorrectly programmed
fuel injector ID code.
Cylinder Balancing Update
This parameter displays the state of the fuel
compensation for each cylinder. Enabled indicates the
adjustment of fuel volume for each cylinder is being
executed by the ECM when the engine is idle speed,
the engine coolant temperature sensor, the intake air
temperature sensor, barometric pressure sensor and
the vehicle speed sensor inputs are normal state.
Fuel Supply Pump Status
This parameter displays the learning state of the fuel
supply pump. Not Learn indicates initialized state that is
replaced to a new ECM or adjustment value is reset.
After engine is warm upped, leaning will start at idle
speed. Learning indicates learning state. Learned
indicates learning process is completed state.
Rail Pressure Feedback Mode
This parameter displays the state of the fuel rail
pressure feedback to the ECM. Wait Mode indicates
the ignition switch is turned ON position. Feedback
Mode indicates the engine is during crank or run.
Shutoff Mode indicates the ignition switch is turned
OFF position.
Engine Mode
This parameter displays the state of engine. Ignition On
indicates the ignition switch is turned ON position.
Cranking indicates the engine is during crank. Running
indicates the engine is run. Off indicates the ignition
switch is tuned OFF position.

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-53
Cam/ Crank Sensor Signal/ Synchronization Status
This parameter displays the synchronization state of
the crankshaft position (CKP) sensor signal and
camshaft position (CMP) sensor signal. Asynchronous
indicates the CMP sensor signal is not detected or only
CKP sensor signal is detected. No Crank Signal
indicates CMP sensor signal is detected but CKP
sensor signal is not detected. Synchronous indicates
both sensor signals are detected correctly.
Engine Runtime
This parameter displays the time elapsed since the
engine start. The scan tool will display the time in
hours, minutes and seconds. The engine run time will
reset to zero as soon as the ignition switch is OFF.
Vehicle Speed
This parameter indicates the vehicle speed calculated
by the ECM using the signal from the vehicle speed
sensor (VSS). The scan tool will display a low value at
lower vehicle speeds, and a high value at higher
vehicle speeds.
Transmission Gear
This parameter displays the estimated transmission
gear position as calculated by the ECM based on
inputs from the vehicle speed and the engine speed.
Starter Switch
This parameter displays the input status of the starter
switch to the ECM. When the ignition switch is turned at
START position, the scan tool displays On.
Ignition Switch
This parameter displays the input status of the ignition
switch to the ECM. When the ignition switch is turned
ON position, the scan tool displays On.
Ignition Voltage
This parameter displays the ignition voltage measured
at the ignition feed circuit of the ECM. Voltage is
applied to the ECM when the ignition switch is ON
position.
Battery Voltage
This parameter displays the battery voltage measured
at the ECM main relay switched voltage feed circuit of
the ECM. Voltage is applied to the ECM when the ECM
main relay is energized.
Fuel Pump Relay Command
This parameter displays the commanded state of the
fuel pump relay control circuit. On indicates the fuel
pump relay control circuit is being grounded by the
ECM, allowing fuel pumping from the tank.
Swirl Control Solenoid Command
This parameter displays the commanded state of the
swirl control solenoid control circuit. On indicates the
swirl control solenoid control circuit is being grounded
by the ECM, allowing vacuum pressure to the swirl
control
actuator. Fuel Filter Switch
This parameter displays the input state of the fuel
pressure switch to the ECM. When the large vacuum
pressure is generated in the fuel suction line such as
clogged fuel filter, the scan tool displays Off.
A/C Request Signal
This parameter displays the input state of the air
conditioning (A/C) request to the ECM from the
heating, ventilation, and air conditioning (HVAC)
controls. When the HVAC system is requesting to
ground the A/C compressor clutch, the scan tool
displays On.
A/C Relay Command
This parameter displays the commanded state of the A/
C compressor relay control circuit. On indicates the A/C
compressor relay control circuit is being grounded by
the ECM, allowing voltage to the A/C compressor.
Park/ Neutral Switch
This parameter displays the input state of the neutral
switch to the ECM. When the transmission gear is Park
or Neutral, the scan tool displays Neutral.
Glow Relay Command
This parameter displays the commanded state of the
glow relay control circuit. On indicates the glow relay
control circuit is being grounded by the ECM, allowing
voltage to the glow plugs.
Glow Plug Lamp Command
This parameter displays the commanded state of the
glow indicator lamp control circuit. The glow indicator
lamp should be On when the scan tool indicates
command On. The glow indicator lamp should be Off
when the scan tool indicates command Off.
Brake Switch 1
This parameter displays the input state of the brake
pedal switch 1 to the ECM. When the brake pedal is
depressed, scan tool displays Applied.
Brake Switch 2
This parameter displays the input state of the brake
pedal switch 2 to the ECM. When the brake pedal is
depressed, scan tool displays Applied.
Clutch Pedal Switch
This parameter displays the input state of the clutch
pedal switch to the ECM. When the clutch pedal is
depressed, scan tool displays Applied.
Cruise Main Lamp Command
This parameter displays the commanded state of the
cruise main lamp control circuit. The cruise main lamp
should be On when the scan tool indicates command
On. The cruise main lamp should be Off when the scan
tool indicates command Off.
Cruise Main Switch
This parameter displays the input state of the cruise
main switch to the ECM. When the Cruise Main switch
is pushed, the scan tool displays On.

