Engine Control System (4JH1) 6E-149
DTC P0400 (Symptom Code 4) (Flash Code 32)
Circuit Description
The engine control module (ECM) controls the exhaust
gas recirculation (EGR) flow amount based on the
engine speed, engine coolant temperature, intake ai
r
temperature, barometric pressure and fuel injection
quantity. The ECM controls the EGR valve b
y
controlling the EGR solenoid valve. The mass air flo
w
(MAF) sensor monitors EGR gas flow amount. An
expected MAF amount should be detected while the
engine running. If the ECM detects that an open circuit
or short to ground on the EGR solenoid valve control
circuit, this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.
Condition for Setting the DTC • The ECM detects that the low voltage condition on
the EGR solenoid valve control circuit for longe
r
than 3 seconds when the solenoid valve is
commanded OFF.
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.
DTC P0400 (Symptom Code 4) (Flash Code 32)
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. 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 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 15
5 1. Turn OFF the ignition.
2. Disconnect the EGR control solenoid valve harness connector.
3. Connect a test lamp between the voltage feed circuit of the EGR control solenoid valve harness
(pin 1 of C-115 connector) and a known good
ground.
4. Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate?
Go to Step 6 Go to Step 8
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ISUZU KB P190 2007
6E-150 Engine Control System (4JH1)
Step Action Value(s) Yes No
6 1. Connect a test lamp between the control circuit
of the EGR solenoid valve harness (pin 2 of C-
115 connector) and battery voltage.
2. Perform the EGR Solenoid Valve test with the scan tool.
3. Command the EGR Solenoid Valve ON with the scan tool.
Does the test lamp illuminate when commanded ON
with the scan tool?
Go to Step 7 Go to Step 9
7 Command the EGR Solenoid Valve OFF with the scan tool.
Does the test lamp continuously illuminate same as
step 6 when commanded OFF with the scan tool
(the test lamp slightly illuminates if the circuit is
normal when commanded OFF)?
Go to Step 10 Go to Step 11
8 Repair the open circuit or high resistance on the voltage feed circuit between the ECM (10A) fuse
(EB-4) and the EGR solenoid valve (pin 1 of C-115
connector).
Did you complete the repair?
Go to Step 15
9 1. Test the control circuit between the engine
control module (ECM) (pin 97 of C-57 connector)
and the EGR solenoid valve (pin 2 of C-115
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
10 1. Test the control circuit between the ECM (pin 97 of C-57 connector) and the EGR solenoid valve
(pin 2 of C-115 connector) for a short to ground.
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. Disconnect the EGR solenoid valve harness connector.
3. Inspect for an intermittent and for poor connections at the harness connector of the EGR
solenoid valve (pins 1 and 2 of C-115 connector).
4. 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 EGR solenoid valve control
circuit at the harness connector of the ECM (pin
97 of C-57 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 the EGR solenoid valve. Refer to EGR Solenoid Valve 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
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ISUZU KB P190 2007
Engine Control System (4JH1) 6E-151
Step Action Value(s) Yes No
15 1. Reconnect all previously disconnected fuse or
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 3 Go to Step 16
16 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-157
DTC P0500 (Symptom Code 1, A) (Flash Code 24)
Circuit Description
The vehicle speed sensor (VSS) is used by the engine
control module (ECM) and speedometer, which
generates a speed signal from the transmission output
shaft. The VSS has the following circuits.
• Ignition voltage feed circuit
• VSS signal circuit
• VSS low reference circuit
The VSS uses a hall effect element. It interacts with the
magnetic field created by the rotating magnet and
outputs square wave pulse signal. The 12 volts
operating supply from the Meter fuse (except 2W D with
A/T) or Back Up fuse (2W D with A/T). The ECM
calculates the vehicle speed by the VSS. If the vehicle
is 2W D with automatic transmission, VSS signals are
sent from the transmission control module (TCM). If the
ECM detects VSS signals are generated with high
frequencies, this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.
Condition for Setting the DTC
• The ECM detects that the vehicle speed is highe
r
than 200 km/h (125 MPH) for 5 seconds.
(Symptom Code 1)
•
The ECM detects that the vehicle speed senso
r
signal frequency is too high for 0.6 seconds.
(Symptom Code A)
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 vehicle speed substitution of 5
km/h (3 MPH) for engine control.
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
• Electrical or magnetic interference may affect
intermittent condition.
