kilroy440

Hello Folks!

I know this topic has been covered in the past, but I'm still searching for suggestions / solutions. Here's the situation:

2003 SL55 AMG, 90K miles

ABC Warning - Drive Carefully warning comes on in RED very frequently, sometimes on big bumps, sometimes on little ones. Car also was dropping low in the front-left after sitting for a few days. So far, I have:

- Replaced front-left strut
- Replaced front valve block
- Replaced ABC tandem pump
- Flushed system, rodeo test

Warning light still pops on in Red every minor bump on the highway. Dropping issue is better than it was, but still happening. However, since replacing the ABC pump, the warning light now comes on much MORE frequently than before. The warning disappears after a few seconds, and the car is NOT going into 'tuna boat' mode. Driving feels normal. My mechanic is now suspecting the computer?

Thanks for your help guys,
J.

BlownV8

Sounds like you have a bad accumulator.

kbob999

I think Blown V8 is right. With that many miles I had the 'pump' accumulator fail on my car. It is located at the rear of the left front wheel well. Easy DIY, or indy job. About $150 for the part and an hour labor. Start there.

Next, replace the accumulators at the valve blocks. Front is medium difficulty and can be done from under the car; rear is a beotch and requires removing the valve block. You may have got a new accumulator if it came with the front valve block, but not likely. Same price for parts on both of these, labor about an hour for front, maybe 3 for the rear.

The 4th one is to soften the pulse back to the reservoir under the hood, and works under much lower pressure, so rarely fails. Do this one last.

It could also be the pressure sensor located at the 'pump' accumulator going bad and giving false readings, but most would agree your accumulators need replaced at this age/mileage as a maintenance item.

Let us know what fixes it.

kilroy440

Thanks guys, my mechanic is diving into the accumulators. I will let you know how it goes...

cadbob

Mine was doing same thing, Tech thought it was Pump, I said nope accumulator is bad replaced all, but one was bad, Make very sure you Flush and Rodeo, after

kilroy440

Thanks all for your help. I picked up my SL55 yesterday, and so far I have not seen any errors or warnings!

My mechanic replaced the following parts:

(1) Part-Nr: 220 327 01 15 - "Air reservoir" LEFT
(1) Part-Nr: 220 327 02 15 - "Pressure accumulator " FRONT LEFT

My mechanic was great and replaced these for me at cost. Still waiting to hear if a rodeo and flush was done after the repair. We did not replace all accumulators or the Air Cell. I have seen other posts where these parts were all replaced:

(2) Part-Nr: 220 327 01 15 - "Air reservoir"
(1) Part-Nr: 220 327 04 15 - "Air cell
(1) Part-Nr: 220 327 02 15 - "Pressure accumulator "

So far all seems good. Would be happy to hear your guys thoughts on the situation and how likely it is that future problems will develop.

For any SF Bay Area residents I recommend Jimmy at Junipero Serra Mercedes & Porsche.

Thanks again.

kbob999

Excellent! The prognosis was correct. The rodeo is to make sure any contaminants get flushed from the system after breaking it open. The car will cycle the fluid in a few days/weeks through operation, but Rodeo gets it out on day one.

You can continue driving with everything just fine as is, but good preventive maintenance (as if this were an aircraft) would suggest replacing all of the age related parts at once. If not, it could jump up and bite you at any time. Your call, but that is what I did for peace of mind.

cadbob

I'm with Kbob, if the Diaphragm is gone in one it won't be long till another goes. I replaced all mine in one sitting. Glad your good to go!

Most definitely do a good Flush, I bought big jugs of the fluid on ebay. Towards the end of Rodeo/Flush the black crap came gushing out. We did the rodeo/flush and than once complete ran the car through the rodeo test to check for leaks, pressure and such.

mbwolf

I just want to add that I found all 4 bad in my car. I strongly recommend to replace
Part-Nr: 220 327 04 15 - as well to avoid re-contamination.