2007 ISUZU KB P190 ECO mode

6E-206 Engine Control System (4JH1)
DTC P1173 (Symptom Code 7, A) (Flash Code 22)
Circuit Description
The fuel temperature (FT) sensor is internal to the fuel
injection pump control unit (PCU). It detects fuel
temperature in the fuel injection pump. If the PCU
detects an excessively high or low fuel temperature, this
DTC will set.
Condition for Running the DTC
• The ignition switch is ON.
Condition for Setting the DTC • The ECM detects an excessive high FT for longe
r
than 30 seconds. (Symptom Code 7)
• The ECM detects an excessive low FT for longe
r
than 30 seconds. (Symptom Code A)
Action Taken When the DTC Sets • The ECM does not illuminate the malfunction
indicator lamp (MIL) when the diagnostic runs and
fails.
• The PCU limits fuel injection quantity. (Symptom
Code 7)
Condition for Clearing the DTC
• A history DTC clears after 40 consecutive driving
cycles without a fault. Or clear with the scan tool.
Diagnostic Aids
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
Notice:
• FT sensor is internal to the PCU and it is part o
f
the fuel injection pump assembly.

DTC P1173 (Symptom Code 7, A) (Flash Code 22)


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 the scan tool. 2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the Diagnostic Trouble Code (DTC) Information with the scan tool.
Does the DTC fail this ignition? 

Go to Step 3 Go to Step 4
3 Important: The fuel injection pump must be timed to
the engine.
Replace the fuel injection pump. Refer to Fuel
Injection Pump Replacement in engine mechanical
section. (Fuel temperature [FT] sensor is internal to
the fuel injection pump control unit [PCU] and it is
part of the fuel injection pump assembly.)
Did you complete the replacement? 

Go to Step 4 
4 1. Clear the DTCs with the scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the DTC Information with the scan tool.
Did the DTC fail this ignition? 

Go to Step 3 Go to Step 5
5 Observe the DTC Information with the scan tool. Are there any DTCs that you have not diagnosed?  Go to Diagnostic
Trouble Code (DTC) List System OK



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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-207
DTC P1335 (Symptom Code A) (Flash Code 43)
Circuit Description
The crankshaft position (CKP) sensor is located on top
of the flywheel housing. There are 4 slits spaced 90 °
on the flywheel circumference. The CKP sensor is a
magnetic coil type sensor, which generates an AC
signal voltage based on the crankshaft rotational speed.
The engine control module (ECM) monitors both the
CKP sensor and injection pump camshaft position
(CMP) sensor signals to ensure they correlate with each
other. If the fuel injection pump control unit (PCU)
receives faulty CKP sensor signal pulses, this DTC will
set.
Condition for Running the DTC
• The ignition switch is ON.
Condition for Setting the DTC • The PCU detects CKP sensor signal from the
ECM is faulty.
Action Taken When the DTC Sets • The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
• The ECM limits fuel injection quantity.
Condition for Clearing the MIL/DTC
• The ECM turns OFF the MIL when the diagnostic
runs and does not fail.
• A history DTC clears after 40 consecutive driving
cycles without a fault. Or clear with the scan tool.
Diagnostic Aids
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
Notice: • PCU is part of the fuel injection pump assembly.

DTC P1335 (Symptom Code A) (Flash Code 43)
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or Engine Control Module (ECM)
Connector End Views

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 the 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 Diagnostic Trouble Code (DTC) Information with the scan tool.
Is DTC P0335 (Symptom Code B or D) set? 

Go to Applicable DTC Go to Step 3
3 1. Turn OFF the ignition. 2. Disconnect the engine control module (ECM) C-57 harness connector. Keep the C-56 harness
connector with connected.
3. Connect a DMM between the crankshaft position (CKP) sensor signal output circuit (pin 91 of C-57
connector) and a known good ground.
4. Turn ON the ignition, with the engine OFF.
Does the DMM voltage more than the specified
value? 10 volts
Go to Step 5 Go to Step 4
4 1. Test the CKP sensor signal output circuit between the ECM (pin 91 of C-57 connector) and
the fuel injection pump (pin 8 of E-6 connector)
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 10 Go to Step 6

