2007 ISUZU KB P190 EGR

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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ISUZU KB P190 2007

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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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-171
91. Inspect for an intermittent and for a poor
connection at the harness connector of the
EGR valve (pin 2 of E-71).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 11
10 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 30 of E-90).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 12
11 Replace the EGR valve. Refer to EGR Valve
Replacement.
Did you complete the replacement? —
Go to Step 13
—
12Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 13
—
131. 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 14
14 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-194 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0601 (Flash Code 53)
Circuit Description
This diagnostic applies to internal microprocessor
integrity conditions within the ECM.
Condition for Setting the DTC • The ECM detects that the calculated checksum does not agree with the ECM internal registered
checksum.
Action Taken When the DTC Sets • The ECM illuminates the SVS lamp when the diagnostic runs and fails. Refer to DTC Type
Definitions for Action Taken When the DTC Sets -
Type C. (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 limits fuel injection quantity.
• The ECM inhibits pilot injection.
• The ECM inhibits cruise control.
• The ECM stops engine running when the vehicle speed is lower than 5 km/h (3 MPH) for 5 seconds.
The engine will run after the key is cycled when the
ignition has been tuned OFF for longer than 10
seconds.
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the SVS Lamp/ DTC - Type C. (Euro 4
Specification)
• Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A. (Except Euro 4
Specification)
Circuit/ System Testing DTC P0601
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 Step 4
3 Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 4
—
41. Clear the DTCs with a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. 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 5
5 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-197
DTC P0604 or P0606 (Flash Code 153 or 51)
Circuit Description
This diagnostic applies to internal microprocessor
integrity conditions within the ECM.
Condition for Setting the DTC • The ECM detects a malfunction in its internal random access memory (RAM). (DTC P0604)
• The ECM detects a malfunction in its internal main central processing unit (CPU) or sub integrated
circuit (IC). (DTC P0606)
Action Taken When the DTC Sets • The ECM illuminates the SVS lamp when the diagnostic runs and fails. Refer to DTC Type
Definitions for Action Taken When the DTC Sets -
Type C. (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 limits fuel injection quantity. (DTC
P0604)
• The ECM inhibits pilot injection. (DTC P0604)
• The ECM inhibits cruise control. (DTC P0604)
• The ECM stops engine running when the vehicle speed is lower than 5 km/h (3 MPH) for 5 seconds.
The engine will run after the key is cycled when the
ignition has been tuned OFF for longer than 10
seconds. (DTC P0604)
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the SVS Lamp/ DTC - Type C. (Euro 4
Specification)
• Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A. (Except Euro 4
Specification)
Circuit/ System Testing DTC P0604 or P0606
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 Step 4
3 Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 4
—
41. Clear the DTCs with a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. 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 5
5 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK

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ISUZU KB P190 2007