"buzzing" heard after new battery install on a C30 Topic is solved

anacortesian · Post by **anacortesian** » 05 Jun 2020, 12:32

New member here,
I bought a 2009 C30 (2.5L Geartronic) 6 months ago from a private party with low mileage. The car just had it's 60,000 inspection at the dealer a month earlier and the only issue advised was low cranking amps on an older battery. The car started and ran fine so I put off replacing the battery for a later date. Then about two weeks ago the battery finally dies. Understandable. Luckily it died while the car is parked in my garage. So there was no towing or jump starting...I simply went out and bought a decent new battery and replaced it myself in the garage. Remembering to remove the negative terminal first as well.
So with the positive cable connected first and then carefully connecting the negative cable (there was some sparking at the negative terminal which I've read is expected) But what did strike me as weird...there was this rather loud and distinct "buzzing" sound seemingly at about the middle of the engine bay...as if some relay buried there were going crazy for a few seconds...then it stopped...so I could not determine the exact location.. The car starts and runs fine.
[There is a "next day" issue that I'm dealing with which involves the dreaded urgent warning seat bag light on"SRS-CFFF code - control module internal fault". But this appears to me to be an unrelated issue, as there was no crash or airbag deployment, no radio removal or any electrical work done, no liquids spilled on the center console, and the instrument cluster is working properly. So I'm going to pull the module and send it the UK for a reset].
But has anyone has had this "buzzing relay sound" issue after replacing a battery?

Post by **kranz** » 07 Jun 2020, 10:41

I have a 2006 V50 and it on occasion does this buzzing act. When it first occurred I thought it was some sort of problem. But now I suspect it is related to the network of electronics under the hood. It is my impression that the electronics does not shut off immediately when you turn off the ignition key. It may take a few minutes for it to gracefully shut down all its functions and goes to sleep. The buzzing in my car goes away after a short while. It is also recommended that you wait a period of time after turning off the key before you disconnect the battery. That allows this process to take place.

Also there is a proper procedure to reconnect the battery. IIRC the key must be in position 2 before you reconnect. Failure to follow this procedure can but not always have unpredictable results with the electronics possibly misbehaving.

Of course I may be wrong on some or all of this, but it is my impression of how it works.

anacortesian · Post by **anacortesian** » 07 Jun 2020, 12:15

KRANZ

Thank you for your informative reply. I'm new to this car...but perfectly capable of Auto-electro-understanding (I was a photocopier technician in my previous life). Anyway...I think you may be accurate. There are three other members here that have suspected the same thing as well (some kind of relay aligning itself after an initial voltage spike IE: the battery re-connection). Okay. Fine. Then hopefully no new issue is audibly crying out click-click-click to me for attention. The way I understand this car now is... 1) never do ANY electrical with the battery neg lead connected (and I did not). 2) Wait at least 10 minutes (min) before proceeding to any next procedure.(I think I did) . And 3) Always disconnect the battery NEG lead first and reverse the order for re-connect...and keep the key OUT of the ignition through the whole bad dream!.

Post by **MoVolvos** » 08 Jun 2020, 17:59

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Take a look it may be the brake booster. Our 2008 had the same buzzing from the booster but it resolved itself. Careful super hot.

Almost replaced it.
https://www.pelicanparts.com/techarticl ... cement.htm
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anacortesian · Post by **anacortesian** » 08 Jun 2020, 18:11

Yeah...a couple of other members here have said "don't worry about it...it's just a volvo relay alignment thing". So you may be right. And by the way, I think "Pelican Parts" is a pretty interesting company. I've bookmarked them for important information that they consistently have available. And a lot of parts for our cars.

Thanks,
Gary

Post by **MoVolvos** » 08 Jun 2020, 18:38

anacortesian wrote: ↑08 Jun 2020, 18:11 Yeah...a couple of other members here have said "don't worry about it...it's just a volvo relay alignment thing". So you may be right. And by the way, I think "Pelican Parts" is a pretty interesting company. I've bookmarked them for important information that they consistently have available. And a lot of parts for our cars.

Thanks,
Gary

Hi Gary,

Pelican use to be more Porsche and was only a handful of online sellers which carried Swepco Products. I think the factory uses their trans fluid in the GT3's and others with 100K change intervals. I use to purchase 4 of their products by the case when I was in CA and still can here in NC as the local rep is close by but the price has skyrocketed so it is now cost prohibitive to use.

https://www.pelicanparts.com/cgi-bin/ks ... o+Products+

Not sure where you are in CA but if you are in the Bay Area and need repairs done.

https://www.yelp.com/biz/montclair-auto ... -oakland-2

http://www.montclairautotech.com/customers.php
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anacortesian · Post by **anacortesian** » 09 Jun 2020, 09:37

BKM

Thanks for your reply. I'm in the N County area, Oceanside. Let me know if you remember any good Volvo garages you might have heard about down here? I'm new to CA.