P0671 OBD-II Trouble Code: Cylinder 1 Glow Plug Circuit

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

SCHEDULE P0671 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0671 code

P0671 is a diagnostic trouble code (DTC) for "Cylinder 1 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 for $70.00. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $30.00 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$70.00$30.00
Toyota$70.00$30.00
BMW$70.00$30.00
SCHEDULE P0671 DIAGNOSTIC Get a fair and transparent estimate upfront

Check Engine Light

P0671 code definition

The P0671 code indicates that the PCM has detected an abnormal voltage reading from the glow plug circuit in cylinder 1.

What the P0671 code means

Diesel engines require glow plugs to heat cylinders before and during the ignition process. Each cylinder has a glow plug, which uses battery voltage to heat up. The PCM controls the activation of the glow plug circuit, and monitors the activity with voltage readings. If the voltage reading does not match the manufacturer’s specifications, it is likely that the glow plug is not working properly to heat the engine. In this case, the PCM will store the P0671 code.

What causes the P0671 code?

There are many things that can cause the P0671 code. These include:

  • Faulty glow plug
  • Faulty glow plug relay
  • Faulty glow plug timer
  • Faulty electrical components within the glow plug circuit
  • Blown fuses, which could indicate a larger issue

What are the symptoms of the P0671 code?

Most of the time, the vehicle’s owner will notice that the vehicle is taking longer to start, and that the glow plug indicator light never deactivates, or stays on for longer than normal. White smoke may be observed upon start-up; the engine may be considerably louder than normal during start-up; the engine may misfire; and the Check Engine lamp will be illuminated.

How does a mechanic diagnose the P0671 code?

After an OBD-II scanner detects the P0671 code, a technician should begin with a visual inspection of the electrical components, repairing or replacing any damaged components as necessary. After this, and any other repair process, the PCM should be cleared, and the system should be retested, to find out if the repair solved the issue.

If the electrical components were not to blame, the mechanic will begin checking the glow plug connector, the glow plug itself, and fuses, for proper function. Activating the glow plug heater after checking each of these repairs will show the mechanic if there is a short in the circuitry, or if the parts themselves were to blame.

Common mistakes when diagnosing the P0671 code

While glow plugs themselves, and the electrical components within the glow plug circuit, are often to blame for the P0671 code, many technicians report that glow plug timers and relays are frequently replaced without checking the electrical components and glow plugs.

How serious is the P0671 code?

The P0671 code represents a serious issue that affects the drivability of the vehicle. If left unrepaired, the vehicle may not start properly, or at all, in the future.

What repairs can fix the P0671 code?

There are many ways that a technician can address a P0671 code detection. They include:

  • Replacing faulty glow plug
  • Replacing faulty glow plug relay
  • Replacing faulty glow plug timer
  • Replacing or repairing faulty electrical components within the glow plug circuit
  • Replacing blown fuses

Additional comments for consideration regarding the P0671 code

When repairing any issue related to the glow plugs, safety is very important. When activated, glow plugs become extremely hot. Technicians should exercise caution when testing glow plugs for proper functionality.

Need help with a P0671 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.

P0671
trouble codes
Check Engine Light

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

SCHEDULE P0671 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

4.5/5

Number of Reviews

3,788

Rating Summary
3,460
163
43
24
98
3,460
163
43
24
98

Milton

34 years of experience
154 reviews
Milton
34 years of experience
Good
2009 KIA RIO - CHECK ENGINE LIGHT IS ON - LAS VEGAS, NEVADA

Michael

22 years of experience
181 reviews
Michael
22 years of experience
Great Job as usual!
2006 CHRYSLER 300 - CHECK ENGINE LIGHT IS ON - CHARLOTTE, NORTH CAROLINA

James

27 years of experience
331 reviews
James
27 years of experience
Kind, courteous and extremely knowledgeable. Very fair priced . On time! Thanks James!
2005 DODGE RAM 1500 - CHECK ENGINE LIGHT IS ON - WINDERMERE, FLORIDA

Michael

13 years of experience
403 reviews
Michael
13 years of experience

2009 NISSAN ALTIMA - CHECK ENGINE LIGHT IS ON - ALPHARETTA, GEORGIA

More related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0222 OBD-II Trouble Code: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
P0222 code definition Throttle/Pedal Position Switch/Sensor B Circuit Low Input What the P0222...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...

Related questions

Q: Getting error codes P0599 and P0171. Ive cleaned the O2 sensors but have no idea where to go from here.

Hello. Code P0599 is the code for an issue with the thermostat heater control circuit, while P0171 is for a lean condition on bank 1. P0599 is set when the computer detects that there is an issue with the electronically...

Q: Land rover over heating and check engine light flashing

This is a result of your engine overheating which may be caused by a faulty thermostat. When this is stuck closed, this does not allow the coolant to flow through the motor properly. This may also cause the coolant to...

Q: My car has the OBD-II codes P0030 and P0135 for the heater control circuit and sensor. Where is this sensor located?

This is a code that pertains to the heater side of your oxygen sensor. The heater is required to raise the temperature of the sensor so that it can operate properly. Simply unplugging relays/fuses will not keep the code from...

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