Isuzu 4HK1 (Tier 3) Fault Code P0381

Fault Code P0381 Glow lamp fault

Item To Be Detected:
Open/short circuit/damage of lamp or harness

Preconditons When DTC is Set:
1) Key switch input voltage is 18 V or more.
2) DTC P0381 is not detected.

DTC Set Condition:
Glow lamp drive indication signal is unmatched with glow lamp monitor signal.

Fault Judgement Period:
When trouble occurs 25 out of 30 samples.

Behavior When Trouble Occurs:
1) Operationality is not affected.
2) Back-up: No backup action

Diagnosis Lamp: ON

Recovery From Failure: N/A

Possible Causes:
1) Looseness or play in the connection of the ECM connector and coupling connector.
2) Short between the QOS indicator lamp control terminal of the ECM and the ground.
3) Looseness or play in the meter, ECM, and coupling connector.
4) Open circuit, short circuit to ground circuit, or high resistance between the fuse nd the QOS indicator lamp.
5) Bad meter.
6) Bad QOS indicator lamp bulb.
7) Bad ECM.