P0384

Glow Plug Control Module 1 Control Circuit High

Q: Is it safe to drive with P0384?

Yes once the engine is running and warm. The real problem is cold starting — plan to fix it before cold weather, since a diesel can become very hard to start without working glow plugs.

Q: Can I just clear P0384?

It returns while the circuit still reads high. Repair the module or wiring first, then clear and re-test.

Glow plug / diesel starting Generic OBD-II High

What it means

P0384 means the ECM detected an abnormally high voltage on the control circuit for glow plug control module 1. Glow plugs preheat a diesel's combustion chambers for starting, so a fault here — from wiring shorted to voltage, a bad connector, or a failed module — mainly causes hard cold starting, rough cold running, and white exhaust smoke.

High

Can I keep driving? Runs normally once warm; the main effect is hard cold starting, rough cold running, and possible white smoke until the glow plug system is fixed.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

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 (and often the glow-plug/wait-to-start light) on
Hard starting, especially in cold weather
Rough running and white smoke on a cold start
Reduced performance while the engine is cold

Common causes

Most likely first

Faulty glow plug control moduleLikely
Wiring shorted to voltage (high) in the control circuitCommon
Loose or corroded connector at the moduleCommon
One or more failed glow plugsLess often
Failed ECM (rare)Less often

How to diagnose & fix

Work through it in order

Read freeze-frame data and check for companion glow-plug codes.
Inspect the glow plug control module connector and wiring for a short to voltage or corrosion.
Measure the control circuit voltage and compare to spec.
Test the individual glow plugs for correct resistance and replace any that are open.
Replace the glow plug control module if the circuit stays high. Clear and re-test.

FAQ

Quick answers

Is it safe to drive with P0384?+

Yes once the engine is running and warm. The real problem is cold starting — plan to fix it before cold weather, since a diesel can become very hard to start without working glow plugs.

Can I just clear P0384?+

It returns while the circuit still reads high. Repair the module or wiring first, then clear and re-test.

Read & clear P0384 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