2007 ISUZU KB P190 sensor

Engine Control System (4JH1) 6E-163
Step Action Value(s) Yes No
5 1. Remove the vehicle speed sensor (VSS). Refer
to Vehicle Speed Sensor (VSS) Replacement in
this section.
2. Visually inspect the VSS for the following conditions: • Physical damage
• Being loose
• Improper installation
• For transmission output shaft teeth damage
3. Repair or replace as necessary.
Did you find and correct the condition? 

Go to Step 20 Go to Step 6
6 1. Turn OFF the ignition. 2. Disconnect the VSS harness connector.
3. Connect a test lamp between the ignition voltage feed circuit of the VSS harness (pin 1 of E-44
connector) and a known good ground.
4. Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate? 

Go to Step 7 Go to Step 9
7 1. Turn ON the ignition, with the engine OFF. 2. Connect a test lamp between the ignition voltage feed circuit and low reference circuit of the VSS
harness (pins 1 and 2 of E-44 connector).
Does the test lamp illuminate? 

Go to Step 8 Go to Step 10
8 1. Turn ON the ignition, with the engine OFF. 2. Intermittently jump the signal circuit of the VSS (pin 3 of E-44 connector) with a test lamp that is
connected to a known good ground while
monitoring the Vehicle Speed parameter with the
scan tool.
Does the scan tool indicate any vehicle speed when
the circuit is intermittently pulled to ground? 

Go to Step 14 Go to Step 11
9 Repair the open or high resistance in the VSS ignition voltage feed circuit between the Meter (15A)
fuse (C-14) and the VSS (pin 1 of E-44 connector).
Did you complete the repair? 

Go to Step 20 
10 Repair the open or high resistance in the VSS low
reference circuit between the VSS (pin 2 of E-44
connector) and the chassis ground.
Did you complete the repair? 

Go to Step 20 
11 1. Turn OFF the ignition.
2. Remove the instrument panel cluster (IPC) in order to disconnect the B-24 harness connector.
3. Disconnect the IPC B-24 harness connector.
4. Turn ON the ignition, with the engine OFF.
5. Intermittently jump the signal output circuit of the VSS signal (pin 10 of B-24 connector) with a test
lamp that is connected to a known good ground
while monitoring the Vehicle Speed parameter
with the scan tool.
Does the scan tool indicate any vehicle speed when
the circuit is intermittently pulled to ground? 

Go to Step 12 Go to Step 13

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

6E-164 Engine Control System (4JH1)
Step Action Value(s) Yes No
12 1. Test the VSS signal circuit between the VSS (pin
3 of E-44 connector) and the IPC (pin 9 of B-23
connector) 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 20 Go to Step 15
13 1. Test the VSS signal circuit between the engine control module (ECM) (pin 68 of C-56 connector)
and the IPC (pin 10 of B-23 connector) 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 20 Go to Step 16
14 1. Turn OFF the ignition. 2. Disconnect the VSS harness connector.
3. Inspect for an intermittent and for poor connections at the harness connector of the VSS
(pin 1, 2 and 3 of E-44 connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 20 Go to Step 17
15 1. Turn OFF the ignition. 2. Disconnect the IPC B-23 harness connector.
3. Inspect for an intermittent and for poor connections at the harness connector of the IPC
(pins 9 and 10 of B-23 connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 20 Go to Step 18
16 1. Turn OFF the ignition. 2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for a poor connection on the VSS signal circuit at the
harness connector of the ECM (pin 68 of C-56
connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 20 Go to Step 19
17 Replace the VSS. Refer to Vehicle Speed Sensor (VSS) Replacement in this section.
Did you complete the replacement? 

Go to Step 20 
18 Replace the IPC (meter assembly). Refer to Meter
Replacement in electrical section.
Did you complete the replacement? 

Go to Step 20 
19 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 20 

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

6E-188 Engine Control System (4JH1)
DTC P1105 (Symptom Code 1) (Flash Code 86)
Circuit Description
The barometric pressure (BARO) sensor is installed
inside of the engine control module (ECM) and converts
the BARO into a voltage signal. The ECM uses this
voltage signal to calibrate the fuel injection quantity and
injection timing for altitude compensation. If the ECM
detects an excessively high BARO sensor signal
voltage, this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.

