2007 ISUZU KB P190 BATTERY

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

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

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

6E-306 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Glow Control System Check
Description
The glow control system consists of the ECM, the glow
relay, the glow indicator lamp and glow plugs. The glow
control system is operated when the engine coolant
temperature is low, which allows easier engine starting.
The ECM commands the glow relay ON for a certain
length of time at ignition switch is ON with engine OFF.
In after glow phase, the glow plugs remain energized
for a certain period with engine run.
Glow Control Operation • The glow indicator lamp illuminates between 0.5 seconds to 7 seconds depending upon the engine
coolant temperature. • The pre glow control system operates when the
engine coolant temperature is less than 30 °C
(86 °F).
• The after glow control system operates when the engine coolant temperature is less than 60 °C
(140 °F).
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing Glow Control System Check (1 of 2)
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 P0117, P0118 or P0380 set? —
Refer to Applicable DTC Go to Step 3
3 Notice:
If no glow indicator lamp is equipped, skip
to Step 3.
1. Verify whether the instrument panel (IP) cluster is operational.
2. Perform the Glow Plug Lamp Control with a scan tool.
3. Command the lamp ON and OFF.
Does the glow indicator lamp turn ON and OFF
with each command? —
Go to Step 4 Go to 2 of 2 Step 1
4 1. Turn OFF the ignition.
2. Make sure the metal bus bar that connects switched battery voltage supply terminal (E-
49) and all glow plugs is secured tightly.
3. Turn ON the ignition, with the engine OFF
4. Connect a test lamp between the metal bus bar (glow plug power supply E-49 terminal)
and a known good ground.
5. Perform the Glow Relay Control with a scan tool.
6. Command the relay ON while observing the test lamp.
Does the test lamp turn ON only when commanded
ON? —
Go to Step 5 Go to Step 6

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ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-307
51. Turn OFF the ignition.
2. Remove the metal bus bar from the glow plugs.
3. Measure resistance of each glow plug between the glow plug terminals and a known
good ground. Make sure to record all
measurements and take them quickly as to
not allow engine temperature changes
between measurements.
Are the resistances within the specified value each
other? 1
Ω
System OK Go to Step 16
6 1. Turn OFF the ignition.
2. Replace the glow relay with the starter relay or replace with a known good relay.
3. Turn ON the ignition, with the engine OFF.
4. Connect a test lamp between the metal bus bar (glow plug power supply E-49 connector)
and a known good ground.
5. Perform the Glow Relay Control with a scan tool.
6. Command the relay ON while observing the test lamp.
Does the test lamp turn ON only when commanded
ON? —
Go to Step 14 Go to Step 7
7 Inspect the Glow (60A) slow blow fuse in the
engine room fuse block.
Is the Glow (60A) slow blow fuse open? —
Go to Step 8 Go to Step 9
8 Replace the Glow (60A) slow blow fuse. If the slow
blow fuse continues to open, repair the short to
ground on a circuit fed by the slow blow fuse or
check for a shorted attached component.
Did you complete the repair? —
Go to Step 17
—
91. Turn OFF the ignition.
2. Remove the glow relay.
3. Probe the battery voltage feed circuit of the relay (pin 4 of X-5) with a test lamp that is
connected to a known good ground.
Does the test lamp illuminate? —
Go to Step 10 Go to Step 11
10 1. Probe the voltage supply circuit of glow plugs
(pin 1 of X-5) with a test lamp that is
connected to a known good ground.
2. Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate? —
Go to Step 13 Go to Step 12
11 Repair the open circuit or high resistance between
the Glow (60A) slow blow fuse and the glow relay
(pin 4 of X-5).
Did you complete the repair? —
Go to Step 17
—
12Repair the open circuit or high resistance between
the glow relay (pin 1 of X-5) and the glow plugs (E-
49 terminal).
Did you complete the repair? —
Go to Step 17
—
Step Action Value(s)Yes No

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6E-308 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Circuit/ System Testing Glow Control System Check (2 of 2)
13Important
: The glow plugs may be burnt out if the
battery voltage supply circuit is shorted to a voltage
source.
Repair the short to battery or ignition voltage
between the glow relay (pin 1 of X-5) and the glow
plugs (E-49 terminal).
Did you complete the repair? —
Go to Step 17
—
141. Remove the glow relay.
2. Inspect for an intermittent and for poor connection on each glow relay terminal.
3. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 17 Go to Step 15
15 Replace the glow relay.
Did you complete the replacement? —
Go to Step 17
—
16Replace the appropriate glow plug.
Did you complete the replacement? —
Go to Step 17—
171. Reconnect all previously disconnected
components, relay, fuse or harness
connector(s).
2. Turn OFF the ignition for 30 seconds.
3. Turn ON the ignition, with the engine OFF.
4. Connect a test lamp between the metal bus bar (glow plug power supply E-49 connector)
and a known good ground.
5. Perform the Glow Relay Control with a scan tool.
6. Command the relay ON while observing the test lamp.
Does the test lamp turn ON only when commanded
ON? —
Go to Step 5 Go to Step 2
Step
Action Value(s)Yes No
Step Action Value(s)Yes No
1 1. Turn OFF the ignition.
2. Inspect the Meter (10A) fuse in cabin fuse block.
Is the Meter (10A) fuse open? —
Go to Step 2 Go to Step 3
2 Replace the Meter (10A) fuse. If the fuse continues
to open, repair the short to ground on one of the
circuits that is fed by the Meter (10A) fuse or
replace the shorted attached component.
Did you complete the repair? —
Go to Step 14
—
31. Turn OFF the ignition.
2. Disconnect the ECM J-2 (C-58) harness connector.
3. Turn ON the ignition, with the engine OFF.
Is the glow indicator lamp OFF? —
Go to Step 4 Go to Step 10

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ISUZU KB P190 2007