Seat Ibiza Diesel Preheating Issue

Whoa, that sounds familiar! I had a similar issue with my old Renault Megane, although it was the glow plugs acting up. The preheating lamp stayed on, and the engine light popped up. Is the smoke whitish? With mine, it was like a James Bond smoke screen whenever I accelerated. I'd check all the wiring and connections to that heating module first, like you're planning. Could save you a bundle! Does it start okay even with the light on?

The smoke is blackish, yes it starts, but a bit rough. The light stays on all the time. You mentioned checking the wiring... any specific areas I should focus on with that glow plug issue on your Renault?

Black smoke is not good, but the light isn't either. On my Renault, the connections to the heating module itself were corroded. Basically, the thing wasn't getting the right signal. If you're not comfortable poking around with electrical stuff, maybe a workshop is the best bet. Could be a quick fix, and they can diagnose it properly. Beats guessing and potentially making it worse. I would still recommend you check the connections yourself. It's like checking if the toaster is plugged in before calling an electrician.

Just wanted to say I took the Ibiza to the workshop. It was a defective cable or plug connection to the preheating control unit, like I thought. Repair was 95€. Thanks for the advice!