Mercedes-Benz S420 intermittent starting issue with dashboard lights, possibly related to starting switch or relays on Mercedes-Benz S420

Some Mercedes-Benz S420 owners report experiencing intermittent starting issues, even when dashboard lights function normally. These problems may stem from a failing battery, a faulty ignition switch, loose wiring connections, or fuel system issues. Additionally, electrical problems with the gear selector can complicate diagnostics, making tools like Xentry essential for identifying the root cause. Some owners find that checking the dashboard lights or ignition panel for activity when removing the key can help indicate ignition switch problems. It is advisable to seek assistance from a qualified technician or a Mercedes-Benz dealership, as reprogramming the EIS module may be necessary to resolve no-start conditions or intermittent starting problems.