Isuzu N-Series. Manual - part 687

6E-170    Engine Control System (4HK1) 

4

1.

Turn OFF the ignition.

2.

Disconnect the CMP sensor harness
connector.

3.

Inspect for an intermittent and for poor
connections at the harness connector of the
CMP sensor (pins 1, 2 and 3 of E-112
connector).

4.

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 9

Go to Step 5

5

1.

Turn OFF the ignition.

2.

Disconnect the engine control module (ECM)
harness connector.

3.

Inspect for an intermittent and for a poor
connection on these CMP sensor circuit at the
harness connector of the ECM (pins 98, 99
and 100 of E-111 connector).

Did you find and correct the condition?

—

Go to Step 9

Go to Step 6

6

1.

Remove the CMP sensor. Refer to Camshaft
Position (CMP) Sensor Replacement in this
section.

2.

Visually inspect the CMP sensor for the
following conditions:

• Physical damage
• Loose or improper installation

3.

The following conditions may cause this DTC
to set:

• Excessive air gap between the CMP

sensor and the camshaft gear surface
(sensor rotor)

• Electromagnetic interference in the CMP

sensor circuits

• Foreign material passing between the

CMP sensor and the camshaft gear
surface (sensor rotor)

Did you find and correct the condition?

—

Go to Step 9

Go to Step 7

7

Inspect the camshaft gear surface (CMP sensor
rotor) for physical damage.

Did you find and correct the condition?

—

Go to Step 9

Go to Step 8

8

Replace the CMP sensor. Refer to Camshaft
Position (CMP) Sensor Replacement in this
section.

Did you complete the replacement?

—

Go to Step 9

—

9

1.

Reconnect all previously disconnected
harness connector(s).

2.

Clear the DTCs with the Tech 2.

3.

Turn OFF the ignition for 30 seconds.

4.

Start the engine. If engine does not start,
crank over the engine for 10 seconds.

Did the DTC fail this ignition?

—

Go to Step 2

Go to Step 10

10

Observe the DTC Information with the Tech 2.

Are there any DTCs that you have not diagnosed?

—

Go to Diagnostic 

Trouble Code (DTC) 

List

System OK

Step

Action

Value(s)

Yes

No

 Engine Control System (4HK1)    6E-171

P0380 (Flash Code 66)

Circuit Description
The engine control module (ECM) controls the glow
relay which supplies power to the glow plugs based on
engine coolant temperature. In the after glow phase,
the glow indicator light is not illuminated but glow plugs
remain active for a certain period. If the ECM detects
an open circuit or short circuit on the glow relay control
circuit, this DTC will set.

Condition for Running the DTC

• The ignition switch is ON.
• The battery voltage is between 16 – 32 volts.

Condition for Setting the DTC
Either of following condition is met:

• The ECM detects a low voltage condition on the

glow relay control circuit when the relay is
commanded OFF for longer than 5 seconds.

• The ECM detects a high voltage condition on the

glow relay control circuit when the relay is
commanded ON for longer than 5 seconds.

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 key is

cycled after a current DTC clears.

• A current DTC clears when the diagnostic runs and

does not fail at next driving cycle.

• A history DTC clears after 20 consecutive driving

cycles without a fault. Or clear with the Tech 2 or
accelerator pedal operation.

Diagnostic Aid

• If an intermittent condition is suspected, refer to

Intermittent Conditions in this section.

Test Description
The numbers below refers to the step number on the
diagnostic table.
2. Listen for an audible click when the glow relay
operates. Command both the ON and OFF states.
6. Tests if ground is constantly being applied to the
glow relay.

DTC P0380 (Flash Code 66)
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 Tech 2.

2.

Turn ON the ignition, with the engine OFF.

3.

Perform the Glow Relay Test with the Tech 2.

4.

Command the Glow Relay ON with the Tech
2.

Does the glow relay click when commanded ON
with the Tech 2?

—

Go to Step 3

Go to Step 4

3

1.

Turn OFF the ignition for 30 seconds.

2.

Turn ON the ignition, with the engine OFF.

3.

Disconnect the engine coolant temperature
(ECT) sensor harness connector in order to
gain glow ON time long enough.

4.

Turn ON the ignition for 30 seconds while
observing the Diagnostic Trouble Code (DTC)
Information with the Tech 2.

Does the DTC fail this ignition?

—

Go to Step 11

Go to Diagnostic 

Aids

6E-172    Engine Control System (4HK1) 

4

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.

Perform the Glow Relay Test with the Tech 2.

5.

Command the Glow Relay ON with the Tech
2.

Does the glow relay click when commanded ON
with the Tech 2?

—

Go to Step 8

Go to Step 5

5

1.

Turn OFF the ignition.

2.

Remove the glow relay.

3.

Turn ON the ignition, with the engine OFF.

4.

Probe the voltage feed circuit of the glow relay
coil side (pin 4 of X-20 connector) with a test
lamp that is connected to a known good
ground.

Does the test lamp illuminate?

—

Go to Step 6

Go to Step 7

6

1.

Test the control circuit of glow relay between
the engine control module (ECM) (pin 10 of J-
191 connector) and the glow relay (pin 5 of X-
20 connector) for the following conditions:

• An open circuit
• A short to ground
• A short to battery or ignition voltage

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 12

Go to Step 9

7

Repair the open circuit or high resistance on the
voltage feed circuit between the ENG (10A) fuse
and the glow relay coil side (pin 4 of X-20
connector). Check the ENG (IG) (10 A) fuse first.

Did you complete the repair?

—

Go to Step 12

—

8

1.

Turn OFF the ignition.

2.

Remove the glow relay.

3.

Inspect for an intermittent and for a poor
connection on each glow plug relay terminal.

4.

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 a poor
connection on the glow relay circuit at the
harness connector of the ECM (pin 10 of J-
191 connector).

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 glow relay.

Did you complete the replacement?

—

Go to Step 12

—

Step

Action

Value(s)

Yes

No

 Engine Control System (4HK1)    6E-173

11

Important:
Replacement ECM must be programmed.

Replace the ECM. Refer to Engine Control Module
(ECM) Replacement / Fuel Injector ID Code Data
Programming in this section.

Did you complete the replacement?

—

Go to Step 12

—

12

1.

Reconnect all previously disconnected fuse,
relay or harness connector(s).

2.

Clear the DTCs with the Tech 2.

3.

Turn OFF the ignition for 30 seconds.

4.

Disconnect the ECT sensor harness
connector in order to gain glow ON time long
enough.

5.

Turn ON the ignition for 30 seconds while
observing the DTC Information with the Tech
2.

Did the DTC fail this ignition?

—

Go to Step 2

Go to Step 13

13

Observe the DTC Information with the Tech 2.

Are there any DTCs that you have not diagnosed?

—

Go to Diagnostic 

Trouble Code (DTC) 

List

System OK

Step

Action

Value(s)

Yes

No