Not all warning lights are the end of the world, however. I was aware that my troubles were relatively tame, and there was certainly nothing that would keep my car off the road. Over a period of a few months, where I could find the time in a tight writing schedule, I slowly diagnosed and researched my way through the thicket of problems I was having and managed to fix each in turn. To say I'm chuffed would be an understatement.

How I Fixed All the Irritating Problems With My Cheap Old Mercedes

Defective Lamps

The most annoying problem was the regular warnings of "LAMP DEFECTIVE." They would initially only come on randomly, usually when touching the brake pedal. Eventually, they became a regular warning on every startup. Initial inspections seemed to show all lights functioning, so I was scratching my head for quite some time. Ultimately, though, I realized that while I had working taillights, my brake lights were only functioning on one side.

The problem developed further when I began to get a pair of messages that were more concerning. They seemed to be related; hitting the brakes would sometimes cause the car to throw an error on the "Brake Assist System" (BAS) and the "Acceleration Slip Regulation" system (ASR or traction control). This, too, started as a rare occurrence before becoming a continual problem on every drive.

The fix ended up being tougher than I thought. The BAS and ASR failure was a common one according to forums, usually due to a worn-out brake switch that tells the car's electronics when you're pressing on the pedal. This affects cruise control, brake assist, and traction control operation, as well as the brake lights, so it seemed that if this was faulty, it would explain all my problems.