2007 ISUZU KB P190 vacuum

Engine Control System (4JH1) 6E-103
DTC P0216 (Symptom Code A, B) (Flash Code 54)
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 timing device changes the optimum injection
timing against various engine conditions. The
pressure of the fuel fed from the feed pump is
adjusted and it acts to the timing plunger by TCV
controlled fuel pressure. (
The TCV is installed to the
fuel injection pump rear side and it is controlled by dut
y
ratio cycle from the PCU.) The timing plunger is
connected to the cam ring by a ball pin. Axial
movement of the timing plunger is transferred to the
cam ring in the form of rotational movement.
Movement to the right of the timing plunge
r
advances injection timing.
If the PCU detects an
excessive difference between actual and desired fuel
injection timing, this DTC will set.
Condition for Running the DTC
Symptom Code A
• The engine speed is higher than 700 RPM.
• The fuel injection quantity is higher than 4 mg/strk.
Symptom Code B
• The engine speed is higher than 2014 RPM.
Condition for Setting the DTC
Symptom Code A
• The PCU monitored actual fuel injection timing is
advanced more than desired by 3°CA for longe
r
than 12 seconds or retarded more than desired by
6°CA for longer than 12 seconds.
Symptom Code B
• The PCU monitored actual fuel injection timing is
oscillated higher than desired by 5.2°CA.
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:
• The fuel injection pump installation with incorrect
mechanical timing may set this DTC.
• This DTC most likely indicate loss fuel pressure by
restricted fuel line. Inspect the fuel line restriction
between the fuel injection pump and fuel tank.
• The fuel system from the fuel tank(s) to the fuel
injection pump is under a slight vacuum with the
engine running. As a result, air can enter the fuel
system if these connections are not tight or if there
is a crack in one of the fuel hoses. Air in the fuel
system will cause fuel injection pump internal
pressure fluctuations especially at high engine
speed and load, which may set this DTC.
• Improper fuel will cause this DTC to set. Inspect
fuel waxing or icing that is caused by an incorrect
fuel type used in winter season or water intrusion
in the fuel system.
• Contaminated fuel will cause this DTC to set.
Inspect the pipe connector fixing bolt (eye bolt) on
the fuel injection pump suction side.
Important:
If the fuel tank is empty or near empty, air might be
allowed to go into the fuel system. W ith air in the fuel
system, smooth flow of fuel into the fuel injection pump
is interrupted and this DTC may set. Perform bleeding
of fuel system after refilling. Refer to air bleeding
procedure in fuel system section.

DTC P0216 (Symptom Code A, B) (Flash Code 54)

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

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ISUZU KB P190 2007

6E-104 Engine Control System (4JH1)
Step Action Value(s) Yes No
2 1. Install the scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine and let idle for 30 seconds.
4. Monitor the Diagnostic Trouble Code (DTC) Information with the scan tool.
Is DTC P0335 (Symptom Code B or D), P1335
(Symptom Code A) or P1345 (Symptom Code A)
set? 

Go to Applicable DTC Go to Step 3
3 1. Turn OFF the engine. 2. Place the transmission in park or neutral (P or N) and set the park brake.
3. Start the engine and let engine idle for 30 seconds while observing the Actual Injection
Timing parameter with the scan tool.
4. Accelerate the engine and keep the constant engine speed around 2000 RPM while observing
the Actual Injection Timing parameter with the
scan tool.
5. Accelerate the engine and keep the constant engine speed around 3000 RPM while observing
the Actual Injection Timing parameter with the
scan tool.
Does the Actual Injection Timing parameter follow
the Desired Injection Timing within 2°CA on each
engine speed? 

