relay ISUZU KB P190 2007 Workshop Repair Manual

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-139
DTC P0231 or P0232 (Flash Code 69)
Circuit Description
The ECM controls the fuel pump relay which supplies
power to the fuel pump in the fuel tank. The ECM
commands the fuel pump relay ON for a certain length
of time at ignition switch is ON with the engine OFF.
During the engine running it is continuously
commanded ON. If the ECM detects an improper
voltage level on the relay control circuit, DTC P0231 or
P0232 will set.
Condition for Running the DTC • The battery voltage is more than 9 volts.
• The ignition switch is ON.
Condition for Setting the DTC • The ECM detects a low voltage condition on the fuel pump relay control circuit for longer than 3
second when the relay is commanded OFF. (DTC
P0231)
• The ECM detects a high voltage condition on the fuel pump relay control circuit for longer than 3
second when the relay is commanded ON. (DTC
P0232)
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)
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
Notice: • The fuel pump relay is commanded ON for 12 seconds at ignition switch is ON with the engine
OFF.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0231
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 for 20 seconds while observing the DTC Information with a scan
tool.
Does the DTC fail this ignition? —
Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition.
2. Replace the fuel pump relay with the head light relay or replace with a known good relay.
3. Turn ON the ignition for 20 seconds while observing the DTC Information with a scan
tool.
Does the DTC fail this ignition? —
Go to Step 4 Go to Step 7

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ISUZU KB P190 2007

6E-140 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
41. Turn OFF the ignition.
2. Remove the fuel pump relay.
3. Probe the ignition voltage feed circuit of the relay coil side (pin 3 of X-13) with a test lamp
that is connected a known good ground.
4. Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate? —
Go to Step 5 Go to Step 6
5 1. Test the control circuit between the ECM (pin
54 of C-58) and the relay (pin 5 of X-13) for
the following conditions:
• An open circuit
• A short to ground
• High resistance
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 8
6 Repair the open circuit or high resistance between
the ECM main relay (pin 1 of X-12) and the fuel
pump relay (pin 3 of X-13).
Did you complete the repair? —
Go to Step 11
—
71. Remove the fuel pump relay.
2. Inspect for an intermittent and for a poor connection on each relay terminal.
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. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for a poor connection at the harness connector of the
ECM (pin 54 of C-58).
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 fuel pump relay.
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,
relay 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 for 20 seconds while observing the DTC Information with a scan
tool.
Did the DTC fail this ignition? —
Go to Step 3 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

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-141
Circuit/ System Testing DTC P0232
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. Start the engine.
4. Monitor the DTC Information with a scan tool.
Does the DTC fail this ignition? —
Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition.
2. Replace the fuel pump relay with the head light relay or replace with a known good relay.
3. Start the engine.
4. Monitor the DTC Information with a scan tool.
Does the DTC fail? —
Go to Step 4 Go to Step 5
4 1. Test the control circuit between the ECM (pin
54 of C-58) and the relay (pin 5 of X-13) 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 Replace the fuel pump relay.
Did you complete the replacement? —
Go to Step 7
—
6Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 7
—
71. Reconnect all previously disconnected 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 3 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

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-151
DTC P0336 (Flash Code 15)
Circuit Description
The crankshaft position (CKP) sensor is located on the
left-hand of the cylinder block rear and it is behind the
starter motor. The sensor rotor is fixed on the
crankshaft. There are 56 notches spaced 6 ° apart and
a 30 ° section that is open span. This open span portion
allows for the detection of top dead center (TDC). The
ECM monitors both CKP sensor and camshaft position
(CMP) sensor signal pulses to ensure they correlate
with each other. If the ECM receives extra or missing
CKP sensor signal pulse, this DTC will set.
Condition for Running the DTC • DTC P0335 is not set.
• The battery voltage is more than 9 volts.
• The ignition switch is ON.
• The CKP sensor signal pulse is detected.
Condition for Setting the DTC • The ECM detects extra or missing CKP sensor signal pulses during engine rotations. 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 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 CKP sensor circuits may set this DTC.
• An intermittent CKP sensor signal pulse may set this DTC.
• Ensure the sensor is tight and the sensor rotor teeth are not damaged.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0336
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 (Note a slight start delay may be noticed).
4. Monitor the DTC Information with a scan tool.
Is DTC P0335, P0340, P0341, P0698 or P0699
also set? —
Go to Applicable DTC Go to Step 3
3 1. Inspect all of the circuits going to the
crankshaft position (CKP) sensor 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 and relays
2. If you find incorrect routing, correct the harness routing.
Did you find and correct the condition? —
Go to Step 7 Go to Step 4