Condition for Setting the DTC
• The ECM detects that the BARO sensor signal
voltage is more than 4.4 volts 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 uses a BARO substitution of 1013 hPa.
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.

DTC P1105 (Symptom Code 1) (Flash Code 86)


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: 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 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


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Control System (4JH1) 6E-189
DTC P1105 (Symptom Code 2) (Flash Code 86)
Circuit Description
The barometric pressure (BARO) sensor is installed
inside of the engine control module (ECM) and converts
the BARO into a voltage signal. The ECM uses this
voltage signal to calibrate the fuel injection quantity and
injection timing for altitude compensation. If the ECM
detects an excessively low BARO sensor signal voltage,
this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.

Condition for Setting the DTC
• The ECM detects that the BARO sensor signal
voltage is less than 1.5 volts 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 uses a BARO substitution of 1013 hPa.
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.

DTC P1105 (Symptom Code 2) (Flash Code 86)


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: 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 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



BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

6E-190 Engine Control System (4JH1)
DTC P1120 (Symptom Code 1) (Flash Code 21)
Circuit Description
The accelerator pedal position (APP) sensor is mounted
on the intake throttle assembly. The engine control
module (ECM) uses the APP sensors to determine the
amount of acceleration or deceleration desired by the
person driving the vehicle via the fuel injection control.
The APP sensor has the following circuits.
• 5 volts reference circuit
• Low reference circuit
• APP sensor signal circuit
The ECM supplies 5 volts to the APP sensor on the 5
volts reference circuit. The ECM also provides a ground
on the low reference circuit. The APP sensor provides a
signal to the ECM on the APP sensor signal circuit,
which is relative to the position changes of the
accelerator pedal angle. The ECM monitors the
APP
sensor signal for voltages outside the normal range o
f
the APP sensor. If the ECM detects an excessively high
APP sensor signal voltage, this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.

Condition for Setting the DTC
• The ECM detects that the APP sensor signal
voltage is more than 4.5 volts for 0.5 seconds.
Action Taken When the DTC Sets • The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
• The ECM uses an engine speed substitution o
f
1400 RPM.
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.

DTC P1120 (Symptom Code 1) (Flash Code 21)
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.
4. Monitor the Diagnostic Trouble Code (DTC) Information with the 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 accelerator pedal position (APP) sensor harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Observe the Accelerator Pedal Position (APP) parameter with the scan tool.
Does the APP parameter less than the specified
value? 1%
Go to Step 4 Go to Step 5
4 1. Turn OFF the ignition. 2. Connect a test lamp between the low reference circuit of the APP sensor harness (pin 1 of E-22
connector) and battery voltage.
3. Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate? 

Go to Step 11 Go to Step 8
5 1. Turn OFF the ignition. 2. Connect a DMM between the 5 volts reference circuit of the APP sensor harness (pin 3 of E-22
connector) and a known good ground.
3. Turn ON the ignition, with the engine OFF.
Is the DMM voltage more than the specified value? 4.5 volts
Go to Step 6 Go to Step 9

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Control System (4JH1) 6E-191
Step Action Value(s) Yes No
6 Is the DMM voltage less than the specified value at
step 5? 5.5 volts
Go to Step 7 Go to Step 10
7 Important: The APP sensor may be damaged if the
sensor signal circuit is shorted to a voltage source.
1. Test the signal circuit between the engine control module (ECM) (pin 38 of C-56 connector) and
the APP sensor (pin 2 of E-22 connector) 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 15 Go to Step 14
8 . Test the low reference circuit between the 1ECM (pin 49 of C-56 connector) and the APP sensor
(pin 1 of E-22 connector) for an open circuit or
high resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 15 Go to Step 12
9 1. Test the 5 volts reference circuit between the ECM (pin 57 of C-56 connector) and the APP
sensor (pin 3 of E-22 connector) for the following
conditions: • A short to ground
• A short to the low reference circuit
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 15 Go to Step 14
10 1. Test the 5 volts reference circuit between the ECM (pin 57 of C-56 connector) and the APP
sensor (pin 3 of E-22 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 15 Go to Step 14
11 1. Turn OFF the ignition. 2. Inspect for an intermittent and for a poor connection at the harness connector of the APP
sensor (pin 1 of E-22 connector).
3. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 15 Go to Step 13
12 1. Turn OFF the ignition. 2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for a poor connection on the APP sensor circuit at the
harness connector of the ECM (pin 49 of C-56
connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 15 Go to Step 14
13 Replace APP sensor. Refer to Accelerator Pedal Position (APP) Sensor Replacement in this section.
Did you complete the replacement? 