Go to Diagnostic Aids Go to Step 4
4 1. Turn OFF the ignition. 2. Check the fuel system line connections between the fuel tank and the fuel injection pump for
tightness and all fuel hoses for cuts, cracks and
for the use of proper clamps.
Notice: The fuel system from the fuel tank(s) to the
fuel injection pump is under a slight vacuum with the
engine running. As a result, air can enter the fuel
system if these connections are not tight. Air in the
fuel system will cause fuel injection pump internal
pressure fluctuations especially at high engine
speed and load, which may set this DTC.
3. Pump the priming pump on the fuel filter until it becomes firm. If there is a leak on the suction
side of the fuel system between the priming
pump and the fuel injection pump, the priming
pump will not build up sufficient firmness and fuel
leakage may occur.
4. Repair or replace as necessary.
Did you find and correct the condition? 

Go to Step 9 Go to Step 5

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-105
Step Action Value(s) Yes No
5 1. Remove the fuel hose that connects to the fuel
injection pump suction side.
2. Remove the fuel pipe connector that connects to the fuel injection pump suction side.
3. Inspect the eye bolt for any type of restriction or collapsed gauze filter.
Notice: If any type of restriction found, check for a
condition that causes contaminated fuel, such as the
customer is using an aftermarket fuel filter or
extended maintenance interval.Also inspect fuel
waxing or icing that is caused by an incorrect fuel
type used in winter season or water intrusion in the
fuel system.
4. Repair or replace as necessary.
Did you find and correct the condition? 

Go to Step 9 Go to Step 6
6 1. Disconnect the fuel hose that connects to the fuel injection pump suction side. In order to
measure the discharged fuel amount, put the
hose into a bottle or a container.
2. Pump the priming pump on the fuel filter.
Notice: If there is a leak on the suction side of the
fuel system, the fuel from the disconnected hose will
not flow out sufficiently and fuel leakage may occur.
Also if there is a restriction on the suction side of the
fuel system, the fuel from the disconnected hose will
not flow out sufficiently that is most likely caused by
clogged fuel filter or kinked fuel hose or pipe.
3. Draw fuel from the fuel tank at the fuel line (as close to the fuel tank as possible) going to the
fuel pickup tube to verify a clean stream of fuel
comes out (use the hand-held vacuum pump 5-
8840-0279-0/J-23738-A with a clear hose or
equivalent). This will ensure the fuel pickup tube
is not cracked drawing air into the fuel line.
4. Repair any fuel system leaks and restrictions as necessary.
Did you find and correct the condition? 

Go to Step 9 Go to Step 7

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-107
DTC P0243 (Symptom Code 3) (Flash Code 64)
Circuit Description
The engine control module (ECM) controls the
turbocharger wastegate valve based on the barometric
pressure in order to reduce turbocharger spinning
speeds at high altitude area. The ECM controls the
turbocharger wastegate valve diaphragm by acting the
regulated vacuum pressure via controlling the solenoid
valve. The vacuum pressure sensor monitors the
regulated vacuum pressure to the turbocharge
r
wastegate valve. The ECM calculates desired vacuum
pressure and it compares the calculated desired
vacuum pressure to the actual value to determine the
solenoid valve position. W hen the actual vacuum
pressure is higher than the desired value, the solenoid
valve is closed to decrease the vacuum pressure. An
expected vacuum pressure amount should be detected
while the engine running. If the ECM detects the actual
vacuum pressure amount is higher than desired
vacuum pressure amount, this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.
• The barometric pressure (BARO) is between 0
hPa and 3500 hPa.
• The intake air temperature (IAT) is between -50°C
(-58 °F) and 200°C (392°F).
• The engine coolant temperature (ECT) is between
-50°C (-58 °F) and 150°C (302°F)
Condition for Setting the DTC
• The ECM detects that the vacuum pressure is 50
hPa higher than the desired vacuum pressure for
3 seconds. This indicates excessive high vacuum
pressure.
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.
• The ECM uses an EGR solenoid valve control
substitution of 10%.
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.
• Misrouted vacuum hoses will cause this DTC to
set.
Test Description
The numbers below refer to the step number on the
diagnostic table.
4. A skewed vacuum pressure sensor value (shifted to
a high pressure) can set this DTC. The Vacuum
Pressure on the scan tool should read near doubled
barometric pressure (BARO) with the key ON and
engine OFF.
5. A skewed BARO sensor value (shifted to a lowe
r
pressure) may set this DTC. The BARO on the scan
tool should read near surrounding barometric pressure.

