2007 ISUZU KB P190 Circuit

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-189
DTC P0568 (Flash Code 518)
Circuit Description
The cruise control keeps the vehicle speed at a driver's
set speed. When the cruise main switch is turned ON,
signal is provided to the ECM and the cruise main
indicator lamp on the switch or the instrument panel
cluster will light up. When the cruise set/ coast switch is
turned ON, the switch signal is provided to the ECM
and the vehicle speed is set or vehicle speed is
decreased. If the ECM detects the cruise set/ coast
switch signal repeats ON/ OFF or continuously ON, this
DTC will set.
Condition for Running the DTC • The ignition switch is ON.
• The engine is running.
Condition for Setting the DTC
Either of following condition is met: • The ECM detects that the cruise set/ coast switch signal is repeated ON/ OFF continuously within a
very short calibrated time.
• The ECM detects that the cruise set/ coast switch signal is stuck at the ON position (high voltage) for
longer than 120 seconds. Action Taken When the DTC Sets
• The ECM will not illuminate the MIL or SVS lamp. Refer to DTC Type Definitions for Action Taken
When the DTC Sets - Type D.
• The ECM inhibits cruise control.
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the DTC - Type D.
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
Notice: • This DTC will set if the cruise set/ coast switch continues being pushed for longer than 120
seconds.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0568
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 ON the ignition, with the engine OFF.
3. Observe the Cruise Set Switch parameter with a scan tool.
Does the scan tool indicate ON when the switch is
pushed and OFF when the switch is released? —
Go to Diagnostic Aids Go to Step 3
3 1. Turn OFF the ignition.
2. Disconnect the combination switch harness connector (B-59). (Remove the switch from
the IP bezel as necessary)
3. Turn ON the ignition, with the engine OFF.
Does the Cruise Set Switch parameter indicate
OFF? —
Go to Step 5 Go to Step 4
4 1. Test the signal circuit between the ECM (pin
30 of C-58) and the combination switch (pin
12 of B-59) 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 7 Go to Step 6
5 Repair or replace the combination switch.
Did you complete the repair or replacement? —
Go to Step 7
—

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-191
DTC P0571 (Flash Code 26)
Circuit Description
The brake switch is installed on the brake pedal
bracket. The brake switch 1 is a normally open type
switch and the brake switch 2 is a normally closed type
switch. When the brake pedal is pressed, the brake
switch 1 signal is provided to the ECM and the
stoplights are turned ON. Then, the brake switch 2
signal to the ECM is stopped (low voltage). If the ECM
detects the brake switch signals out of correlation, this
DTC will set.
Condition for Running the DTC • The ignition switch is ON.
Condition for Setting the DTC • The ECM detects a brake switch 1 (normally open type switch) signal and brake switch 2 (normally
closed type switch) signal correlation error for
longer than 10 seconds over 33 times since
ignition switch is ON. Action Taken When the DTC Sets
• The ECM will not illuminate the MIL or SVS lamp. Refer to DTC Type Definitions for Action Taken
When the DTC Sets - Type D.
• The ECM inhibits cruise control.
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the DTC - Type D.
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
• Misadjusted brake switch will cause this DTC to set.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0571
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 ON the ignition, with the engine OFF.
3. Observe the Brake Switch 1 parameter with a scan tool while fully depressing and releasing
the brake pedal.
Does the scan tool indicate Applied when the brake
pedal is applied and Released when the brake
pedal is released? —
Go to Step 8 Go to Step 3
3 1. Check to ensure the brake switch is adjusted
correctly. The plunger should be all the way in
when the pedal is released, yet should not
impede with the brake pedal full upward travel.
2. Adjust the brake switch as necessary.
Did you find and correct the condition? —
Go to Step 18 Go to Step 4
4 1. Turn OFF the ignition.
2. Disconnect the brake switch harness connector.
3. Connect a test lamp between the battery voltage feed circuit of the brake switch 1
harness (pin 1 of C-44) and a known good
ground.
Does the test lamp illuminate? —
Go to Step 5 Go to Step 6

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ISUZU KB P190 2007

6E-192 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
51. Turn ON the ignition, with the engine OFF.
2. Observe the Brake Switch 1 parameter with a scan tool while momentarily jumping 3-amp
fused jumper wire across the brake switch
harness connector between pins 1 and 2 of
the C-44.
Does the scan tool indicate Applied when the circuit
is jumpered and Released when the circuit is not
jumpered? —
Go to Step 14 Go to Step 7
6 Repair the open circuit or high resistance between
the Stop Light (15A) fuse and the brake switch (pin
1 of C-44). Check the Stop Light (15A) fuse first.
Did you complete the repair? —
Go to Step 18
—
71. Test the signal circuit between the ECM (pin
21 of C-58) and the brake switch (pin 2 of C-
44) for the following conditions:
• An open 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 18 Go to Step 15
8 Observe the Brake Switch 2 parameter with a scan
tool while fully depressing and releasing the brake
pedal.
Does the scan tool indicate Applied when the brake
pedal is applied and Released when the brake
pedal is released? —
Go to Diagnostic Aids Go to Step 9
9 1. Check to ensure the brake switch is adjusted
correctly. The plunger should be all the way in
when the pedal is released, yet should not
impede with the brake pedal full upward travel.
2. Adjust the brake switch as necessary.
Did you find and correct the condition? —
Go to Step 18 Go to Step 10
10 1. Turn OFF the ignition.
2. Disconnect the brake switch harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Connect a test lamp between the ignition voltage feed circuit of the brake switch 2
harness (pin 4 of C-44) and a known good
ground.
Does the test lamp illuminate? —
Go to Step 11 Go to Step 12
11 Observe the Brake Switch 2 parameter with a scan
tool while momentarily jumping 3-amp fused
jumper wire across the brake switch harness
connector between pins 3 and 4 of the C-44.
Does the scan tool indicate Released when the
circuit is jumpered and Applied when the circuit is
not jumpered? —
Go to Step 14 Go to Step 13
12 Repair the open circuit or high resistance between
the Engine (10A) fuse and the brake switch (pin 4
of C-44). Check the Engine (10A) fuse first.
Did you complete the repair? —
Go to Step 18
—
Step Action Value(s)Yes No