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ISUZU KB P190 2007

6E-156 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0341 (Flash Code 14)
Circuit Description
The camshaft position (CMP) sensor is installed on the
timing chain sprocket cover at the front of the camshaft
idle gear. The CMP sensor detects total of five
projections per one engine cycle (four projections
arranged equally every 90 ° and one reference
projection on the timing chain sprocket surface). The
ECM monitors both crankshaft position (CKP) sensor
and CMP sensor signal pulses to ensure they correlate
with each other. If the ECM receives extra or missing
CMP sensor signal pulse, this DTC will set.
Condition for Running the DTC • DTCs P0016 and P0340 are not set.
• The battery voltage is more than 9 volts.
• The ignition switch is ON.
• The CMP sensor signal pulse is detected.
Condition for Setting the DTC • The ECM detects extra or missing CMP sensor signal pulses during engine rotations.
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 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)
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
• Electromagnetic interference in the CMP sensor circuits may set this DTC.
• An intermittent CMP sensor signal pulse may set this DTC.
• Ensure the sensor is tight and the timing chain sprocket is not damaged.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0341
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. If the engine does not start, crank over the engine for 10 seconds.
4. Monitor the DTC Information with a scan tool.
Is DTC P0340, P0652 or P0653 also set? —
Go to Applicable DTC Go to Step 3
3 1. Inspect all of the circuits going to the camshaft
position (CMP) sensor 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 and relays
2. If you find incorrect routing, correct the harness routing.
Did you find and correct the condition? —
Go to Step 7 Go to Step 4

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ISUZU KB P190 2007

6E-158 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0380 (Flash Code 66)
Circuit Description
The ECM controls the glow relay which supplies power
to the glow plugs based on engine coolant
temperature. In the after glow phase, the glow indicator
light is not illuminated but glow plugs remain active for
a certain period. If the ECM detects an open circuit or
short circuit on the relay control circuit, this DTC will
set.
Condition for Running the DTC • The battery voltage is more than 9 volts.
• The ignition voltage is more than 9 volts.
• The ignition switch is ON.
Condition for Setting the DTC
Either of following condition is met: • The ECM detects a low voltage condition on the glow relay control circuit for longer than 3 second
when the relay is commanded OFF.
• The ECM detects a high voltage condition on the glow relay control circuit for longer than 3 second
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 -
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)
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)
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
Test Description
The numbers below refers to the step number on the
Circuit/ System Testing.
2. Listen for an audible click when the glow relay
operates. Command both the ON and OFF states.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0380
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. Perform the Glow Relay Control with a scan tool.
3. Command the relay ON and OFF.
Does the glow relay click with each command? —
Go to Step 3 Go to Step 4
3 1. Turn OFF the ignition for 30 seconds.
2. Disconnect the engine coolant temperature (ECT) sensor harness connector in order to
gain glow ON time long enough.
3. Turn ON the ignition for 30 seconds while observing the DTC Information with a scan
tool.
Does the DTC P0380 fail this ignition? —
Go to Step 11 Go to Diagnostic
Aids

