the head

Well after an extended period of sitting (it's a long and grueling story that I won't get into) the aux battery in the trunk died. I had the typical battery warnings on the dash (apparently the main battery was also low at some point) and the 'convenience' message for the aux battery. Anyway after a trip to Pepboys, I replaced the rear battery and had a bunch of things not working right. I did figure out the window synch and the ESP reset thanks to this forum, but the locks and the trunk release didn't work - nor the top fold down. After reading around it had to be the PSE. The top will not move since the trunk never 'closes' without the soft close function to pull it all the way down. I checked the fuses under the hood and the one behind the passenger seat - all good. And after moving the hydraulic pump out of the way verified 12.4 volts going into the PSE black box.

For those of you that have experienced the PSE going out - is there anything else that I'm missing? I just want to cover the bases before going to the dealer. I do have the CPO extended warranty through MB, but the service department hasn't impressed me a whole lot in the past so if it was a quick fix I was just going to do it myself.

I also posted this in the AMG thread - sorry for the cross-post.

the head

Ah, the joys of the dealerships. They're telling me that both batteries need to be replaced. Even the new one I just put in. I know that is crap since bother batteries sit over 12v with a volt meter and increase when the car is running. They're claiming neither one wants to take a charge, again baloney becase I charged both batteries up before hooking them up when installing the new one. So of course they want $700+ for both batteries, I told them I would do it myself. The car starts and runs just fine. And there is no "convenience" message indicating low voltage for the aux battery. Joy.

the head

OK picked the car up and after challenging a few things the service advisor there (not the one I was dealing with - he had already left for the day) he looked through the paperwork and said that only the front battery failed the discharge/charge test which made more sense. They cleared the battery code and it didn't return. So I'm going to get a follow-up call tomorrow morning to talk about options. I still don't get where they charge $700+ for changing out two batteries. I'm finding the battery I need (genuine MB) for less than $200 online. I checked the batteries again after getting home - they released the car to me. Both are right at 13 volts. I did have the engine battery tested (I took it out) and it passed with something like 770 cranking amps with the battery rated for 520 amps. More to come - just logging info in the thread in case it helps anyone down the road.

the head

Last post. After charging both batteries with a trickle charger - unhooked from the car and then reinstalling, they pass the battery test. This basically required having them totally charged. Mine top out at 13.4v with my particular charger. So after that, they addressed the real issue and it was indeed the PSE pump, covered under the extended warranty.