The P0672 trouble code is a diagnostic trouble code (DTC) that indicates a malfunction in the glow plug circuit of cylinder 2 in diesel engines. Glow plugs are essential components in diesel engines, designed to preheat the combustion chamber for easier starting, especially in cold weather. When the powertrain control module (PCM) detects an issue with the glow plug circuit, it triggers this code, signaling that the glow plug for cylinder 2 is not functioning correctly.
Understanding and addressing the P0672 code is crucial for maintaining optimal engine performance and ensuring reliable starts, particularly in colder climates.
| P0672 Code Meaning | P0672 Code Common Causes |
|---|---|
| Cylinder 2 Glow Plug Circuit/Open | Faulty glow plug in cylinder #2 |
| Glow Plug Circuit Malfunction | Damaged wiring or poor connections |
| Open Circuit Condition | Faulty glow plug control module |
| Electrical Short Circuit | Blown fuses or damaged connectors |
| Insufficient Power Supply to Glow Plug | Corrosion or wear in electrical connections |
Symptoms of P0672 Code
When dealing with the P0672 code, vehicle owners may notice several symptoms that indicate a problem with the glow plug circuit:
- Hard Starting: The engine may struggle to start, particularly in cold weather.
- Check Engine Light: The check engine light will illuminate on the dashboard.
- Reduced Power: There may be a noticeable lack of power until the engine warms up.
- Engine Misfires: The engine may misfire or hesitate during acceleration due to insufficient heat in the combustion chamber.
- No Preheat Indicator: The preheat indicator light may not illuminate or turn off as expected.
Technical Explanation of P0672 Code
The P0672 code specifically refers to issues within the glow plug circuit of cylinder 2. In diesel engines, glow plugs are used to heat the air-fuel mixture before ignition. If the PCM detects that the glow plug for cylinder 2 is not reaching the necessary temperature, it will log this code.
The glow plug circuit consists of several components:
- Glow Plug: Heats up to facilitate combustion.
- Glow Plug Control Module: Manages power distribution to the glow plugs based on engine temperature and other parameters.
- Wiring and Connectors: Provide electrical connections between the PCM, control module, and glow plugs.
If any part of this circuit fails—whether due to a faulty glow plug, damaged wiring, or a malfunctioning control module—the P0672 code will be triggered.
Step-by-Step Diagnosis of P0672 Code
Diagnosing the P0672 code involves several steps to identify the root cause of the issue. Here’s how DIY mechanics can approach this problem:
- Connect an OBD-II Scanner: Use an OBD-II scanner to confirm the presence of the P0672 code and check for any related codes.
- Visual Inspection: Inspect the wiring harness connected to cylinder 2’s glow plug for signs of damage, corrosion, or loose connections.
- Test Glow Plug Resistance:
- Disconnect the glow plug connector.
- Set a multimeter to ohms and measure resistance across the glow plug terminals.
- A healthy glow plug typically shows resistance between 0.5 to 2.0 ohms. If resistance is significantly higher or shows infinite resistance, replace the glow plug.
- Check Glow Plug Control Module:
- Ensure that power and ground are supplied to the control module.
- Inspect for any signs of physical damage or corrosion on connectors.
- If faulty, replace it according to manufacturer specifications.
- Inspect Fuses and Relays: Check relevant fuses and relays associated with the glow plug circuit for continuity and functionality.
- Clear Codes and Test Drive: After repairs, clear any stored codes from the PCM using your scanner and take the vehicle for a test drive to see if symptoms persist.
Solution Methods for P0672 Code
Addressing a P0672 code typically requires one or more of the following solutions:
- Replace Faulty Glow Plug: If testing reveals a defective glow plug, replace it with a new one designed for your vehicle model.
- Repair Wiring Issues: Fix any damaged wires or connectors found during inspection. Ensure all connections are secure and free from corrosion.
- Replace Glow Plug Control Module: If diagnostics indicate a malfunctioning control module, replace it according to manufacturer guidelines.
- Check Electrical Supply: Ensure that there is sufficient voltage reaching the glow plugs from both the control module and battery.
Cost Estimates
The cost associated with diagnosing and repairing a P0672 code can vary significantly based on labor rates and parts prices:
- Glow Plug Replacement: $50 – $150 per glow plug (depending on make/model).
- Glow Plug Control Module Replacement: $100 – $400 (parts only).
- Labor Costs: Typically range from $75 to $150 per hour depending on your location and mechanic expertise.
Overall repair costs can range from $200 to over $600 depending on whether multiple components need replacement.
Warnings and Recommendations
- Always ensure safety by disconnecting battery terminals before working on electrical components.
- If you’re unfamiliar with automotive repairs or diagnostics, consider seeking professional assistance to avoid further complications.
- Regular maintenance checks can help prevent issues with glow plugs and related components before they lead to trouble codes like P0672.
Closing Paragraph
The P0672 trouble code can lead to significant starting issues in diesel engines if not addressed promptly. Understanding its causes, symptoms, and solutions empowers vehicle owners and DIY mechanics alike to tackle these problems effectively. By following proper diagnostic procedures and being aware of potential pitfalls, you can ensure your vehicle remains reliable even in challenging weather conditions.
Frequently Asked Questions About P0672
- What does P0672 mean?
The P0672 code indicates a malfunction in the cylinder 2 glow plug circuit in diesel engines. - How serious is a P0672 code?
A P0672 code can lead to hard starting issues and reduced engine performance, especially in cold weather. - Can I drive my car with a P0672 code?
While it may be possible to drive your car temporarily, it’s advisable to address this issue promptly as it can worsen engine performance. - How much does it cost to fix a P0672 code?
The cost can range from $200 to over $600 depending on parts needed and labor costs. - What are common symptoms of a faulty glow plug?
Common symptoms include hard starting, illuminated check engine light, reduced power during acceleration, and engine misfires. - How do I diagnose a P0672 code?
Diagnosing involves using an OBD-II scanner, inspecting wiring harnesses, testing glow plugs with a multimeter, and checking related components. - Is it safe to replace a glow plug myself?
If you have basic automotive repair skills, you can replace it yourself; otherwise, seek professional help. - What should I do if I can’t find any issues after diagnostics?
If no visible issues are found but symptoms persist, consider consulting a professional mechanic for further evaluation.