Coolant Level Issue Mercedes B Klasse Hybrid

I had a similar problem with my B Klasse. The coolant level was dropping, and the check engine light kept appearing. Check the radiator cap first. Sometimes it doesn't seal properly, which can cause coolant to evaporate. Then, inspect your radiator hoses for any signs of a coolant leak.

Thanks for your reply. Where exactly are these radiator hoses located? Also, how can I check the radiator cap to confirm that it is defective? Is there a specific procedure or something?

The radiator hoses connect the engine to the radiator; trace them to look for dampness or dried coolant residue. As for the radiator cap, inspect the rubber seal for cracks. If that looks fine, consider getting a coolant pressure test done; this is like when a doctor checks your blood pressure. It will show any leaks in the system. I'd advise booking a diagnostic check; it could be something simple, such as a defective cable or plug connection of the component, but it's best to be sure.

Thank you, I appreciate the advice! I took it to the workshop. It was indeed a defective cable/plug connection of the component. Repair cost 95€. All sorted now!