P0672 GMC Code - Cylinder 2 Glow Plug Circuit Fault
Quick Answer
n the diesel engine, air alone is compressed in the cylinder. Common causes include Faulty cylinder #2 glow plug, Cylinder #2 glow plug harness is open or shorted, Cylinder #2 glow plug circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0672 GMC indicates Cylinder 2 Glow Plug Circuit Fault.
- Common causes
- Common causes include Faulty cylinder #2 glow plug, Cylinder #2 glow plug harness is open or shorted, Cylinder #2 glow plug circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P0672 GMC Description
Control of the glow plugs is accomplished by the Glow Plug Control Module. The nominal voltage for the glow plugs is 5.4 volts. When the ignition is turned On, the Glow Plug Control Module applies 7.2 V for 2.2 s, then 5.7 V for 0.8 s, and then 5.4 V until 1200°C (2192°F) is reached. The maximum voltage of the system is 10 V. While the engine is running the voltage will vary between 4.7 - 10 V when in closed loop control to maintain a glow plug temperature that ranges from 1150° - 1180°C (2102° - 2156°F). The temperature and the power consumption are controlled between the Engine Control Module (ECM) and the Glow Plug Control Module within a wide range to suit the engine's pre-heating requirements. Each glow plug is energized individually. This capability yields more optimum heat times for the glow plugs, thus pre - glow times can be kept to a minimum for a short wait to crank times and maximum glow plug durability.
What are the Possible Causes of the DTC P0672 GMC?
- Faulty cylinder #2 glow plug
- Cylinder #2 glow plug harness is open or shorted
- Cylinder #2 glow plug circuit poor electrical connection
- Faulty Glow Plug Control Module (GPCM)
How to Fix the DTC P0672 GMC?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0672 GMC code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
Need more information about the P0672 GMC code?
Need more information on how to fix the P0672 GMC code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P0672 GMC code diagnosed by a professional: Find a repair shop in your area
Information for Specific GMC Models
- P0672 2014 GMC Sierra — Cylinder 2 Glow Plug Circuit Fault
- P0672 2015 GMC Sierra — Cylinder 2 Glow Plug Circuit Fault
- P0672 2016 GMC Sierra — Cylinder 2 Glow Plug Circuit Fault
- P0672 2017 GMC Sierra — Cylinder 2 Glow Plug Circuit Fault
- P0672 2018 GMC Sierra — Cylinder 2 Glow Plug Circuit Fault
Frequently Asked Questions about P0672 GMC Code
What does OBDII code P0672 mean on a GMC?
Code P0672 indicates a fault in the glow plug circuit for cylinder 2. The glow plug may not be heating properly, which can affect cold starts.
What are common symptoms of P0672 in a GMC?
Symptoms include hard starting in cold weather, rough idle, reduced engine performance, and an illuminated check engine light.
What causes the P0672 code on a GMC?
Causes may include a faulty glow plug, damaged glow plug wiring, a defective glow plug control module, or poor electrical connections in the circuit.
Can I drive my GMC with a P0672 code?
Driving with a P0672 code is generally safe in warm weather but may cause starting issues in cold temperatures. It's best to address the issue promptly.
How do I diagnose the P0672 code on a GMC?
Start by inspecting the glow plug for cylinder 2, checking for physical damage or corrosion. Test the glow plug with a multimeter and inspect the wiring and connections.
How do I fix the P0672 code on my GMC?
Repairs may include replacing the glow plug for cylinder 2, repairing damaged wiring, cleaning corroded connections, or replacing the glow plug control module if necessary.
How much does it cost to repair P0672 on a GMC?
The cost varies but typically ranges from $50 to $200 for parts and labor, depending on whether just the glow plug or additional components need replacement.
What tools are needed to fix the P0672 code?
Common tools include a multimeter for testing the glow plug, hand tools for removing and replacing parts, and possibly a scan tool to clear the code after repairs.
What happens if I ignore the P0672 code on my GMC?
Ignoring P0672 can lead to harder cold starts, increased fuel consumption, and potential damage to other components in the glow plug system over time.
Is P0672 specific to GMC vehicles?
No, P0672 is a generic OBDII code that applies to all diesel vehicles, but the exact repair steps may vary depending on the make and model.
Discuss the causes and fixes for P0672 GMC OBDII Code
-
Glow plug - Removed and replaced one side, one. Today engine light back on.
Code P0672 GMC
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
