2007 ISUZU KB P190 Circuit

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-293
DTC P2228 or P2229 (Flash Code 71)
Circuit Description
The barometric pressure (BARO) sensor is located on
the intake manifold. The BARO sensor is a transducer
that varies voltage according to changes the barometric
pressure. The sensor has the following circuits.
• 5 volts reference circuit.
• Low reference circuit.
• BARO sensor signal circuit.
The BARO sensor provides a signal to the ECM on the
signal circuit, which is relative to the pressure changes
of the barometric pressure. The ECM should detect a
low signal voltage at a low barometric pressure, such
as high altitude place. The ECM should detect high
signal voltage at a high barometric pressure. 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 or high signal
voltage, DTC P2228 or P2229 will set.
Condition for Running the DTC • DTCs P0652 and P0653 are not set.
• The battery voltage is more than 9 volts.
• The ignition switch is ON.
Condition for Setting the DTC • The ECM detects that the BARO sensor signal voltage is less than 0.1 volts for 3 seconds. (DTC
P2228) • The ECM detects that the BARO sensor signal
voltage is less than 4.3 volts for 3 seconds. (DTC
P2229)
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 uses a BARO substitution of default value.
• The ECM limits fuel injection quantity.
• The ECM inhibits EGR control.
• 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.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P2228
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 Information with a scan tool.
Is DTC P0652 also set? —
Go to DTC P0652 Go to Step 3
3 Observe the Barometric Pressure (BARO) Sensor
parameter with a scan tool.
Is the BARO Sensor parameter less than the
specified value? 0.1 volts
Go to Step 4 Go to Diagnostic
Aids
4 1. Turn OFF the ignition.
2. Disconnect the BARO sensor harness connector.
3. Connect a DMM between the 5 volts reference circuit (pin 3 of E-40) and a known good
ground.
4. Turn ON the ignition, with the engine OFF.
Is the DMM voltage more than the specified value? 4.7 volts
Go to Step 5 Go to Step 6

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ISUZU KB P190 2007

6E-294 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
5Connect a 3-amp fused jumper wire between the 5
volts reference circuit and the signal circuit (pins 2
and 3 of E-40).
Is the BARO Sensor parameter more than the
specified value? 4.7 volts
Go to Step 8 Go to Step 7
6 1. Test the 5 volts reference circuit between the
ECM (pin 19 of E-90) and the BARO sensor
(pin 3 of E-40) for an open circuit or high
resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 12 Go to Step 9
7 1. Test the signal circuit between the ECM (pin
18 of E-90) and the BARO sensor (pin 2 of E-
40) for the following conditions:
• An open circuit
• A short to ground
• A short to the low reference circuit
• High resistance
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 12 Go to Step 9
8 1. Inspect for an intermittent and for poor
connections at the harness connector of the
BARO sensor (pins 2 and 3 of E-40).
2. 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 poor connections at the harness connector of the
ECM (pins 18 and 19 of E-90).
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 BARO sensor. Refer to BARO Sensor
Replacement.
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
—
121. Reconnect all previously disconnected
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 13
Step
Action Value(s)Yes No

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-295
Circuit/ System Testing DTC P2229
13Observe 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
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. Observe the Barometric Pressure (BARO) Sensor parameter with a scan tool.
Is the BARO Sensor parameter more than the
specified value? 4.3 volts
Go to Step 3 Go to Diagnostic
Aids
3 Monitor the DTC Information with a scan tool.
Is DTC P0653 also set? —
Go to Step 4 Go to Step 5
4 1. Turn OFF the ignition.
2. Disconnect the BARO sensor harness connector.
3. Turn ON the ignition, with the engine OFF.
Is the BARO Sensor parameter less than the
specified value? 0.1 volts
Go to DTC P0653 Go to Step 7
5 1. Turn OFF the ignition.
2. Disconnect the BARO sensor harness connector.
3. Turn ON the ignition, with the engine OFF.
Is the BARO Sensor parameter less than the
specified value? 0.1 volts
Go to Step 6 Go to Step 7
6 Connect a test lamp between the low reference
circuit (pin 1 of E-40) and battery voltage.
Does the test lamp illuminate? —
Go to Step 9 Go to Step 8
7 Important:
The BARO sensor may be damaged if
the sensor signal circuit is shorted to a voltage
source.
1. Test the signal circuit between the ECM (pin 18 of E-90) and the BARO sensor (pin 2 of E-
40) 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 13 Go to Step 12
8 1. Test the low reference circuit between the
ECM (pin 17 of E-90) and the BARO sensor
(pin 1 of E-40) for an open circuit or high
resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 10

