Isuzu KB P190. Manual — part 294

6E-142 Engine Control System (4JH1)

Step Action

Value(s)

Yes

No

6

1. Turn OFF the ignition.
2. Disconnect the engine control module (ECM)

harness connector.

3. Turn ON the ignition, with the engine OFF.
4. Connect a 3-amp fused jumper wire between the

glow indicator lamp control circuit of the ECM
harness connector (pin 43 of C-56 connector)
and a known good ground.

Does the glow indicator lamp illuminate?



Go to Step 11

Go to Step 7

7

1. Turn OFF the ignition.
2. Remove the instrument panel cluster (IPC).
3. Remove the glow indicator bulb from the IPC

(meter assembly).

Is the glow indicator bulb burned out?



Go to Step 15

Go to Step 8

8

1. Disconnect the IPC harness B-24 connector.
2. Connect a test lamp between the voltage feed

circuit of the glow indicator lamp (pin 30 of B-24
connector) and a known good ground.

3. Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate?



Go to Step 9

Go to Step 12

9

1. Turn OFF the ignition.
2. Reconnect the ECM harness connector.
3. Connect a test lamp between the voltage feed

circuit and control circuit of the glow indicator
lamp (pins 6 and 30 of B-24 connector).

4. Turn ON the ignition, with the engine OFF.
5. Perform the Glow Indicator test with the scan

tool.

6. Command the Glow Indicator ON with the scan

tool.

Does the test lamp turn ON when commanded ON
with the scan tool?



Go to Step 14

Go to Step 13

10

1. Test the control circuit of the glow indicator lamp

between the ECM (pin 43 of C-56 connector) and
the IPC (pin 6 of B-24 connector) for a short to
ground.

2. Repair the circuit(s) as necessary.
Did you find and correct the condition?



Go to Step 19

Go to Step 18

11

1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for a poor

connection on the glow indicator lamp control
circuit at the harness connector of the ECM (pin
43 of C-56 connector).

4. Repair the connection(s) as necessary.
Did you find and correct the condition?



Go to Step 19

Go to Step 18

12

Repair the open circuit or high resistance on the
voltage feed circuit of the glow indicator lamp
between the IPC (pin 30 of B-24 connector) and
Meter (15A) fuse (C-14).
Did you complete the repair?



Go to Step 19



13

1. Repair the open circuit or high resistance on the

control circuit of the glow indicator lamp between
the ECM (pin 43 of C-56 connector) and the IPC
(pin 6 of B-24 connector).

2. Repair the circuit(s) as necessary.
Did you find and correct the condition?



Go to Step 19



Engine Control System (4JH1) 6E-143

Step Action

Value(s)

Yes

No

14

1. Turn OFF the ignition.
2. Inspect for an intermittent and for poor

connections on the glow indicator lamp circuits at
the IPC (pins 6 and 30 of B-24 connector).

3. Repair the connection(s) as necessary.
Did you find and correct the condition?



Go to Step 19

Go to Step 16

15

Replace the glow indicator bulb.
Did you complete the replacement?



Go to Step 19



16

Repair or replace the IPC (meter assembly).
Did you complete the repair or replacement?



Go to Step 19



17

1. Turn OFF the ignition for 30 seconds.
2. Turn ON the ignition for 30 seconds, with the

engine OFF.

3. Monitor the DTC Information with the scan tool.
Does the DTC fail this ignition?



Go to Step 18

Go to Diagnostic

Aids

18

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 19



19

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 2

Go to Step 20

20

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

6E-144 Engine Control System (4JH1)

DTC P0381 (Symptom Code 8) (Flash Code 67)

Circuit Description
The glow indicator lamp is located on the instrument
panel cluster (IPC). The glow control system is operated
when the engine coolant temperature is low, which
allows easier engine starting. If the ignition switch is
turned ON when the engine coolant temperature is low,
the engine control module (ECM) illuminates the glow
indicator lamp and turns ON the glow plugs. After a
fixed time passes, the ECM turns OFF the glow
indicator lamp and the glow plugs. The ECM monitors
the glow indicator lamp control circuit for conditions that
are incorrect for the commanded state of the glow
indicator lamp. If the ECM detects a short to battery or
ignition voltage on the glow indicator 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 high voltage condition

on the glow indicator lamp control circuit for longer
than 1 second when the lamp is commanded ON.

Action Taken When the DTC Sets

• The ECM illuminates the malfunction indicator

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

• If an intermittent condition is suspected, refer to

Intermittent Conditions in this section.

Notice:

• The glow indicator lamp is commanded OFF with

the ignition ON and engine OFF when the engine
coolant temperature is reached at 30°C (86°F).

Test Description
The number below refers to the step number on the
diagnostic table.
3. If the control circuit of the glow indicator lamp
between the ECM and the IPC is normal, the control
circuit voltage low DTC P0381 (Symptom Code 4) will
set.

DTC P0381 (Symptom Code 8) (Flash Code 67)
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 ON the ignition, with the engine OFF.
3. Perform the Glow Indicator test with the scan

tool.

4. Command the Glow Indicator ON with the scan

tool.

Does the glow indicator lamp turn ON when
commanded ON with the scan tool?



Go to Diagnostic

Aids

Go to Step 3

3

1. Turn OFF the ignition.
2. Remove the instrument panel cluster (IPC) in

order to disconnect the IPC harness B-24
connector.

3. Disconnect the IPC harness B-24 connector.
4. Turn ON the ignition for 30 seconds, with the

engine OFF.

5. Monitor the Diagnostic Trouble Code (DTC)

Information with the scan tool.

Does DTC P0381 (Symptom Code 4) set, but not
DTC P0381 (Symptom Code 8)?



Go to Step 5

Go to Step 4

Engine Control System (4JH1) 6E-145

Step Action

Value(s)

Yes

No

4

1. Test the control circuit of the glow indicator lamp

between the engine control module (ECM) (pin
43 of C-56 connector) and the IPC (pin 6 of B-24
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 7

Go to Step 6

5

Repair or replace the IPC (meter assembly).
Did you complete the repair or replacement?



Go to Step 7



6

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 7



7

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. Cool down the engine as necessary (allow

engine coolant temperature to cool down at least
25

°C [77°F]).

5. Turn ON the ignition, with the engine OFF.
6. Monitor the DTC Information with the scan tool.
Did the DTC fail this ignition?



Go to Step 2

Go to Step 8

8

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