Where is the reset button on my Mercedes?
Access the onboard diagnostic menu via the instrument cluster. Scroll to “Reset” or “Check Engine Light” options and confirm. If you are just disconnecting the battery, taking all wires off the negative terminal is sufficient. I’ve tried so many different resets. This is what works for me everytime. Remove positive battery cable for 24 hours.Identify the negative battery terminal, which is usually marked by a black cap and a negative (–) symbol. The red positive (+) terminal will be close by. Use a wrench to loosen the negative terminal bolt, and then take the negative cable and hold it aside. Keep it off of the battery for 30-60 seconds.Disconnecting the negative battery cable for 30-60 seconds should clear the check engine codes and reset the diagnostic system. If you set the negative battery cable to the side, make sure the cable does not touch the battery or any metal parts of the vehicle to avoid grounding the circuit.