P0381

Glow Plug/Heater Indicator Control Circuit/Open

Glow plug indicator (diesel) Generic OBD-II High

What it means

P0381 refers to the glow-plug/heater indicator control circuit — the ECM output that drives the glow-plug warning lamp — reading open. On most vehicles this is a lamp/indicator circuit fault, not the glow plugs themselves, so the engine generally still starts and runs; the concern is that the dash may no longer show the glow (wait-to-start) indicator correctly.

High

Can I keep driving? The engine itself normally still starts and runs — this is the glow-plug indicator (warning-lamp) control circuit, not the glow plugs; on a cold diesel just note the indicator may no longer report pre-heat correctly.

Real-world scan data

Seen in

490

scans in the past year

Found in

0.1%

of scans

0.1%

of scans that found faults

Appears alongside · share of P0381 scans

P132Bin 19.8% of scans

P0830in 18.0% of scans

P0113in 15.5% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Glow-plug (wait-to-start) indicator lamp not lighting, or staying on
No reliable pre-glow indication on a cold start
Engine otherwise starts and runs normally

Common causes

Most likely first

Open or broken wiring in the indicator-lamp control circuitLikely
Failed indicator bulb/LED or its driverCommon
Poor or corroded connectorCommon
ECM / glow-control module output fault (rare)Less often

How to diagnose & fix

Work through it in order

Confirm from the factory wiring diagram that this is the indicator circuit, not the glow plugs themselves (that is a separate code).
Inspect the indicator-lamp control wiring and connector for an open.
Test the indicator bulb/LED and its driver.
Check the glow-control module output.
Repair the open circuit, then clear and re-test. If the engine also hard-starts cold, test the glow plugs under their own code.

FAQ

Quick answers

Is it safe to drive with P0381?+

Usually yes — the engine still runs; you may just lose the glow-plug indicator, so on cold mornings allow normal pre-heat time.

Can I just clear P0381?+

You can, but it returns until the open indicator-circuit is repaired.

Read & clear P0381 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX