What P0675 usually means
P0675 indicates cylinder 5 is not receiving normal preheat support. That can be enough to create a longer crank and a rough, smoky first few seconds, especially on engines that already have some age on them or see colder climates. As with other single-cylinder glow plug codes, the right mindset is not just “replace one plug” but “confirm the plug, the feed, and the condition of the full preheat system.”