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ISUZU KB P190 2007

6E-208 Engine Control System (4JH1)
Step Action Value(s) Yes No
5 1. Test the CKP sensor signal output circuit
between the ECM (pin 91 of C-57 connector) and
the fuel injection pump control unit (PCU) (pin 8
of E-6 connector) for a short to battery or ignition
voltage.
Notice:
Perform this by connecting a test lamp between the
ECM harness connector (pin 91 of C-57 connector)
and a known good ground. If the test lamp
illuminate, circuit is short to battery or ignition
voltage.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 10 Go to Step 7
6 1. Turn OFF the ignition. 2. Disconnect the PCU harness connector.
3. Inspect for an intermittent and for a poor connection on the CKP sensor signal circuit at
the harness connector of the PCU (pin 8 of E-6
connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 10 Go to Step 8
7 1. Turn OFF the ignition. 2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for a poor connection on the CKP sensor signal output
circuit at the harness connector of the ECM (pin
92 of C-57 connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 10 Go to Step 9
8 Important: The fuel injection pump must be timed to
the engine.
Replace the fuel injection pump. Refer to Fuel
Injection Pump Replacement in engine mechanical
section.
Did you complete the replacement? 

Go to Step 10
9 Important: Replacement ECM must be
programmed.
Replace the ECM. Refer to Engine Control Module
(ECM) Replacement in this section.
Did you complete the replacement? 

Go to Step 10 
10 1. Reconnect all previously disconnected harness
connector(s).
2. Clear the DTCs with the scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Monitor the DTC Information with the scan tool.
Did the DTC fail this ignition? 

Go to Step 2 Go to Step 11
11 Observe the DTC Information with the scan tool. Are there any DTCs that you have not diagnosed?  Go to Diagnostic
Trouble Code (DTC) List System OK



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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-209
DTC P1345 (Symptom Code A) (Flash Code 41)
Circuit Description
The engine control module (ECM) calculates the
desired fuel injection quantity and timing using data sent
from various sensors. These desired data are sent to
the fuel injection pump control unit (PCU) via a
controller area network (CAN) communication bus. The
PCU also receives signals from the internal inputs:
pump camshaft position (CMP) sensor that is located
inside the fuel injection pump to determine the cam ring
rotation angle and the fuel injection pump speed. The
fuel temperature (FT) sensor is internal the PCU. These
values are used to compare the desired values sent
from the ECM then PCU determines the injection time
r
piston position and fuel injection quantity, and actuates
timing control valve (TCV) & fuel injection solenoid
valve based on control maps in the PCU. The PCU also
compares the engine speed signal sent from the ECM
and the fuel injection pump speed. If the PCU received
faulty fuel injection pump CMP sensor signal, this DTC
will set.
Condition for Setting the DTC • The PCU received faulty fuel injection pump CMP
sensor signal for 1 second.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
• The ECM limits fuel injection quantity.
Condition for Clearing the MIL/DTC • The ECM turns OFF the MIL when the diagnostic
runs and does not fail.
• A history DTC clears after 40 consecutive driving
cycles without a fault. Or clear with the scan tool.
Diagnostic Aids
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
Notice:
• Fuel injection pump CMP sensor is internal to the
fuel injection pump assembly.
• PCU is part of the fuel injection pump assembly.

DTC P1345 (Symptom Code A) (Flash Code 41)


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 the scan tool. 2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the Diagnostic Trouble Code (DTC) Information with the scan tool.
Does the DTC fail this ignition? 

Go to Step 3 Go to Step 4
3 Important: The fuel injection pump must be timed to
the engine.
Replace the fuel injection pump. Refer to Fuel
Injection Pump Replacement in engine mechanical
section.
Did you complete the replacement? 

Go to Step 4 
4 1. Clear the DTCs with the scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the DTC Information with the scan tool.
Does the DTC fail this ignition? 

