P0673 OBD-II Trouble Code: Cylinder 3 Glow Plug Circuit

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

SCHEDULE P0673 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0673 code

P0673 is a diagnostic trouble code (DTC) for "Cylinder 3 Glow Plug Circuit". 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. 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$20.00
Toyota$20.00
BMW$20.00
SCHEDULE P0673 DIAGNOSTIC Get a fair and transparent estimate upfront

P0673 Code Definition

The P0673 code is a generic powertrain code related to issues with a computer output circuit. In this case, it means that an issues has been noted with the glow plug circuit in cylinder 3 of your engine.

Codes related to the P0673 include:

What the P0673 Code Means

A glow plug is a device utilized in diesel engines to heat a cylinder head when starting up a cold engine. The diesel engine uses the high level of heat through compression, which quickly ignites the fuel. Each cylinder of the engine has a glow plug to heat the cylinder head.

When a P0673 trouble code is stored, it means that the system reference voltage allowed by the vehicle’s engine control module (ECM) has exceeded 10% of preset variance parameters.

While a glow plug will typically last 100,000 miles, they can fail before that mileage. The glow plug is installed in the cylinder head as close as possible to the cylinders combustion point. Using oil and transmission sensors, the ECM will determine if the glow plug is needed for ignition and grounds the glow plug timer module, which grounds the glow plug relay. Typically, a P0673 code means the glow plug has failed to heat up and could be damaged.

What Causes the P0673 Code?

Several problems may cause a P0673 code including:

  • Damaged or defective glow plug in cylinder 3
  • Damaged or defective glow plug module or timer
  • Damaged or defective glow plug relay
  • Blown fuse(s)
  • Damaged, defective, corroded or loose wiring, harnesses, and related connectors n the glow plug circuit

What are the Symptoms of the P0673 Code?

Symptoms of a P0673 code may include:

  • An illuminated warning or check engine light
  • Vehicle may not start up as quickly as normal
  • Vehicle may not start at all in cold weather
  • Glow plug indicator light may not illuminate or illuminate longer than normal
  • Additional white smoke when the vehicle starts
  • Vehicle may have a loss in power
  • Abnormal, loud noise from the engine
  • The engine may misfire

How Does a Mechanic Diagnose the P0673 Code?

A mechanic may use several methods to diagnose a P0673 trouble code, including:

  • Test glow plug timer, relay, or module

  • Utilize an OBD-II scanner to check for a stored P0673 trouble code

  • Check if glow plug will “warm” with battery voltage or test with digital volt/ohmmeter

  • Test all system fuses to ensure they are in working order with the glow plug heater activated

  • Test the glow plug after disconnecting it from cylinder 3 and check ground and resistance

  • Visually inspect wiring, harnesses, and connectors related to the glow plug circuit for damage

Common Mistakes when Diagnosing the P0673 Code

If blown fuses are located, there may be an underlying problem beyond what a P0673 code holds, so it is always recommended to repair stored codes in the order in which they appear. Often, glow plug timers and relays are replaced before wiring and the glow plug itself is tested, which can lead to misdiagnosis and unnecessary repairs.

How Serious is the P0673 Code?

Because a vehicle’s safe driving operation may be impacted due to faults that store a P0673 code, this code is considered a potentially serious code. When this code appears, it is recommended to immediately take your vehicle to your local service center or mechanic for repair and diagnosis.

What Repairs can Fix the P0673 Code?

Several repairs can fix a P0673 trouble code and include:

Additional Comments for Consideration Regarding the P0673 Code

Often, additional glow plug circuit codes will accompany a P0673, so it is recommended to do a full diagnosis and note all trouble codes that may be stored to fully repair the issue.

Need Help with a P0673 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.

trouble codes
Check Engine Light
P0673

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

SCHEDULE P0673 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

4,743

Rating Summary
4,361
185
47
28
122
4,361
185
47
28
122

Oreste

12 years of experience
108 reviews
Oreste
12 years of experience
Nissan Altima - Check Engine Light is on - Hialeah, Florida
Showed up quick, and went straight to inspecting a brake light on the dash issue. He found the issue, fixed it, and showed me exactly what was wrong. Thank you!

Daniel

9 years of experience
58 reviews
Daniel
9 years of experience
Honda Fit - Check Engine Light is on - Chicago, Illinois
Told me everything I needed to know and switch out after the inspection. So, I scheduled another service the next day for all the fixes, or fluid maintenance.

Patrick

31 years of experience
1032 reviews
Patrick
31 years of experience
Hyundai Santa Fe - Check Engine Light is on - Austin, Texas
Even after working on my car, he took the time to explain what he did, the parts, and any next steps. Very knowledgeable!

Joe

12 years of experience
22 reviews
Joe
12 years of experience
Toyota 4Runner - Check Engine Light is on - Sacramento, California
Joe was very thorough in his inspections, and his knowledge & experience was clear in his explanations of what was wrong with my car. I really appreciated his recommendations, and the fact that he worked so efficiently that it cut down on time... I would definitely book with him again.

More related articles

How Long Does a Vacuum Brake Booster Check Valve Last?
The The braking system on your car requires a lot of pressure. The vacuum booster is one of the main sources of this pressure. This booster will take the pressure that is put on the brake pedal and minimize it...
How Long Does a Throttle Return Spring Last?
Not Not all vehicles on the road feature an electronic throttle control (ETC), which is also called drive-by-wire. For vehicles that don't offer this system, they have a throttle cable instead that is attached to the accelerator pedal, and runs...
Rules of the Road For Iowa Drivers
Driving Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in your own state, that does not mean you know them in all...

Related questions

Check Engine Light does not come on even though there are trouble codes present

The pink/light green wire in ECM pin 2 on the connector will ground the wire internally to the ECM to turn on the Check Engine Light. You could test the wire with the key on and it should have battery...

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...

Getting error code P0673

Taking your car on a road trip should be fine. This code that you are getting is for a glow plug issue. These are typically only used to warm the car up before starting it. Once you get back you...

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