DTC P0243 (Symptom Code 3) (Flash Code 64)
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 and let idle for 30 seconds.
4. Monitor the Diagnostic Trouble Code (DTC) Information with the scan tool.
Is DTC P0105 (Symptom Code 1, 2, 7 or 9) or
P0243 (Symptom Code 4 or 8) set? 

Go to Applicable DTC Go to Step 3

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ISUZU KB P190 2007

6E-108 Engine Control System (4JH1)
Step Action Value(s) Yes No
3 1. Turn OFF the ignition.
2. Inspect for the following conditions: • Vacuum hoses are damaged or kinked.
• Misrouted vacuum hoses.
• A turbocharger solenoid valve is damaged.
• A vacuum pump is damaged.
• A vacuum regulating valve is damaged.
• A turbocharger wastegate valve is
damaged.
• Contaminated, skewed or slow vacuum
pressure sensor.
3. Repair or replace as necessary.
Did you find and correct the condition? 

Go to Step 15 Go to Step 4
4 1. Turn ON the ignition, with the engine OFF. 2. Observe the Vacuum Pressure Sensor and Barometric Pressure (BARO) with the scan tool.
Does the scan tool indicate that the difference
between the Vacuum Pressure Sensor and doubled
BARO is less than the specified value? 10 hPa

Go to Step 7 Go to Step 5
5 1. Observe the BARO parameter with the scan tool.2. Compare the BARO value to the range specified in the altitude vs. barometric pressure table.
Refer to Altitude vs. Barometric Pressure.
Is the BARO parameter within the range specified? 

Go to Step 6 Go to Step 14
6 1. Turn OFF the ignition. 2. Disconnect the vacuum pressure sensor harness connector.
3. Inspect for an intermittent and for poor connections at the vacuum pressure sensor
harness connector (pins 1 and 3 of C-124
connector).
4. Disconnect the engine control module (ECM) harness connector.
5. Inspect for an intermittent, for poor connections and corrosion on each vacuum pressure sensor
circuit at the harness connector of the ECM (pins
82 and 85 of C-57 connector).
6. Test for high resistance on each vacuum pressure sensor circuit.
7. Test the vacuum pressure sensor signal circuit short to any other circuits.
8. Repair the connection(s) or circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 15 Go to Step 10
7 1. Turn OFF the ignition. 2. Disconnect the vacuum hose from the turbocharger wastegate valve that is connected
to the vacuum pressure sensor and the
turbocharger solenoid valve.
3. Connect a hand-held vacuum pump (5-8840- 0279-0/J-23738-A) to the turbocharger
wastegate valve. This test is in order to verify an
airtight of the turbocharger wastegate valve
inside.
4. Start the engine and let engine idle.
Does the hand-held vacuum pump indicate any
vacuum pressure? 

Go to Step 13 Go to Step 8

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-109
Step Action Value(s) Yes No
8 1. Turn OFF the ignition.
2. Disconnect the hand-held vacuum pump from the turbocharger wastegate valve.
3. Reconnect the vacuum hose to the turbocharger wastegate valve.
4. Disconnect the vacuum hose from the turbocharger solenoid valve that is connected to
the vacuum regulating valve “Z” port.
5. Connect a hand-held vacuum pump (5-8840- 0279-0/J-23738-A) to the disconnected vacuum
hose.
6. Start the engine and let engine idle.
Does the hand-held vacuum pump indicate less than
28 cmHg (11 inHg)? 