Go to Step 3 Go to Step 5
5 Observe the DTC Information with the scan tool. Are there any DTCs that you have not diagnosed?  Go to Diagnostic
Trouble Code (DTC) List System OK


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ISUZU KB P190 2007

6E-210 Engine Control System (4JH1)
DTC P1520 (Symptom Code A) (Flash Code 47)
Circuit Description
(Manual Transmission)
The neutral switch is installed on the transmission gea
r
control box. W hen the gear position is neutral, the
switch is closed and the switch signal is provided to the
engine control module (ECM). If the ECM detects the
neutral switch signal is not changed from neutral during
the predetermined engine speed and vehicle speed
range, this DTC will set.
(Automatic Transmission)
The inhibitor switch is installed to the transmission case.
W hen the selector position is P or N range, the switch is
closed and the switch signal is provided to the Emir the
ECM detects the neutral switch signal is not changed
from P or N during the predetermined engine speed and
vehicle speed range, this DTC will set.
Condition for Running the DTC • The ignition switch is ON.
• The engine speed is higher than 1500 RPM.
• The vehicle speed is higher than 63 km/h (39
MPH) (M/T) or 78 km/h (49 MPH) (A/T).
• The clutch pedal is released. (M/T).

Condition for Setting the DTC
• The ECM detects that the neutral switch signal is
continuously ON (neutral or P/N range) during
three consecutive driving cycles.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
Condition for Clearing the MIL/DTC
Important: • Following conditions must be met two consecutive
driving cycles. (One driving cycle: Ignition switch
ON > Engine run > Vehicle run > Ignition switch
OFF for 10 seconds)
- The engine speed is higher than 1500 RPM
- The vehicle speed is higher than 63 km/h (39 MPH) (M/T) or 78 km/h (49 MPH) (A/T)
- The clutch pedal is released (M/T)

- Other than neutral or P/N range
- After the above procedure is done, a history
DTC clears after 40 consecutive driving cycles
without a fault. Or clear with the scan tool.
Diagnostic Aids
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.

DTC P1520 (Symptom Code A) (Flash Code 47)
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or Engine Control Module (ECM)
Connector End Views

Chart for M/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 the scan tool. 2. Turn ON the ignition, with the engine OFF.
3. Observe the Neutral Switch parameter with the scan tool while shift to neutral and other
positions.
Does the scan tool indicate ON when the position is
neutral and OFF when other than the neutral? 

Go to Diagnostic Aids Go to Step 3
3 1. Turn OFF the ignition. 2. Disconnect the neutral switch harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Observe the Neutral Switch parameter with the scan tool.
Does the scan tool indicate ON? 

Go to Step 4 Go to Step 5
4 1. Test the neutral switch input signal circuit between the engine control module (ECM) (pin
87 of C-57 connector) and the neutral switch (pin
1 of E-11 connector) 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

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-211
Step Action Value(s) Yes No
5 Replace the neutral switch. Refer to Neutral Switch
Replacement in Transmission Section.
Did you complete the replacement? 

Go to Step 7 
6 Important: Replacement ECM must be
programmed.
Replace the ECM. Refer to Engine Control Module
(ECM) Replacement in this section.
Did you complete the replacement? 

Go to Step 7 
7 1. Reconnect all previously disconnected harness
connector(s).
2. Clear the DTCs with the scan tool.
Important: Following conditions must be met two
consecutive driving cycles before clear with the scan
tool. (One driving cycle: Ignition switch ON > Engine
run > Vehicle run > Ignition switch OFF for 10
seconds) • The engine speed is higher than 1500 RPM
• The vehicle speed is higher than 63 km/h
(39 MPH)
• The clutch pedal is released
• Other than neutral
3. Turn ON the ignition, with the engine OFF.
4. Observe the Neutral Switch parameter with the scan tool while shift to neutral and other
positions.
Does the scan tool indicate ON when the position is
neutral and OFF when other than the neutral? 

Go to Step 8 Go to Step 3
8 Observe the DTC Information with the scan tool. Are there any DTCs that you have not diagnosed?  Go to Diagnostic
Trouble Code (DTC) List System OK

Chart for 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 the scan tool. 2. Turn OFF the ignition for 30 seconds.
3. Turn ON the ignition, with the engine OFF.
4. Select the “JR405E Automatic Transmission” in the system selection menu.
5. Monitor the Read Diagnostic Trouble Code (DTC) Info As Stored By ECU with the scan tool.
Does the transmission control module (TCM) DTC
P0705 set? 

