Circuit ISUZU KB P190 2007 Workshop Repair Manual

6E-164 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
51. Test the circuits between the ECM (pins 62
and 63 of E-90) and the EGR valve (pins 4
and 6 of E-71) for a short circuit each other.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 12 Go to Step 8
6 1. Test the circuits (which ever voltage reading
did not read within the specified value at Step
3) between the ECM (pins 62 and 63 of E-90)
and the EGR valve (pins 4 and 6 of E-71) for
the following conditions:
• An open circuit
• A short to ground
• A short to the position sensor low reference circuit
• High resistance
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 12 Go to Step 9
7 1. Test the circuits (which ever voltage reading
did not read within the specified value at Step
3) between the ECM (pins 62 and 63 of E-90)
and the EGR valve (pins 4 and 6 of E-71) 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 12 Go to Step 11
8 1. Inspect for an intermittent and for poor
connections at the harness connector of the
EGR valve (pins 4 and 6 of E-71).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 12 Go to Step 10
9 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 62 and 63 of E-90).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 12 Go to Step 9
10 Replace the EGR valve. Refer to EGR Valve
Replacement.
Did you complete the replacement? —
Go to Step 10
—
11Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 12
—
Step Action Value(s)Yes No

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ISUZU KB P190 2007

6E-166 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0404 (Flash Code 45)
Circuit Description
The ECM controls the EGR valve opening based on the
engine running condition and by controlling the EGR
solenoid. The EGR valve position is detected by the
position sensor, and relayed to the ECM. If the ECM
detects a variance between the actual EGR valve
position and desired EGR valve position for a
calibrated amount of time while the EGR valve is
commanded ON, this DTC will set.
Condition for Running the DTC • DTCs P0112, P0113, P0116, P0117, P0118, P0405, P0406, P0652, P0653, P2227, P2228 and
P2229 are not set.
• The battery voltage is between 10 to 16 volts.
• The ignition switch is ON.
• The engine coolant temperature is between 20 to 11 0 °C (68 to 230 °F).
• The intake air temperature is between 0 to 110 °C
(32 to 230 °F).
• The barometric pressure is between 60 to 120 kPa (8.7 to 17.4 psi).
• The EGR control is commanded ON. Condition for Setting the DTC
• The ECM detects that the actual EGR position is more than 10% below the desired position for 4
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 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.
• A sticking or intermittently sticking EGR valve may set this DTC.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0404
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 P0403, P0405 or P0406 also set? —
Go to Applicable DTC Go to Step 3
3 1. Perform the EGR Solenoid Control with a scan
tool several times.
2. Command the Desired EGR Position Increase and Decrease while observing the EGR
Position.
Does the EGR Position parameter follow within the
specified value quick enough (compare with a
similar unit if available)?
± 5%
Go to Diagnostic Aids Go to Step 4

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-167
41. Remove the EGR valve assembly from the
engine.
2. Inspect the EGR valve for the following conditions:
• Restricted EGR valve by foreign materials
• Excessive deposits at valve
• Bent valve shaft
3. Repair or replace as necessary.
Did you find and correct the condition? —
Go to Step 7 Go to Step 5
5 1. Turn OFF the ignition.
2. Disconnect the EGR valve harness connector.
3. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the EGR valve (pins 1, 2, 3, 4
and 6 of E-71).
4. Disconnect the ECM harness connector.
5. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the ECM (pins 30, 31, 32, 62 and
63 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 7 Go to Step 6
6 Replace the EGR valve. Refer to EGR Valve
Replacement.
Did you complete the replacement? —
Go to Step 7
—
71. 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 8
8 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-168 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0405 or P0406 (Flash Code 44)
Circuit Description
The exhaust gas recirculation (EGR) position sensor is
installed on the EGR valve body together with the
control solenoid. The EGR position sensor changes
output voltage according to EGR valve position. The
sensor has the following circuits.
• 5 volts reference circuit
• Low reference circuit
• EGR position sensor signal circuit
The EGR position sensor provides a signal to the ECM
on the signal circuit, which is relative to the position
changes of the EGR valve. If the ECM detects an
excessively low or high signal voltage, DTC P0405 or
P0406 will set.
Condition for Running the DTC • DTCs P0652 and P0653 are not set.
• The battery voltage is more than 9 volts.
• The ignition switch is ON.
Condition for Setting the DTC • The ECM detects that the EGR position sensor signal voltage is less than 0.2 volts for 3 seconds.
(DTC P0405)
• The ECM detects that the EGR position sensor signal voltage is more than 4.6 volts for 3 seconds.
(DTC P0406) Action Taken When the DTC Sets
• The ECM illuminates the MIL on the second consecutive driving cycle when the diagnostic runs
and fails. Refer to DTC Type Definitions for Action
Taken When the DTC Sets - Type B. (Euro 4
Specification)
• 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.
(Except Euro 4 Specification)
• 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 B. (Euro 4
Specification)
• Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A. (Except Euro 4
Specification)
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0405
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 P0652 also set? —
Go to DTC P0652 Go to Step 3
3 Observe the EGR Position Sensor parameter with
a scan tool.
Is EGR Position Sensor parameter less than the
specified value? 0.2 volts
Go to Step 4 Go to Diagnostic
Aids
4 1. Turn OFF the ignition.
2. Disconnect the EGR valve harness connector.
3. Connect a DMM between the 5 volts reference circuit (pin 1 of E-71) and a known good
ground.
4. Turn ON the ignition, with the engine OFF.
Is the DMM voltage more than the specified value? 4.7 volts
Go to Step 5 Go to Step 6

