james_neumann1

SM3 additional battery alarm defective

Hey, my 2009 Renault SM3 (electric engine) is throwing a weird alarm. The display says something about the additional battery alarm system being defective. I checked and yeah, the alarm doesn't work. The error's stored in the memory. Could a dead battery be the issue even though the car starts fine?

4 comment(s)

Possible. The main battery might be okay, but the alarm system often runs off a smaller, separate battery. If that one's old or discharged, it could cause the issues you're seeing. How old is that battery? Have you had it checked?

I'm not sure how old it is. I haven't checked it either. Where exactly is the battery for the alarm system located in the SM3? Is it easy to get to?

Honestly, finding it and testing it yourself might be tricky if you're not familiar with car electrics. Given the symptoms and the error code, it's quite likely the auxiliary battery. A workshop can quickly confirm and replace it. Better than causing further issues.

Okay, I understand. I'll take it to a shop. They said it was the auxiliary battery, just like you thought. Cost me 330€. Thanks for the help!

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