Mercedes E Klasse Cruise Control Problem Solved

That's frustrating. Something similar happened with my old Volvo. The cruise control quit, and I got a generic error. It turned out to be a corroded connector in the engine compartment. The Volvo was sensitive to voltage drops, and the connector's condition stopped the cruise control. Have you checked connectors and wiring for corrosion or damage?

Thanks for the tip! Which connectors should I focus on? Are there any related to the cruise control system or throttle body known to be problematic on these cars?

On my Volvo, a connector near the throttle body was the culprit, though I'm not sure if the Mercedes is similar. Given the error code and your throttle body suspicion, that's a good start. Also check near the cruise control module, if you can locate it. If you're not comfortable probing with a multimeter, a workshop can diagnose it efficiently.

Thanks again! I took it to a local workshop. They confirmed a bad connector, as the error code suggested. Repair cost 95€. Everything works now!