Modern diesel glow systems switch each glow plug through its own power semiconductor (in a glow plug module or the engine module), so current and faults can be measured per plug. CARB requires glow plugs to be checked for current and voltage drop and, since model year 2010, a single faulty plug to be detected and named. P0680 means the load circuit of the cylinder 10 glow plug is open while glowing. No manufacturer document available to us uses this code – the only diesel with more than eight cylinders sold under OBD II in the US, VW's Touareg V10 TDI (2006–07), is documented only with a general glow plug tip naming no codes. The description therefore follows cylinders 1–8 (GM 200 kΩ, Ford below 1 A). A weak battery strains the glow system on such engines.
Low severity. Can I keep driving?You can keep driving, although cold starts will be harder. Avoid cranking the starter repeatedly on cold days.
Cylinder 10 is numbered according to the manufacturer: check your engine's manual before working on it.
Symptoms
- Check engine light (GM also glow plug lamp)
- Harder cold start in low temperatures
- Rough idle and white smoke after a cold start
- Often no symptoms when warm
Most likely causes
- Glow plug cylinder 10 burnt out (element open)
- Plug connector loose or corroded, terminal nut loose, wire broken
- Glow module supply or ground (several cylinder codes at once)
- Glow module or driver faulty, or software (GM bulletins)
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It affects emissions.
What each character of P0680 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 6: Control modules and outputs
- 80: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0680?
You can keep driving, although cold starts will be harder. Avoid cranking the starter repeatedly on cold days.
What causes code P0680?
The most common causes are: glow plug cylinder 10 burnt out (element open); plug connector loose or corroded, terminal nut loose, wire broken; glow module supply or ground (several cylinder codes at once).
Related codes
- P069CCylinder 10 Glow Plug Control Circuit Low
- P069DCylinder 10 Glow Plug Control Circuit High
- P06C2Cylinder 10 Glow Plug Circuit Range/Performance
- P06CECylinder 10 Glow Plug Incorrect
- P0670Glow Plug Control Module 1 Control Circuit/Open
- P06F5Glow Plug Control Module 2
Sources
- law.cornell.edu: 13 CCR 1968.2
- static.nhtsa.gov: MC 10070763 3639
- fordservicecontent.com: obd summary diesel 2023
- gsi.ext.gm.com: 18OBDG04 Engine Diagnostics
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.