I have been considering buying a 3rd gen 2019 to 2023 CLS 450 and found articles on wiring harness problems for the M 256 engine that is used for the CLS and other MB models. It was reported that the wiring harness was found to be deteriorated from exposure to heat from the engine. This was typically discovered while performing spark plug replacement at the 60K service maintenance and required expensive replacement. Have any 3rd gen CLS owners experienced this?

 

All of the M256 engine have this issue. Wiring and the transmission wire needs to be inspected before purchasing the vehicle. There is a recall for corroded wiring harness connector on transmission. Please do your research before purchasing this vehicle with the M256 motor

 

Thanks GT53. I really like the CLS Class and regret that it was discontinued. I have decided to look for other years and classes that have shown less problems. I'm glad I didn't pull the trigger on the 1st 2 years of the last generation CLS with the M256 motor.