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-193
131. Test the signal circuit between the ECM (pin 1
of C-58) and the brake switch (pin 3 of C-44)
for the following conditions:
• An open 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 18 Go to Step 15
14 1. Inspect for an intermittent and for poor
connections at the harness connector of the
brake switch (pins 1, 2, 3 and 4 of C-44).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 18 Go to Step 16
15 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 1 and 21 of C-58).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 18 Go to Step 17
16 Replace brake switch. Refer to Brake Switch
Replacement.
Did you complete the replacement? —
Go to Step 18
—
17Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 18
—
181. 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. Turn ON the ignition, with the engine OFF.
5. Observe the Brake Switch 1 and Brake Switch 2 parameter with a scan tool while fully
depressing and releasing the brake pedal.
Does the scan tool indicate Applied when the brake
pedal is applied and Released when the brake
pedal is released on each parameter? —
Go to Step 19 Go to Step 2
19 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-195
DTC P0602 (Flash Code 154)
Circuit Description
The electrically erasable & programmable read only
memory (EEPROM) memorizes fuel injector ID code
information. If the ECM detects fuel injector ID codes
are not programmed into the ECM or an error in the
programmed fuel injector ID codes, this DTC will set.
Condition for Running the DTC • The ignition switch is ON.
Condition for Setting the DTC
Either of following condition is met: • The ECM detects that the fuel injector ID code is not programmed.
• The ECM detects an error in the programmed fuel injector ID code.
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 cruise control.
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)
Notice: • Clear the DTC with a scan tool after programming the fuel injector ID code.
Circuit/ System Testing DTC P0602
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. Ensure that all tool connections are secure.
2. Ensure that programming equipment is operating correctly.
3. Install a scan tool.
4. Turn OFF the ignition for 30 seconds.
5. Turn ON the ignition, with the engine OFF.
6. Monitor the DTC Information with a scan tool.
Does the DTC fail this ignition? —
Go to Step 3 Go to Step 5
3 1. Verify the correct fuel injector ID codes are
entered into the ECM with a scan tool. Refer
to ECM Replacement. If the fuel injector ID
codes are correctly entered, clear the DTC
with a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Turn ON the ignition, with the engine OFF.
Does the DTC fail this ignition? —
Go to Step 4 Go to Step 5
4 Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 5
—

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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

6E-198 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0615 (Flash Code 19)
Circuit Description
The ECM controls the starter cut relay, which de-
energizes the starter relay based on engine speed
inputs or immobilizer command signal. The starter cut
relay uses normally close type relay. During engine
stopping, the starter cut relay is closed to allow
grounding the starter relay. Once engine run, the ECM
energizes the starter cut relay to open the starter relay
circuit and starter motor is disengaged even the ignition
is positioned at START. If the ECM detects an improper
voltage on the starter cut relay control circuit, this DTC
will set.
Condition for Running the DTC • The ignition switch is ON.
Condition for Setting the DTC
Either of following condition is met: • The ECM detects a short to ground circuit condition on the starter cut relay control circuit for
longer than 3 seconds when the relay is
commanded OFF. • The ECM detects a short to voltage circuit
condition on the starter cut relay control circuit for
longer than 3 seconds when the relay is
commanded ON.
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 -
Typ e C.
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the SVS Lamp/ DTC - Type C.
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
Notice: • If the starter cut relay control circuit is short to ground, engine does not crank.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0615
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. DO NOT start the engine.
4. Monitor the DTC Information with a scan tool.
Does the DTC fail this ignition? —
Go to Step 4 Go to Step 3
3 1. Start the engine.
2. Monitor the DTC Information with a scan tool.
Does the DTC fail this ignition? —
Go to Step 6 Go to Diagnostic
Aids
4 1. Turn OFF the ignition.
2. Replace the starter cut relay with the head light dimmer relay or replace with a known
good relay.
3. Turn ON the ignition, with the engine OFF. DO NOT start the engine.
4. Monitor the DTC Information with a scan tool.
Does the DTC fail this ignition? —
Go to Step 5 Go to Step 7

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ISUZU KB P190 2007