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ISUZU KB P190 2007

6E-54 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Cruise Cancel Switch
This parameter displays the input state of the cruise
cancel switch to the ECM. When the Cruise Cancel
switch is applied, the scan tool displays Off.
Cruise Resume Switch
This parameter displays the input state of the cruise
resume/accel. switch to the ECM. When the Cruise
Resume/Accel. switch is applied, the scan tool displays
On.
Cruise Set Switch
This parameter displays the input state of the cruise
set/coast switch to the ECM. When the Cruise Set/
Coast switch is pushed, the scan tool displays On.
MIL Command (Malfunction Indicator Lamp)
This parameter displays the commanded state of the
malfunction indicator lamp (MIL) control circuit. The
MIL should be On when the scan tool indicates
command On. The MIL should be Off when the scan
tool indicates command Off.
SVS Lamp Command (Service Vehicle Soon)
This parameter displays the commanded state of the
service vehicle soon (SVS) lamp control circuit. The
SVS lamp should be On when the scan tool indicates
command On. The SVS lamp should be Off when the
scan tool indicates command Off.
Limp Home Mode
This parameter indicates the state of the limp-home
mode. None indicates limp-home mode is not applied.
1, 2, 3 and 4 indicates fuel injection quantity reduction
is applied. 2 or higher number inhibits pilot injection. If 4
is indicated, engine running will be stopped when the
vehicle speed is less than 5 km/h (3 MPH) for 5
seconds.
Distance While MIL is Activated
This parameter displays the mileage since the
malfunction indicator lamp (MIL) is turned ON.
Engine Runtime With MIL Active
This parameter displays the engine run time elapsed
since the malfunction indicator lamp (MIL) is turned
ON. The scan tool will display the time in minutes.
Total Engine Overspeed Event
This parameter indicates counter of engine overspeed
event. Counter will be zero if any DTC is cleared.
Total Engine Coolant Overtemperature Event
This parameter indicates counter of engine overheat
event. The counter is active if engine coolant is over
11 0 °C (230 °F). Counter will be zero if any DTC is
cleared. Total Fuel Temperature Overtemperature Event
This parameter indicates counter of fuel temperature
excessively high condition. The counter is active if fuel
temperature is over 95 °C (203 °F). Counter will be zero
if any DTC is cleared.
Total Intake Air Temperature Overtemperature
Event
This parameter indicates counter of intake air
temperature excessively high condition. The counter is
active if intake air temperature is over 55 °C (131 °F).
Counter will be zero if any DTC is cleared.
Immobilizer Function Programmed
This parameter displays the state of the immobilizer
function programming in the ECM. The scan tool will
display Yes or No. Yes indicates the immobilizer
security information is correctly programmed in the
ECM. No indicates the ECM is not programmed or
ECM is reset.
Wrong Immobilizer Signal
This parameter displays the input state of the received
response signal to the ECM. When the ECM received
wrong response signal from the immobilizer control unit
(ICU), the scan tool displays Yes.
Immobilizer Signal
This parameter displays the input state of the response
signal to the ECM. When the ECM received any
response signal from the immobilizer control unit (ICU),
the scan tool displays Yes.
Security Wait Time
This parameter displays the security wait time length in
the ECM. Inactive indicates not in security wait time.
Time indicates under security wait time. This wait time
stage will prevent any further attempts to enter the
security code until the wait time has elapsed. The wait
time will increase each time an incorrect security code
is entered. Note that this parameter is not count
downed. It keeps displaying the same time until that
wait time has elapsed. The ignition switch must be kept
at ON position during the wait time period.