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-297
DTC P2621 or P2622 (Flash Code 94)
Circuit Description
The accelerator pedal position (APP) sensor is
mounted on the accelerator pedal control assembly.
The analogue APP signals are converted by the ECM
into a pulse width modulation (PWM) signal. This
converted signal is sent from the ECM to the TCM to
determine appropriate shift points depending on the
accelerator pedal pressing amount. If the ECM detects
an improper voltage level on the APP PWM signal
circuit, DTC P2621 or P2622 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 APP PWM signal circuit for longer than 3 seconds.
(DTC P2621) • The ECM detects a high voltage condition on the
APP PWM signal circuit for longer than 3 seconds.
(DTC P2622)
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.
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.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P2621
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 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. Back probe a DMM between the accelerator pedal position (APP) signal circuit of the TCM
harness connector (pin 16 of C-94) and a
known good ground.
3. Turn ON the ignition, with the engine OFF.
Is the DMM voltage more than the specified value? 10.0 volts
Go to Step 6 Go to Step 4
4 Is the DMM voltage more than the specified value
at Step 3? 2.0 volts
Go to Step 7 Go to Step 5
5 Repair the short to ground between the ECM (pin
56 of C-58) and the TCM (pin 16 of C-94).
Did you complete the repair? —
Go to Step 11
—
61. Test the signal circuit between the ECM (pin
56 of C-58) and the TCM (pin 16 of C-94) for
an open circuit or high resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 8

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ISUZU KB P190 2007

6E-298 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Circuit/ System Testing DTC P2622
71. Turn OFF the ignition.
2. Disconnect the TCM harness connector.
3. Inspect for an intermittent and for a poor connection at the harness connector of the
TCM (pin 16 of C-94).
4. 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 56 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 Important:
Replacement TCM must be
programmed.
Replace the TCM. Refer to TCM Replacement.
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
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 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
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 Information with a scan tool.
Does the DTC fail this ignition? —
Go to Step 3 Go to Diagnostic
Aids

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-299
31. Turn OFF the ignition.
2. Disconnect the TCM harness connector.
3. Connect a test lamp between the accelerator pedal position (APP) signal circuit of the TCM
harness connector (pin 16 of C-94) and a
known good ground.
4. Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate? —
Go to Step 4 Go to Step 5
4 1. Test the signal circuit between the ECM (pin
56 of C-58) and the TCM (pin 16 of C-94) 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 Important:
Replacement TCM must be
programmed.
Replace the TCM. Refer to TCM Replacement.
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
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
Step
Action Value(s)Yes No

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ISUZU KB P190 2007

6E-300 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC U0001 or U0101 (Flash Code 84 or 85)
Circuit Description
The ECM, the transmission control module (TCM), the
immobilizer control unit (ICU), the data recording
module (DRM), instrument panel (IP) cluster and scan
tool communicate control and diagnostic information
via a controller area network (CAN) communication
bus. The ECM monitors CAN operational status by
expecting a constant flow of messages from the TCM,
ICU, DRM and IP cluster. If the ECM fails to send or
receive an expected message from the TCM, ICU,
DRM and IP cluster, DTC U0001 or U0101 will set
depending on what communication is lost.
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 that the CAN Bus OFF status. (DTC U0001)
• The ECM detects that the CAN Bus messages from the TCM are not being received. (DTC
U0101) 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 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.
Notice: • If the TCM has DTCs set, clear the DTCs in the TCM first.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC U0001 or U0101
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 Refer to Scan Tool Does Not Communicate with
The CAN Device in this section.
Did you complete the action? —
Go to Step 3
—
31. Reconnect all previously disconnected
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 2 Go to Step 4
4 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-301
DTC U0167 (Flash Code 177)
Circuit Description
The ECM communicates with the immobilizer control
unit (ICU) to execute immobilizer function. The ECM
sends request signal to the ICU. The ECM receives
response signal from the ICU. Both communication
signals are carried out via a controller area network
(CAN) communication bus. If the ECM does not detect
a response signal from the ICU, this DTC will set.
Condition for Setting the DTC • The ECM does not receive an immobilizer response signal from the ICU.
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.
• Electromagnetic interference may affect intermittent condition.
• Any communication fault with the ICU may set this DTC.
Circuit/ System Testing DTC U0167
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, with the engine OFF.
4. Monitor the DTC Information with a scan tool.
Is DTC U0001 also set? —
Go to DTC U0001 Go to Step 3
3 Attempt to communicate with the immobilizer
control unit (ICU) via the Immobilizer Data table.
Does the scan tool communicate with the ICU? —
Go to Step 4 Go to Diagnostic
System Check - Immobilizer Controls
4 Monitor the immobilizer DTC Information with a
scan tool.
Does the immobilizer DTCs fail this ignition which
begin with B or U? —
Go to Applicable
DTC in Immobilizer
Section Go to Step 5
5 Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 6
—
61. Clear the DTCs with a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Turn ON the ignition, with the engine OFF.
Did the DTC fail this ignition? —
Go to Step 2 Go to Step 7
7 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