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-169
5Connect a 3-amp fused jumper wire between the 5
volts reference circuit and the signal circuit (pins 1
and 3 of E-71).
Is the EGR Position Sensor parameter more than
the specified value? 4.7 volts
Go to Step 8 Go to Step 7
6 1. Test the 5 volts reference circuit between the
ECM (pin 31 of E-90) and the EGR valve (pin
1 of E-71) for an open circuit or high
resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 12 Go to Step 9
7 1. Test the signal circuit between the ECM (pin
32 of E-90) and the EGR valve (pin 3 for E-71)
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 12 Go to Step 9
8 1. Inspect for an intermittent and for poor
connections at the harness connector of the
EGR valve (pins 1 and 3 of E-71).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 12 Go to Step 10
9 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 31 and 32 of E-90).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 12 Go to Step 11
10 Replace the EGR valve. Refer to EGR Valve
Replacement.
Did you complete the replacement? —
Go to Step 12
—
11Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 12
—
121. 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 13
Step
Action Value(s)Yes No

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6E-170 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Circuit/ System Testing DTC P0406
13Observe 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 EGR Position Sensor parameter with a scan tool.
Is the EGR Position Sensor parameter more than
the specified valve? 4.6 volts
Go to Step 3 Go to Diagnostic
Aids
3 Monitor the DTC Information with a scan tool.
Is DTC P0653 also set? —
Go to Step 4 Go to Step 5
4 1. Turn OFF the ignition.
2. Disconnect the EGR valve harness connector.
3. Turn ON the ignition, with the engine OFF.
Is the EGR Position Sensor parameter less than
the specified value? 0.1 volts
Go to DTC P0653 Go to Step 7
5 1. Turn OFF the ignition.
2. Disconnect the EGR valve harness connector.
3. Turn ON the ignition, with the engine OFF.
Is the EGR Position Sensor parameter less than
the specified value? 0.1 volts
Go to Step 6 Go to Step 7
6 Connect a test lamp between the low reference
circuit (pin 2 of E-71) and battery voltage.
Does the test lamp illuminate? —
Go to Step 9 Go to Step 8
7 Important:
The EGR position sensor may be
damaged if the sensor signal circuit is shorted to a
voltage source.
1. Test the signal circuit between the ECM (pin 32 of E-90) and the EGR valve (pin 3 of E-71)
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 13 Go to Step 12
8 1. Test the low reference circuit between the
ECM (pin 30 of E-90) and the EGR valve (pin
2 of E-71) for an open circuit or high
resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 10

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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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ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-173
51. Turn OFF the ignition.
2. Disconnect the TCM harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Intermittently jump the signal circuit (pin 10 of C-94) with a test lamp that is connected to a
known good ground while observing the
Vehicle Speed parameter with a scan tool.
Does the scan tool indicate any vehicle speed
when the circuit is intermittently pulled to ground? —
Go to Step 7 Go to Step 6
6 1. Test the signal circuit between the ECM (62 of
C-58) and the TCM (10 of C-94) 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. Turn OFF the ignition.
2. Inspect for an intermittent and for a poor connection at the harness connector of the
TCM (pin 10 of C-94).
3. 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. Inspect for an intermittent and for a poor connection at the harness connector of the
ECM (pin 62 of C-58).
3. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 10
9 Important:
Replacement TCM must be
programmed.
Replace the TCM. Refer to TCM 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
—
111. Reconnect all previously disconnected
harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Drive the vehicle while observing the Vehicle Speed parameter with a scan tool.
Does the scan tool indicate correct vehicle speed? —
Go to Step 12 Go to Step 3
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

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ISUZU KB P190 2007

6E-174 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Circuit/ System Testing DTC P0500 (except 2WD fitted with Jatco A/T)
StepAction 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 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 4
4 1. Turn OFF the ignition.
2. Disconnect the vehicle speed sensor (VSS) harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Connect a test lamp between the ignition voltage feed circuit (pin 1 of E-44) and a
known good ground.
Does the test lamp illuminate? —
Go to Step 5 Go to Step 7
5 Intermittently jump the signal circuit (pin 3 of E-44)
with a test lamp that is connected to a known good
ground while observing the Vehicle Speed
parameter with a scan tool.
Does the scan tool indicate any vehicle speed
when the circuit is intermittently pulled to ground? —
Go to Step 6 Go to Step 9
6 Connect a test lamp between the voltage feed
circuit and the low reference circuit (pins 1 and 2 of
E-44).
Does the test lamp illuminate? —
Go to Step 10 Go to Step 8
7 Repair the open circuit or high resistance between
the Meter (10A) fuse and the VSS (pin 1 of E-44).
Check the Meter (10A) fuse first.
Did you complete the repair? —
Go to Step 15
—
8Repair the open circuit or high resistance on the
low reference circuit between the VSS (pin 2 of E-
44) and ground terminal (E-10). Clean or tighten
ground as necessary.
Did you complete the repair? —
Go to Step 15
—
91. Test the signal circuit between the ECM (pin
62 of C-58) and the VSS (pin 3 of E-44), then
between the instrument panel (IP) cluster (pin
8 of B-23) and the VSS (pin 3 of E-44) for the
following conditions:
• An open circuit
• A short to ground
• A short to the low reference 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 15 Go to Step 11

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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