Go to Step 9 Go to Step 12
9 1. Turn OFF the ignition. 2. Disconnect the hand-held vacuum pump from the vacuum hose.
3. Reconnect the vacuum hose to the turbocharger solenoid valve.
4. Disconnect the vacuum hose from the vacuum pressure sensor that is connected to the
turbocharger solenoid valve and the turbocharger
wastegate valve.
5. Connect a hand-held vacuum pump (5-8840- 0279-0/J-23738-A) to the disconnected vacuum
hose.
6. Disconnect the vacuum pressure sensor harness connector in order to active turbocharger
solenoid valve.
7. Start the engine and let engine idle.
Does the needle of hand-held vacuum pump shake
between 0 and 20 cmHg (8 inHg)? 

Go to Step 10 Go to Step 11
10 Replace the vacuum pressure sensor. Refer to Vacuum Pressure Sensor Replacement in this
section.
Did you complete the replacement? 

Go to Step 15 

11 Replace the turbocharger solenoid valve. Refer to
Turbocharger Solenoid Valve Replacement in this
section.
Did you complete the replacement? 

Go to Step 15 

12 Replace the vacuum regulating valve.
Did you compete the replacement? 

Go to Step 15 

13 Replace the turbocharger wastegate valve. Refer to
Turbocharger in Engine Mechanical 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 
15 1. Reconnect all previously disconnected hoses 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 2 Go to Step 16

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Engine Control System (4JH1) 6E-111
DTC P0243 (Symptom Code 4) (Flash Code 64)
Circuit Description
The engine control module (ECM) controls the
turbocharger wastegate valve based on the barometric
pressure in order to reduce turbocharger spinning
speeds at high altitude area. The ECM controls the
turbocharger wastegate valve diaphragm by acting the
regulated vacuum pressure via controlling the solenoid
valve. The vacuum pressure sensor monitors the
regulated vacuum pressure to the turbocharge
r
wastegate valve. The ECM calculates desired vacuum
pressure and it compares the calculated desired
vacuum pressure to the actual value to determine the
solenoid valve position. W hen the actual vacuum
pressure is higher than the desired value, the solenoid
valve is closed to decrease the vacuum pressure. If the
ECM detects that an open circuit or short to ground on
the turbocharger 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 turbocharger solenoid valve control circuit fo
r
longer 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.
• The ECM uses a turbocharger solenoid valve
control substitution of 68%.
• The ECM uses an EGR solenoid valve control
substitution of 10%.
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 P0243 (Symptom Code 4) (Flash Code 64)
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 turbocharger solenoid valve harness connector.
3. Connect a test lamp between the voltage feed circuit of the turbocharger solenoid valve harness
(pin 1 of C-123 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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6E-112 Engine Control System (4JH1)
Step Action Value(s) Yes No
6 1. Connect a test lamp between the control circuit
of the turbocharger solenoid valve harness (pin 2
of C-123 connector) and battery voltage.
2. Turn ON the ignition, with the engine OFF.
Does the test lamp continuously illuminate? 

Go to Step 9 Go to Step 7
7 1. Keep the test lamp with connected. 2. Turn OFF the ignition.
3. Disconnect the vacuum pressure sensor harness connector in order to energize the turbocharger
solenoid valve.
4. Turn ON the ignition, with the engine OFF.
Does the test lamp blink? 

Go to Step 11 Go to Step 10
8 Repair the open circuit or high resistance on the voltage feed circuit between the ECM (10A) fuse
(EB-4) and the turbocharger solenoid valve (pin 1 of
C-123 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 turbocharger 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
10 1. Test the control circuit between the ECM (pin 96 of C-57 connector) and the turbocharger solenoid
valve (pin 2 of C-123 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
11 1. Turn OFF the ignition. 2. Disconnect the turbocharger solenoid valve harness connector.
3. Inspect for an intermittent and for poor connections at the harness connector of the
turbocharger solenoid valve (pins 1 and 2 of C-
123 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 turbocharger solenoid valve
circuit at the harness connector of the ECM (pin
96 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 turbocharger solenoid valve. Refer to Turbocharger 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