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