Mercedes-Benz S400 power electronics control system failure causing starting issues on Mercedes-Benz S400

Some Mercedes-Benz S400 owners report experiencing starting issues attributed to power electronics control system failures, which can manifest as the vehicle not starting at all or starting intermittently, where dash lights and ignition activate but the engine fails to engage. Common reasons for these starting problems include dead batteries, alternator issues, or a failed starter. Additionally, hybrid battery failure is a typical concern for S400 hybrid models, as a significant drop in charge levels below 15% can disable the engine start function. Many owners also find that weak or dead batteries can prevent the starter motor from functioning correctly, leading to clicking sounds or no response when attempting to start the vehicle. It is crucial for owners experiencing these symptoms to follow a proper diagnosis and repair guide to effectively resolve the issue.