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
DTC P0500 (Symptom Code 1, A) (Flash Code 24)
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or Engine Control Module (ECM)
Connector End Views
Chart for 2WD with 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. Inspect all of the circuits going to the automatic transmission (A/T) vehicle speed sensor (VSS)
for the following: • Routed too closely to fuel injection solenoid
wiring or components
• Routed too closely to after-market add-on
electrical equipment
• Routed too closely to solenoids, relays, and
motors
2. If you find incorrect routing, correct the harness routing.
Did you find and correct the condition?
Go to Step 7 Go to Step 3
3 1. Turn OFF the ignition. 2. Disconnect the A/T VSS harness connector.
3. Inspect for an intermittent and for poor connections at the harness connector of the A/T
VSS (pins 1, 2 and 3 of E-30 connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition?
Go to Step 7 Go to Step 4
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ISUZU KB P190 2007
6E-160 Engine Control System (4JH1)
DTC P0500 (Symptom Code B) (Flash Code 24)
Circuit Description
The vehicle speed sensor (VSS) is used by the engine
control module (ECM) and speedometer, which
generates a speed signal from the transmission output
shaft. The VSS has the following circuits.
• Ignition voltage feed circuit
• VSS signal circuit
• VSS low reference circuit
The VSS uses a hall effect element. It interacts with the
magnetic field created by the rotating magnet and
outputs square wave pulse signal. The 12 volts
operating supply from the Meter fuse (except 2W D with
A/T) or Back Up fuse (2W D with A/T). The ECM
calculates the vehicle speed by the VSS. If the vehicle
is 2W D with automatic transmission, VSS signals are
sent from the transmission control module (TCM). If the
ECM detects VSS signals are not generated, this DTC
will set.
Condition for Running the DTC
• The ignition switch is ON.
• The engine speed is higher than 3600 RPM.
• The fuel injection quantity is more than 41 mg/strk.
Condition for Setting the DTC
• The ECM detects that the vehicle speed is lowe
r
than 1.5 km/h (1 MPH) for 60 seconds.
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
• 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
• Electrical or magnetic interference may affect
intermittent condition.
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
DTC P0500 (Symptom Code B) (Flash Code 24)
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or Engine Control Module (ECM)
Connector End Views
Chart for 2WD with 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
P0722 set?
Go to Applicable
DTC in Automatic Transmission Section Go to Step 3
3 1. Drive the vehicle. 2. Select the data display function of engine control module (ECM).
3. Observe the Vehicle Speed parameter with the scan tool.
Does the Vehicle Speed parameter indicate correct
vehicle speed?
Go to Diagnostic Aids Go to Step 4
4 1. Turn OFF the ignition. 2. Disconnect the TCM harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Intermittently jump the VSS signal output circuit (pin A-10 of C-94 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 8 Go to Step 5
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ISUZU KB P190 2007
6E-162 Engine Control System (4JH1)
Step Action Value(s) Yes No
11 Replace the IPC (meter assembly). Refer to Meter
Replacement in electrical section.
Did you complete the replacement?
Go to Step 14
12 Important: Replacement TCM must be
programmed.
Replace the TCM. Refer to Transmission Control
Module (TCM) Replacement in the transmission
section.
Did you complete the replacement?
Go to Step 14
13 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 14
14 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. Drive the vehicle.
5. Observe the Vehicle Speed parameter with the scan tool.
Does the Vehicle Speed parameter indicate correct
vehicle speed?
Go to Step 15 Go to Step 2
15 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 except 2WD with 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. Drive the vehicle.
3. Observe the Vehicle Speed parameter with the scan tool.
Does the Vehicle Speed parameter indicate correct
vehicle speed?
Go to Diagnostic Aids Go to Step 3
3 1. Turn OFF the ignition. 2. Inspect the Meter (15A) fuse (C-14) in the cabin fuse block.
Is the Meter (15A) fuse (C-14) open?
Go to Step 4 Go to Step 5
4 Replace the Meter (15A) fuse (C-14). If the fuse continues to open, repair the short to ground on one
of the circuits that fed by the Meter (15A) fuse (C-14)
or replace the shorted attached component fed by
the Meter (15A) fuse (C-14).
Did you complete the repair?
Go to Step 20
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ISUZU KB P190 2007
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
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ISUZU KB P190 2007
Engine Control System (4JH1) 6E-165
Step Action Value(s) Yes No
20 1. Reconnect all previously disconnected fuse or
harness connector(s).
2. Clear the DTCs with the scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Drive the vehicle.
5. Observe the Vehicle Speed parameter with the scan tool.
Does the Vehicle Speed parameter indicate correct
vehicle speed?
Go to Step 21 Go to Step 3
21 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