P0384 OBD-II Trouble Code: Glow Plug Control Module Control Circuit High

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P0384 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0384 code

P0384 is a diagnostic trouble code (DTC) for "Glow Plug Control Module Control Circuit High". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $79.99. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$79.99$20.00
Toyota$79.99$20.00
BMW$79.99$20.00
SCHEDULE P0384 DIAGNOSTIC Get a fair and transparent estimate upfront

check engine light

P0384 code definition

The P0384 code is stored when the PCM detects a malfunction in the voltage reading of the glow plug heater circuit – specifically, a reading that is too high. This will often be accompanied by other glow plug circuit codes.

What the P0384 code means

The glow plug system provides the heat that the engine needs to begin combustion in cold temperatures. Glow plugs heat before, during, and after cranking, and the temperature and voltage of the glow plugs is monitored by the ECM. If the voltage reading detected by the ECM is more than 10% higher than the reading recommended by the manufacturer, the PCM will store the P0384 code.

What causes the P0384 code?

Most of the time, a faulty glow plug is to blame for the P0384 code. However, there could be quite a few other causes, including:

  • Faulty glow plug relay
  • Bad glow plug module or timer
  • Loose, corroded, or shorted glow plug circuit electrical connectors
  • Loose, shorted, or open wiring in the glow plug heater circuit
  • Blown fuses, which also indicate an underlying issue elsewhere
  • Open or shorted glow plug harness

What are the symptoms of the P0384 code?

Most vehicle owners will observe a slow start, and possibly even white smoke from the exhaust when the vehicle does start. The engine may be exceedingly loud, and the glow plug indicator lamp may stay on constantly. The code will be stored in the PCM, and the Check Engine lamp will illuminate.

How does a mechanic diagnose the P0384 code?

After an OBD-II scanner detects the P0384 code, a technician should begin with a visual inspection of all the wiring and connectors related to the glow plug heater circuit. Any damaged elements should be replaced, reconnected, or repaired as necessary. They should then clear the code and perform a test drive, checking that the Check Engine light does not reappear.

If the light does reappear, the mechanic can then move on to checking each of the individual glow plug connectors for the proper voltage and ground signals. As the mechanic moves through each potential repair to find the issue, they should be sure to clear the code from the PCM and retest the system after each step. This will ensure that they do not waste time or money repairing things when the issue has already been fixed.

Common mistakes when diagnosing the P0384 code

Most often, the wiring, connectors, and/or the glow plug itself are to blame. However, many technicians report that the glow plug timers and glow plug relays are often replaced when they don’t need to be. Mechanics should be sure to check wiring and commonly at-fault parts before replacing anything.

How serious is the P0384 code?

If the P0384 code is stored in the PCM, the vehicle should be repaired right away – especially if the weather is cold. This issue can cause major issues with the start up and operation of a vehicle.

What repairs can fix the P0384 code?

There are many ways that a technician can address a P0384 code detection. They include:

  • Replacing a faulty glow plug
  • Replacing a faulty glow plug relay
  • Replacing a bad glow plug module or timer
  • Repairing loose, corroded, or shorted glow plug circuit electrical connectors
  • Repairing loose, shorted, or open wiring in the glow plug heater circuit
  • Replacing blown fuses, and searching for and repairing the underlying issue that a blown fuse can indicate
  • Repairing an open or shorted glow plug harness

Additional comments for consideration regarding the P0384 code

While attempting to diagnose and repair the issue behind the P0384 code, it is important to be careful and wear the proper safety gear. Glow plugs get very hot very quickly; within a few seconds, a properly-functioning glow plug will be orange from the heat.

Need help with a P0384 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

P0383
trouble codes
Check Engine Light

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P0384 DIAGNOSTIC
Get a fair and transparent estimate upfront

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.8/5

Number of Reviews

4,255

Rating Summary
3,898
174
45
26
112
3,898
174
45
26
112
Ben

Ben

39 years of experience
1020 reviews
Ben
39 years of experience
Lexus LS430 - Check Engine Light is on - Houston, Texas
I was very pleased with the courtesy and work of Mr. Smith. He was exceptional in explaining and correcting the problem and thereby gained my trustI . I request he be my mechanic in all future service requests. I had a great experience working with Mr. Ben Smith.
Richard

Richard

19 years of experience
203 reviews
Richard
19 years of experience
Ram ProMaster 1500 - Check Engine Light is on - Bonita Springs, Florida
Prompt, polite and personal. Took the time to explain the process and his recommendations. 2 thumbs up
Michael

Michael

23 years of experience
37 reviews
Michael
23 years of experience
Ford F-150 - Check Engine Light is on - Federal Way, Washington
Very helpful and explained everything and what needs to be addressed. I feel informed and confident in Mike’s assessment and look forward to him performing services on my vehicle.
Rigoberto

Rigoberto

9 years of experience
650 reviews
Rigoberto
9 years of experience
Honda Civic - Check Engine Light is on - Chicago, Illinois
Rigoberto came on time & quickly diagnosed the problem- rats chewed thru wiring near the battery. He wasn’t able to fix it himself bc of parts, but gave me recommendations on where to go & how to not have the dealership sell me services that are not needed.

More related articles

How to Get a Louisiana Driver's Permit
s licensing program. The first step in this program is to obtain...
P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...

Related questions

Q: Getting Red Lighting Bolt Warning Light and Check Engine Light

Hi there. Assuming the Check Engine Light and red lightning bolt were on before your vehicle experienced the no start condition. This would indicate a malfunction in the electronic throttle control system. The computer has recognized the fault and stored...

Q: Service park assist is displaying on dash

Hello, and thank you for writing in. Your vehicle is equipped with the Park Assist feature which will help you park in difficult situations. When the computer system detects there is an issue, the warning light illuminates to let you...

Q: EPS light came on

There is a problem with the logic which turns on the EPS dash light for your Forte, which is addressed with Kia Technical Service Bulletin TSB-10044130-2564. Check with your Kia dealer service center for this software update per this TSB....

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 · hi@yourmechanic.com