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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-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

6E-172 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0500 (Flash Code 25)
Circuit Description
The vehicle speed sensor (VSS) is used by the ECM
and speedometer, which generates a speed signal from
the transmission output shaft rotational speed or
transfer output shaft rotational speed. The sensor has
the following circuits.
• Ignition voltage circuit
• Low reference circuit
• VSS signal circuit
The VSS uses a hall effect element. It interacts with the
magnetic field created by the rotating magnet and
outputs square wave pulse signal. The ECM calculates
the vehicle speed by the VSS. If the 2WD fitted with
Jatco automatic transmission, VSS signals are sent
from the TCM. If the ECM detects VSS signals are not
generated, this DTC will set.
Condition for Running the DTC • The ignition voltage is more than 9 volts.
• The ignition switch is ON.
• The engine speed is more than 1000 RPM.
• The commanded fuel injection quantity is OFF (accelerator pedal is not depressed). Condition for Setting the DTC
• The ECM detects that the VSS signals are not generated for 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 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.
• Electromagnetic interference in the VSS circuits may set this DTC.
Notice: • If this DTC set, the Vehicle Speed parameter on the scan tool will display 3 km/h (2 MPH).
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0500 (2WD fitted with Jatco A/T)
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.
Is DTC P0219 also set? —
Go to DTC P0219 Go to Step 3
3 Monitor the transmission DTC Information with a
scan tool.
Is DTC P0722 set? —Go to P0722 in
Automatic
Transmission
Section Go to Step 4
4 Drive the vehicle while observing the Vehicle
Speed parameter with a scan tool.
Does the scan tool indicate correct vehicle speed? —
Go to Diagnostic
Aids Go to Step 5

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ISUZU KB P190 2007

6E-176 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0501 (Flash Code 25)
Circuit Description
The vehicle speed sensor (VSS) is used by the ECM
and speedometer, which generates a speed signal from
the transmission output shaft rotational speed or
transfer output shaft rotational speed. The sensor has
the following circuits.
• Ignition voltage feed circuit
• Low reference circuit
• VSS signal circuit
The VSS uses a hall effect element. It interacts with the
magnetic field created by the rotating magnet and
outputs square wave pulse signal. The ECM calculates
the vehicle speed by the VSS. If the 2WD fitted with
Jatco automatic transmission, VSS signals are sent
from the TCM. If the ECM detects VSS signals are
sharply changed, this DTC will set.
Condition for Running the DTC • The ignition voltage is more than 9 volts.
• The ignition switch is ON.
Condition for Setting the DTC • The ECM detects that the VSS signal are changed larger than a predetermined vehicle speed within a
very short calibrated time. 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 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.
• Electromagnetic interference in the VSS circuits may set this DTC.
Notice: • If this DTC set, the Vehicle Speed parameter on the scan tool will display 3 km/h (2 MPH).
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0501
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 all of the circuits going to the vehicle
speed sensor (VSS) for the following
conditions:
• Routed too closely to fuel injection wiring or components
• Routed too closely to after-market add- on electrical equipment
• Routed too closely to solenoids, relays, and motors
2. If you find incorrect routing, correct the harness routing.
Did you find and correct the condition? —
Go to Step 8 Go to Step 3
3 1. Inspect for an intermittent, for poor
connections and corrosion at the Meter (10A)
fuse.
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 8 Go to Step 4
4 1. Inspect for an intermittent, a poor connection
and corrosion at the ground terminal (E-10).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 8 Go to Step 5

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ISUZU KB P190 2007