Go to Applicable
DTC in Automatic Transmission Section Go to Step 3
3 1. Install the scan tool. 2. Turn ON the ignition, with the engine OFF.
3. Observe the Neutral Switch parameter with the scan tool while shift to P or N and other
positions.
Does the scan tool indicate ON when the position is
P or N and OFF when other than the P or N? 

Go to Diagnostic Aids Go to Step 4

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ISUZU KB P190 2007

6E-212 Engine Control System (4JH1)
Step Action Value(s) Yes No
4 1. Check to ensure the inhibitor switch is adjusted
correctly.
2. Adjust the inhibitor switch as necessary. Refer to Inhibitor Switch Adjustment in Automatic
Transmission Section.
Did you find and correct the condition? 

Go to Step 7 Go to Step 5
5 1. Test the P & N position switch signal circuit between the engine control module (ECM) (pin
87 of C-57 connector) and the diode (pin 2 of X-
16 connector) 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
6 Important: Replacement ECM must be
programmed.
Replace the ECM. Refer to Engine Control Module
(ECM) Replacement in this section.
Did you complete the replacement? 

Go to Step 7 
7 1. Reconnect all previously disconnected harness
connector(s).
2. Clear the DTCs with the scan tool.
Important: Following conditions must be met two
consecutive driving cycles before clear with the scan
tool. (One driving cycle: Ignition switch ON > Engine
run > Vehicle run > Ignition switch OFF for 10
seconds) • The engine speed is higher than 1500 RPM
• The vehicle speed is higher than 78 km/h
(49 MPH)
• Other than P/N range
3. Turn ON the ignition, with the engine OFF.
4. Observe the Neutral Switch parameter with the scan tool while shift to P or N and other
positions.
Does the scan tool indicate ON when the position is
P or N and OFF when other than the P or N? 

Go to Step 8 Go to Step 2
8 Observe the DTC Information with the scan tool. Are there any DTCs that you have not diagnosed?  Go to Diagnostic
Trouble Code (DTC) List System OK


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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-213
DTC P1520 (Symptom Code B) (Flash Code 47)
Circuit Description
The neutral switch is installed on the transmission gea
r
control box. W hen the gear position is neutral, the
switch is closed and the switch signal is provided to the
engine control module (ECM). If the ECM detects the
neutral switch signal is not changed from other than
neutral during the predetermined engine speed and
vehicle speed range, this DTC will set. This DTC runs
only manual transmission.
Condition for Running the DTC

• The ignition switch is ON.
• The engine speed is higher than 665 RPM
• The vehicle speed is lower than 2 km/h (1.2 MPH).
• The clutch pedal is released after once depressed.
Condition for Setting the DTC • The ECM detects that the neutral switch signal is
continuously OFF (other than neutral) during three
consecutive driving cycles.
Action Taken When the DTC Sets • The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
Condition for Clearing the MIL/DTC
Important: • Following conditions must be met two consecutive
driving cycles. (One driving cycle: Ignition switch
ON > Engine run > Ignition switch OFF for 10
seconds)
- The engine speed is higher than 665 RPM
- The vehicle speed is lower than 2 km/h (1.2 MPH)
- The clutch pedal is released after once depressed
- Neutral position

- After the above procedure is done, a history
DTC clears after 40 consecutive driving cycles
without a fault. Or clear with the scan tool.
Diagnostic Aids
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.

DTC P1520 (Symptom Code B) (Flash Code 47)
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or Engine Control Module (ECM)
Connector End Views

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 the scan tool. 2. Turn ON the ignition, with the engine OFF.
3. Observe the Neutral Switch parameter with the scan tool while shift to neutral and other
positions.
Does the scan tool indicate ON when the position is
neutral and OFF when other than the neutral? 

Go to Diagnostic Aids Go to Step 3
3 1. Turn OFF the ignition. 2. Inspect the ECM (10A) fuse (EB-4) in the engine room fuse block.
Is the ECM (10A) fuse (EB-4) open? 

Go to Step 4 Go to Step 5
4 Replace the ECM (10A) fuse (EB-4). If the fuse continues to open, repair the short to ground on one
of the circuits that is fed by the ECM (10A) fuse (EB-
4) or replace the shorted attached component fed by
the ECM (10A) fuse (EB-4).
Did you complete the repair? 

Go to Step 13 

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ISUZU KB P190 2007