2014 Smart ED Cabrio keeps shutting down

[Berengar_Witcher]

Hi everyone, I absolutely love my 2014 Smart ED Cabrio, which I bought used for $7,000 about six years ago. It's been a fun and reliable little car, but it’s recently developed a pretty frustrating issue that’s becoming more frequent, and I’m not sure what to do next.

Here’s what’s happening:

About six months ago, the car started randomly shutting down. When it does, it’s completely dead, you can’t even shift it into neutral to push or tow it. The strange part is that the 12V battery seems fine (lights, radio, gauges all work), and the state of charge gauge shows the HV battery still has charge. It usually takes multiple attempts to restart, jiggling the key, waiting, etc., and eventually, it starts working again.

I replaced the 12V battery (for the second time since I bought it), hoping it would fix the problem, but no luck. It’s happening more often now, and everyone’s nervous about driving it in case it completely dies.

I’m in Los Angeles and wondering if there’s a repair shop that might be able to help. I could tow it to the one Mercedes dealer here that still works on these cars, but I’m bracing for them to suggest replacing the HV battery, which I’ve seen can cost a fortune.

if you know of a good shop in LA that could diagnose or fix the problem without jumping straight to "replace the battery," please let me know!

 

[Evholic_34]

Start by reading the error codes to figure out what is going on. It could be an insulation fault, isolation issue, or chafed wiring causing the shutdowns. Any good independent mechanic can scan the codes, but one with EV experience is your best bet. The Mercedes dealer can check it too, but I am pretty sure they will say you need to replace the HV battery (and yes, that won't be cheap). Also, if you have an OBDII reader, scan the codes and see what you get.

 

[Qunari_Qun]

That’s a frustrating issue, but it’s not unheard of with the 2014 Smart ED. From what you described, it might not even be the HV battery at all, often, it’s a communication fault between the 12V system and the HV system. I’d start by checking all the ground connections and ensuring the 12V battery cables are secure and free of corrosion.

There’s a shop in LA called “GreenTech EV” that specializes in electric vehicles, including older Smart cars. They’re known for not jumping straight to “replace the battery” and taking time to diagnose the root cause. I’d give them a call before heading to the dealer, they might save you a small fortune!