Venue Diesel Rough Cold Starts

I have a Venue too, and your symptoms sound familiar. I had similar problems – rough starts, error codes, and poor fuel economy. I didn't initially suspect the PTC heater, but your post makes me think. Was the cabin heat slow to warm up?

Yes, the heat is slow to get going. Did you also experience this with the rough starts and increased fuel consumption? Did you sort it out yourself, or did you take it to a shop?

The slow cabin heating was definitely part of it. I spent ages trying to trace an electrical fault with the HVAC system, but eventually I had the workshop take a look. They confirmed it was a defective electric auxiliary heater, the PTC heater. The mechanic said it was affecting the engine's warm-up cycle, hence the poor running and extra fuel use. Unless you're confident with electrical diagnostics, I'd suggest getting it checked out. Could save you a headache.

Thanks for the insight! It confirms my suspicion. I'll book it in with a local shop to get the PTC heater replaced. They quoted around 350€ for the repair, which seems reasonable. I'll post the solution once it's resolved.