LandCruiser Preheating Lamp and Smoke

Sounds like the preheating system. When the preheating lamp stays on, it's usually a problem in that circuit. Have you checked the cable and plug connections to the preheating control unit? A bad connection there could cause those symptoms, especially the smoke if the engine isn't getting enough preheat. Look for corrosion or damage.

I didn't check the cable and plug connections to the preheating control unit. Where is that located, and what do you mean by 'defective connection'? I'm not very experienced with this.

The preheating control unit is usually in the engine compartment, often near the engine. 'Defective connection' means check for loose, frayed, or corroded wires. Look closely at the plug itself – sometimes the pins inside can get bent or damaged. With the check engine light, it might be best to have a workshop look at it. They can properly diagnose the electrical fault.

You were right! It was a bad cable connector to the preheating control unit. 95€ later, and it's running smoothly again. Thanks!