Greetings! My beloved 2012 Megane 3 RS delivered me to my home today (good girl) and then promptly shut down on its own, and would not restart (it would not engage starter at all). Dash was displaying "Check ESC" and "Check Injection", followed by "Check Start/Stop". Oh dear. Pulled the key and re-inserted, and it completed the self-check, dash displayed "OK" and the motor would start. It ran for about 30 seconds and died again with same messages. Tried to read codes while dash was displaying errors and car was 'on'. The OBD port has power and scan tool lights up, but it cannot communicate with the car. Pulled key, re-inserted, and it checks OK again, and then tried the OBD scanner which CAN NOW communicate with the car. It had no fault codes stored. Without starting the car this time, the faults returned, and OBD scan tool looses communication again. Pulled key, re-inserted, health check is OK and car starts up and runs flawlessly. I'm thinking this is the ECU flaking out. But I'm looking for other common causes or common denominators before I start throwing computers at it. Additional info: Battery is 12 mo. old and tested fine, terminals are fine. No obvious sign of corrosion around battery or connectors. Unplugged battery for a few hours to 'reset'...lol nope. Car is producing 13v while running. There is an odd sound coming from the around the MAF / injectors when not running (high-pitched screeeeee, may be normal?) Megane has 60k KM, never wrecked, garage kept. All stock. Thanks in advance. --Brad
Assuming anyone is curious: The problem turned out to be a failing throttle body unit. This was also the source of the odd noises as the stepper motors within it were seizing up. Why this freak out prevented the OBD from being communicated with, I have no idea. Never encountered that before. --Brad