Go to Step 15 
14 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 15 

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Control System (4JH1) 6E-193
DTC P1120 (Symptom Code 7) (Flash Code 21)
Circuit Description
The accelerator pedal position (APP) sensor is mounted
on the intake throttle assembly. The engine control
module (ECM) uses the APP sensors to determine the
amount of acceleration or deceleration desired by the
person driving the vehicle via the fuel injection control.
The APP sensor has the following circuits.
• 5 volts reference circuit
• Low reference circuit
• APP sensor signal circuit
The ECM provides 5 volts reference voltage through the
reference circuit to the APP sensor. The ECM monitors
the voltage on the 5 volts reference circuit. If the ECM
detects an excessively high APP sensor 5 volts
reference voltage, this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.

Condition for Setting the DTC
• The ECM detects that the APP sensor voltage
supply circuit is more than 5.2 volts for 0.5
seconds.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
• The ECM uses an engine speed substitution o
f
1400 RPM.
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.

DTC P1120 (Symptom Code 7) (Flash Code 21)
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.
4. Monitor the Diagnostic Trouble Code (DTC) Information with the scan tool.
Does the DTC fail this ignition? 

Go to Step 3 Go to Diagnostic
Aids
3 1. Test the 5 volts reference circuit between 1the engine control module (ECM) (pin 57 of C-56
connector) and the accelerator pedal position
(APP) sensor (pin 3 of E-22 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 5 Go to Step 4
4 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 5 
5 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. Turn ON the ignition, with the engine OFF.
5. Fully depress and release the accelerator pedal many times.
6. Monitor the DTC Information with the scan tool.
Did the DTC fail this ignition? 

Go to Step 3 Go to Step 6

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Control System (4JH1) 6E-195
DTC P1120 (Symptom Code 9) (Flash Code 21)
Circuit Description
The accelerator pedal position (APP) sensor is mounted
on the intake throttle assembly. The engine control
module (ECM) uses the APP sensors to determine the
amount of acceleration or deceleration desired by the
person driving the vehicle via the fuel injection control.
The APP sensor has the following circuits.
• 5 volts reference circuit
• Low reference circuit
• APP sensor signal circuit
The ECM provides 5 volts reference voltage through the
reference circuit to the APP sensor. The ECM monitors
the voltage on the 5 volts reference circuit. If the ECM
detects an excessively high APP sensor 5 volts
reference voltage, this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.

Condition for Setting the DTC
• The ECM detects that the APP sensor voltage
supply circuit is less than 4.6 volts for 0.5 seconds.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
• The ECM uses an engine speed substitution o
f
1400 RPM.
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.
Test Description
The number below refers to the step number on the
diagnostic table.
3. If the APP sensor 5 volts reference circuit between
the ECM and the sensor is normal, the sensor signal
correlation DTC P1120 (Symptom Code E) will set.

DTC P1120 (Symptom Code 9) (Flash Code 21)
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.
4. Monitor the Diagnostic Trouble Code (DTC) Information with the 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 accelerator pedal position (APP) sensor harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Depress and release the accelerator pedal many times.
5. Monitor the DTC Information with the scan tool.
Does DTC P1120 (Symptom Code E) set, but not
DTC P1120 (Symptom Code 9)? 

Go to Step 5 Go to Step 4
4 1. Test the 5 volts reference circuit between the engine control module (ECM) (pin 57 of C-56
connector) and the APP sensor (pin 3 of E-22
connector) for the following conditions: • A short to ground
• A short to the low reference circuit
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 7 Go to Step 6

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007