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-159
41. Turn OFF the ignition.
2. Replace the glow relay with the starter relay or replace with a known good relay.
3. Perform the Glow Relay Control with a scan tool.
4. Command the relay ON and OFF.
Does the glow relay click with each command? —
Go to Step 8 Go to Step 5
5 1. Turn OFF the ignition.
2. Remove the glow relay.
3. Turn ON the ignition, with the engine OFF.
4. Probe the ignition voltage feed circuit of the relay coil side (pin 2 of X-5) with a test lamp
that is connected to a known good ground.
Does the test lamp illuminate? —
Go to Step 6 Go to Step 7
6 1. Test the control circuit between the ECM (pin
37 of C-58) and the relay (pin 3 of X-5) for the
following conditions:
• An open circuit
• A short to ground
• 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 9
7 Repair the open circuit or high resistance between
the Engine (10A) fuse and the glow relay coil side
(pin 2 of X-5). Check the Engine (10A) fuse first.
Did you complete the repair? —
Go to Step 12
—
81. Remove the glow relay.
2. Inspect for an intermittent and for a poor connection on each relay terminal.
3. 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 a poor connection at the harness connector of the
ECM (pin 37 of C-58).
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 glow relay.
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
—
Step Action Value(s)Yes No

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ISUZU KB P190 2007

6E-160 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
121. 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. Disconnect the ECT sensor harness connector in order to gain glow ON time long
enough.
5. Turn ON the ignition for 30 seconds while observing the DTC Information with a scan
tool.
Did the DTC P0380 fail this ignition? —
Go to Step 2 Go to Step 13
13 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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ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-161
DTC P0401 (Flash Code 93)
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. When the
proper enabling conditions are met, the ECM will open
the EGR valve while monitoring the mass air flow
(MAF) signal. An expected MAF difference should be
detected between the closed and open positions. If the
ECM detects the MAF difference less than expected,
this DTC will set. This DTC will only run once per
ignition cycle within the enabling conditions.
Condition for Running the DTC • DTCs P0101, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0122, P0123, P0403,
P0404, P0405, P0406, P0500, P0501, P0652,
P0653, P0698, P0699, P2100, P2101, P2102,
P2103, P2227, P2228 and P2229 are not set.
• The battery voltage is between 10 to 16 volts.
• The ignition switch is ON. Condition for Setting the DTC
• The ECM detects that the MAF amount is not within the calculated range during the EGR flow
test. This indicates insufficient amount of EGR
flow.
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 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 the EGR valve may set this DTC.
Circuit/ System Testing DTC P0401
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 and warm up as necessary (allow engine coolant temperature to reach at
least 60 °C [140 °F]).
4. Perform the EGR Solenoid Control with a scan tool.
5. Command the Desired EGR Position Increase or Decrease while observing the Mass Air
Flow (MAF) Sensor parameter with a scan
tool.
Does the MAF Sensor parameter decrease by at
least 0.5 volts when the Desired EGR Position is
commanded from 0 to 90%? —
Go to Diagnostic Aids Go to Step 3

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-163
DTC P0403 (Flash Code 37)
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 an open circuit or short circuit on the solenoid
circuits, this DTC will set.
Condition for Running the DTC • The battery voltage is more than 9 volts.
• The ignition switch is ON.
Condition for Setting the DTC
Either of following condition is met: • The ECM detects an open circuit on the EGR solenoid circuits.
• The ECM detects a short to ground on the EGR solenoid circuits.
• The ECM detects a short to voltage circuit on the EGR solenoid circuits. 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.
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 P0403
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 with a scan tool.
Does the DTC fail this ignition? —
Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition.
2. Disconnect the EGR valve harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Connect a DMM between the drive voltage circuit (pin 4 of E-71) and a known good
ground.
5. Connect a DMM between the low side circuit (pin 6 of E-71) and a known good ground.
Are both voltage readings within the specified
value? 1.4 - 1.8 volts
Go to Step 5 Go to Step 4
4 Is the DMM voltage more than the specified value
at Step 3? —
Go to Step 7 Go to Step 6

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ISUZU KB P190 2007