Knowledge base · Makes & OEM
Mercedes W205 and W213 — the faults we see most often
The C-Class W205 and E-Class W213 are solid cars that cover a lot of miles. Precisely because of that, at higher mileages we keep seeing the same points return — and some of them cause complaints that look like something else entirely.
The auxiliary battery: far more faults than you would expect
Both models have, alongside the main battery, a smaller auxiliary battery that keeps the electrical system stable, among other things during start-stop. When it weakens, voltage briefly sags during starting — and the dozens of control units in the car notice immediately. The result is a dashboard full of messages that appear unrelated: a driver assistance warning, a comfort system fault, start-stop no longer working.
Replacing part after part at that point gets expensive. So we read out first and look at the voltage picture and the history. The same principle as with faults caused by a poor earth connection: one electrical cause, many symptoms.
Oil leaks at higher mileages
On the diesel engines we fairly regularly see leaks around the oil cooler seals and the oil lines to the turbo. Recognisable by oil on the engine undertray, a burning smell after driving and oil consumption without blue smoke from the exhaust. Repairing early is cheaper here: oil reaching hot components attacks the rubber and wiring around it.
Suspension: bushes and control arms
The front axle on both models is tuned for comfort, with relatively many rubber bushes. At higher mileages that produces rattling over bumps, vague steering and sometimes uneven tyre wear. On the W213 with air suspension there is the air system too: air springs slowly developing leaks, recognisable by a car sitting low or lopsided in the morning and only rising after starting.
Electrically operated systems
The electric parking brake, electrically adjustable seats and tailgate operation are comfortable until they play up. Note that when working on the rear brakes it is mandatory to put the parking brake into service mode via the diagnostic equipment and reset it afterwards — see adaptations and service resets. Without that step you risk damaging the actuator.
Diesels: AdBlue and emissions systems
On the diesel engines, messages around AdBlue and the SCR system occur regularly, often with a counting-down warning that ends in a no-start condition. That deserves its own article: see understanding AdBlue and SCR messages.
What we do
We have the original factory diagnostic equipment for Mercedes-Benz. That means we read out all control units — not just the engine — and can carry out the coding, adaptations and service resets that belong with the repair. With a car showing several messages at once, we start with the voltage and the history; that prevents parts being replaced that were never faulty.
Want the cause found instead of guessed? That is brand-specific diagnostics in Tilburg.
Independent garage — not an official dealer. Brand names and model designations are used solely to indicate which vehicles we carry out this work on.