What Does P0676 Mean?
The PCM has detected a malfunction in the cylinder 6 glow plug circuit on a diesel engine. This applies to 6-cylinder or larger diesel engines. The cylinder 6 glow plug or its wiring is not meeting expected electrical parameters. Without proper pre-heating, cylinder 6 will not fire cleanly during cold starts. The driver may notice marginally harder starting in cold weather and brief white smoke during warm-up.
Common Causes
40%
Failed cylinder 6 glow plug
25%
Corroded or loose bus bar connection at cylinder 6
20%
Wiring fault in cylinder 6 glow plug circuit
10%
Glow plug control module failure on cylinder 6 output
5%
Cylinder 6 glow plug seized due to carbon or corrosion
Diagnostic Steps
1
Disconnect and measure the cylinder 6 glow plug resistance — expected 0.5-2.0 ohms. Compare to readings from all other cylinders.
2
On V6 diesels, cylinder 6 is typically the rearmost cylinder on bank 2. Check if other bank 2 codes are present, suggesting a shared wiring or bus bar issue.
3
Verify voltage at the cylinder 6 bus bar connection during the glow cycle. If no voltage is present, trace the supply wiring back to the glow plug module.
4
Inspect the bus bar connections, paying attention to the last connection in the chain — vibration and thermal cycling cause fatigue and loosening over time.
5
When replacing the glow plug, especially on inline-6 diesels where cylinder 6 is at the rear, ensure adequate access. Some applications require turbocharger or intake removal for access. Use penetrating oil 24 hours before extraction.
Estimated Repair Cost
$60 - $450
Parts + labor, varies by vehicle and location
The PCM has detected a malfunction in the cylinder 6 glow plug circuit on a diesel engine. This applies to 6-cylinder or larger diesel engines. The cylinder 6 glow plug or its wiring is not meeting expected electrical parameters. Without proper pre-heating, cylinder 6 will not fire cleanly during co...
The most common cause of P0676 (Cylinder 6 Glow Plug Circuit) is: Failed cylinder 6 glow plug
Typical repair costs for P0676 range from $60 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
One failed glow plug on a 6-cylinder diesel has a modest impact on cold starting. The engine will run normally once warm. If this code appears alongside other glow plug codes, the cumulative effect on cold starting can be severe. Address before winter.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0676 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Diesel Glow Plug System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
