P0672 Cylinder 2 Glow Plug Circuit

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

SCHEDULE P0672 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0672 code

P0672 is a diagnostic trouble code (DTC) for "Cylinder 2 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 P0672 DIAGNOSTIC Get a fair and transparent estimate upfront

P0672 code definition

The P0672 code is an OBD-II generic code indicating a problem with the cylinder 2 glow plug circuit.

What the P0672 code means

P0672 applies to diesel vehicles and it means that the glow plug in cylinder #2 has failed to produce the high level of heat required to perform a cold start in a diesel engine. All diesels devices to heat the cylinders enough to ignite the fuel when the engine is cold, and this code identifies the #2 glow plug circuit as the problem.

What causes the P0672 code?

You may see this code for several reasons:

  • There is a fault in the #2 cylinder glow plug.
  • There are damages in the wiring connector.
  • There is an open or shorted circuit in the glow plug.
  • The control module for the glow plugs is faulty.

What are the symptoms of the P0672 code?

Because the job of the glow plug is to help the diesel engine to turn over in cold weather, the symptoms are often very obvious. However, with a single faulty plug, you may see only a "check engine" light and minimal signs of a problem. In fact, most diesel engines can start with a single faulty plug. When temperatures are below freezing, though, the symptoms may include:

  • Hard starts on engines due to a cold block and failed glow plug.
  • No start conditions.
  • Inadequate power until the engine is fully heated.
  • The engine hesitates when attempting to accelerate.
  • Engine is missing or skipping in cold weather.
  • The pre-heat light continues to remain lit and does not shut off when using the vehicle.

How does a mechanic diagnose the P0672 code?

Mechanics will need to use their DVOM (digital volt ohm meter) to perform the diagnostic tests. Begin by disconnecting wiring to the #2 cylinder glow plug, and placing the DVOM on ohms before touching the red lead to the glow plugs empty terminal and grounding the black lead. The range must be .5 to 2.0 ohms. Next, the mechanic must consider resistance in the glow plug wire and the relay buss bar on the valve cover. This is done by placing the red lead to the buss bar number one wire and the black to the side of the glow plug. The same range of .5 to 2.0 ohms is needed. If it is too high, replace your lead wired to the plug from the buss bar.

Reconnect the wires and visually examine for any signs of cracks or failed insulation. Test with code reader connected to the OBD by turning the key, leaving the engine off and clearing the codes.

Common mistakes when diagnosing the P0672 code

It is not advisable to replace any of the glow plug timers and relays before properly diagnosing the connections. Failing to test wiring and connectors, as well as the glow plugs, easily causes mistakes in the diagnostic process.

How serious is the P0672 code?

The P0672 code will not, usually, prevent a vehicle from starting. If it is only one bad plug, the engine can continue to start. However, over time and changing temperature, the engine may become more and more difficult to start if sitting in cold weather, and this issue can cause a loss in power and acceleration.

What repairs can fix the P0672 code?

The most common repairs needed to fix the P0672 code include:

  • Validating the code with a code scanner, resetting codes and road testing the vehicle. If the code reappears, the next step is to do a visual inspection of the wiring.
  • Remove and test individual plugs as explained in diagnostics, then move on to testing fuses with the glow plug heater activated to reveal if they break down when under load. Replace fuses as needed and activate the heater. If fuses blow, look at the system circuitry for the heater.
  • Alternately, you may have to test the plug relay or module according to the manufacturer's specs. Replacing relays and wires as needed.
  • Retesting can indicate normal system functions, meaning that the final repair may be to test circuit resistance between the PCM and the plug module, but PCM issues are rare.

Additional comments for consideration regarding the P0672 code

Voltage in the system exceeding 10% of that suggested by a vehicle's manufacturer will typically cause this code to be stored in the system, and for a check engine light to illuminate.

Need help with a P0672 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 1-800-701-6220.

trouble codes
P0672
Check Engine Light

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

SCHEDULE P0672 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

4,810

Rating Summary
4,424
187
47
28
124
4,424
187
47
28
124

Joel

19 years of experience
741 reviews
Joel
19 years of experience
Acura RL - Check Engine Light is on - Jacksonville, Florida
very knowledgeable and precise. able to fix electrical issues in my car. Right on time for the appointment.

Christopher

15 years of experience
41 reviews
Christopher
15 years of experience
Honda Accord - Check Engine Light is on - Fairburn, Georgia
Christopher was excellent! He explained everything in detail to make sure I understood. He was professional and provided me with the next course of actions to resolve my care issues. I'm glad he was sent to service my car.

Alexander

18 years of experience
58 reviews
Alexander
18 years of experience
Saab 9-7x - Check Engine Light is on - Kissimmee, Florida
He was very friendly and very helpful . I felt like it was being around a close friend , also gave me so very good advice on my car & future advice about it . Highly recommend mechanic, would use his services again .

Matthew

31 years of experience
639 reviews
Matthew
31 years of experience
Jeep Patriot - Check Engine Light is on - Norfolk, Virginia
Matthew was on time which was a relief, he is very knowledgeable and was easy to understand what was wrong and what was being done. I am recommending to friends and family due to the great experience Matthew gave me. Extremely professional 10/10

More related articles

Related questions

Vehicle Service Light

If you are referring to the check engine light on your vehicle occasionally the cause of it illuminating is the gas cap is loose. If the rubber seal on the gas cap is intact and the cap is tight, all...

Camshaft Position Sensor (Bank 1)

Your description says bank 1 and the lower text says bank 2. It looks like there are 2 exhaust camshaft position sensors on the vehicle and it could be possible you replaced the wrong one. Consider hiring one of our...

check engine light code p0068

The definition for the code P0068 is throttle body airflow performance. A few more things will have to be checked as this code can come from a failing sensor that is offering the computer improper signals. Consider hiring one of...

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