Battery malfunction
Thread Starter
Junior Member
Joined: Feb 2018
Posts: 18
Likes: 0
W221 S500
Battery malfunction
Hi guys. Owning a 2021 S500. 2 weeks ago, got an error : SRS Restraint system yellowish and red sign for airbag. 3-4 days after this got red notice "Malfunction" and battery icon.
The dealer could check this up at least in 3 weeks. Meanwhile hooked launch and checked the errors. Starter battery is malfunction (please advice where to find it exactly).
I tested the 2 batteries in the trunk - they're in good shape, also checked the other battery through the charging terminals in the bonnet - its good too.
Any advices to fix prior to the MB Dealer inspection? Where is the starter battery located? Could the problems be connected as in the older MB Cars - SRS was shown when the voltage drops.
Thank you in advance.
Regards!
The dealer could check this up at least in 3 weeks. Meanwhile hooked launch and checked the errors. Starter battery is malfunction (please advice where to find it exactly).
I tested the 2 batteries in the trunk - they're in good shape, also checked the other battery through the charging terminals in the bonnet - its good too.
Any advices to fix prior to the MB Dealer inspection? Where is the starter battery located? Could the problems be connected as in the older MB Cars - SRS was shown when the voltage drops.
Thank you in advance.
Regards!
Member
Joined: Mar 2020
Posts: 148
Likes: 75
From: Philadelphia area
2022 - S580 and 2019 Porsche Carrera S Cabriolet
Sorry, I don’t have an answer to your direct question, but, DO remember to lock the car every time you leave it parked. If you leave the car unlocked the battery is still draining very slightly. Not a problem for a few days, but after long periods of time unlocked will drain the battery.
Junior Member
Joined: Jun 2009
Posts: 29
Likes: 2
From: Irvine, CA
2022 S500
I just had the following yellow errors on my 22 S500 after multiple 12V low ‘please start engine and drive 30 minutes’. Drove the car for hours over several days with auto start/stop in off mode just to make sure the battery charges.
-lane keeping assist inoperable
-check engine light on
-Distronic plus inoperable
-traction control inoperable.
I just used a CTEK 7002 battery charger from my old Bentley Flying Spur ‘which had a chronic battery drain’ in hopes that this won’t happen again. Codes have cleared for now.
I think it’s either a voltage converter issue or these cars need a trickle charge. I’m also trying the double lock option on the key fob to deactivate the keyless go range sensor from draining the battery. I’ll keep you posted on the results!
-lane keeping assist inoperable
-check engine light on
-Distronic plus inoperable
-traction control inoperable.
I just used a CTEK 7002 battery charger from my old Bentley Flying Spur ‘which had a chronic battery drain’ in hopes that this won’t happen again. Codes have cleared for now.
I think it’s either a voltage converter issue or these cars need a trickle charge. I’m also trying the double lock option on the key fob to deactivate the keyless go range sensor from draining the battery. I’ll keep you posted on the results!
MBWorld God!
Joined: Dec 2019
Posts: 33,219
Likes: 6,597
I just had the following yellow errors on my 22 S500 after multiple 12V low ‘please start engine and drive 30 minutes’. Drove the car for hours over several days with auto start/stop in off mode just to make sure the battery charges.
-lane keeping assist inoperable
-check engine light on
-Distronic plus inoperable
-traction control inoperable.
I just used a CTEK 7002 battery charger from my old Bentley Flying Spur ‘which had a chronic battery drain’ in hopes that this won’t happen again. Codes have cleared for now.
I think it’s either a voltage converter issue or these cars need a trickle charge. I’m also trying the double lock option on the key fob to deactivate the keyless go range sensor from draining the battery. I’ll keep you posted on the results!
-lane keeping assist inoperable
-check engine light on
-Distronic plus inoperable
-traction control inoperable.
I just used a CTEK 7002 battery charger from my old Bentley Flying Spur ‘which had a chronic battery drain’ in hopes that this won’t happen again. Codes have cleared for now.
I think it’s either a voltage converter issue or these cars need a trickle charge. I’m also trying the double lock option on the key fob to deactivate the keyless go range sensor from draining the battery. I’ll keep you posted on the results!
To OP, Hopefully that also solves it for you.
Junior Member
Joined: Jun 2009
Posts: 29
Likes: 2
From: Irvine, CA
2022 S500
So, it seems the 12V is still draining despite attempts to drive for hours and also to double lock the key fob to stop the continuous transmission of signal with the car. Seems to me that the voltage converter is defective as suggested above. Not sure if the recall is officially launched in the US. The car is now on a CTEK charger every three days.
MBWorld God!
Joined: Dec 2019
Posts: 33,219
Likes: 6,597
So, it seems the 12V is still draining despite attempts to drive for hours and also to double lock the key fob to stop the continuous transmission of signal with the car. Seems to me that the voltage converter is defective as suggested above. Not sure if the recall is officially launched in the US. The car is now on a CTEK charger every three days.
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MBWorld Fanatic!
Joined: Jun 2019
Posts: 2,268
Likes: 1,017
From: Costco
2025 AMG GT63, 2023 S500, 2022 GLE53
There’s a safety recall that’s affecting the 12-volt battery. More specifically the voltage converter, which sounds like your issue. I bet your battery is toast, too, partly stemming from this issue, so in addition to the recall, I would get a new battery.
https://mbworld.org/forums/s-class-w...ss-recall.html
https://mbworld.org/forums/s-class-w...ss-recall.html
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