DesertDog18

Hey guys, need some help. My car occasionally didn’t want to start the last few weeks. It had gotten cold in Arizona so I thought the battery was going dead. But I went to jump start it and it still won’t start. I put it on an MB trickle charger for a few days, I get green light fully charged, it did start one day after this. But two days later, even with green light on trickle charger, it won’t start, just clicks when I press button. I tried trickle charging from the trunk and at the specified jump points. I put a tester on my battery & it’s showing 13.4 volts.

here’s the weird part, it will start when I put the key in the console & start it. But it won’t light up the transmission lights, so I can’t shift it in order to drive it. Plus, there’s multiple warning lights on the dash when I start it from the console. I have changed the key batteries.

any ideas?

DesertDog18

Hey guys, wanted to give an update. I called MB roadside and they came out (even though car is out of warranty, I paid $125), he tried to charge it, even hooked it up to the computer but couldn't get it to start. This is a good option if your car is doing something weird, had he been able to fix it, I would have only spent $125. That beats a tow truck & dealer charge any day.

The next day I go out & the car miraculously starts?? I drove it to the dealer. They looked at it, said they had to clear a ton of codes, charged the battery & said it was holding a charge. They still recommended a new battery anyway for $3200. I picked the car up & took it to my regular Benz mechanic to see what he said. He looked at and said the battery is testing fine, no need to replace. I've been driving it ever since, no issues. I do know for sure but I think Mercedes has special equipment to charge/reset these lithium ion batteries that may be different from the MB trickle charger I have at home. If this issues crops up a year or two from now I'll probably take it back to the dealer & have them charge it again & see what happens. If it comes back a month from now I'll replace the battery, my local independent Benz mechanic quoted me $2400.

My take on the whole thing... When it wouldn't start the first time I tried charging it every which way over a few days: at the battery post, at the specified charging posts in engine bay and at the plug in the trunk. I'm not sure if all of this confused the computer, because it generated a bunch of codes? Because the weird thing is even when the car wouldn't start at the button it would always start from the console? But you couldn't drive it, it had warning lights on dash and no transmission lights.

DesertDog18

Hey guys, final update on this. I had my independent shop put a new MB lithium ion battery in the car and the tech discovered one of the sam units wasn’t working right. The battery, sam repair and an annual service came in at 4k. I thought that was fair. Considering the dealer quoted 3500 just for the battery. Hope this helps anyone else who encounters this issue.