What does P0673 mean?
Glow plugs heat the combustion chamber so a diesel can start when cold. This code covers the cylinder 3 glow plug.
The computer tried to control the part and saw an electrical fault, usually an open circuit.
Codes are a starting point. They tell you which test failed, not which part to replace. Check for other stored codes and fix those in a sensible order.
Symptoms
- Hard starting when cold
- White smoke and rough running at cold start
- Wait-to-start light behavior changes
- Check engine light
Common causes
- Open circuit in the solenoid or its wiring
- Unplugged or corroded connector
- Blown fuse feeding the component
- Failed component
How to diagnose P0673
- Check the fuse that feeds the component.
- Measure the component's resistance and compare it with the service spec.
- Check for power at the connector with the key on, and for a broken control wire back to the computer.
- Measure each glow plug's resistance (healthy plugs are usually under about 2 ohms).
- Check for voltage at the plugs during the glow cycle.
How to fix it
- Replace the bad glow plug(s)
- Replace the glow plug module or relay
- Repair the harness
Estimated repair cost
Likely repairs for P0673 run from about $100 to $1,200, depending on the cause.
| Repair | Typical range (parts + labor) |
|---|---|
| Diagnostic fee (scan + testing) | $100 - $200 |
| Glow plug replacement (one) | $100 - $400 |
| Glow plug set (V8 diesel) | $400 - $1,200 |
| Glow plug control module/relay | $150 - $600 |
These are rough US estimates for an independent shop in 2026, based on typical parts prices and standard labor times. Dealers, big trucks, luxury brands and high-cost areas often run higher. They are not quotes. Use the repair cost estimator to adjust for your vehicle.
How serious is P0673?
Low severity
Safe to drive in warm weather. In winter it can leave you unable to start.
P0673 FAQ
What does P0673 mean?
P0673 stands for "Cylinder 3 Glow Plug Circuit". Glow plugs heat the combustion chamber so a diesel can start when cold.
Can I drive with a P0673 code?
Safe to drive in warm weather. In winter it can leave you unable to start.
How much does it cost to fix P0673?
It depends on the cause. The likely repairs for P0673 range from about $100 to $1,200 at an independent shop in the US, plus a diagnostic fee of roughly $100-$200. These are rough estimates; dealer prices and some vehicles run higher.
What is the most common cause of P0673?
The most common causes are: open circuit in the solenoid or its wiring; unplugged or corroded connector; blown fuse feeding the component.