W210 - where exactly is the ECU?

[Chris Frost]

Hello chaps,

Noob here so I've been soaking up some knowledge from past threads for the last couple of days before posting my first question

My E320 CDI (WDB2100262B421182) is on a 51 plate and it's developed the BAS/ABS/Limp Home Mode problem. On top of that the battery isn't holding charge; but I think that is a separate issue. The car wouldn't start even jumped from another. (New Bosch 019 100Ah 460/800 due tomorrow)

Reading up here it looks like there are two possible causes -
1) the brake light switch
2) a lose connection causing problems with the ECU.

I don't know if my diagnosis is right (comments please), but before the car died I had a short period where Limp Home Mode was intermittent. Sometimes travelling down hill the car would cure itself and be OK for a while. Going up hill the problem would return, so I'm thinking the ECU fan is worth a look before I replace the brake light switch.

I've checked the Merc hand book. Not much info there. Can anybody point me in the direction of a good paper workshop manual or tell me where the ECU is located?

Thanks in anticipation.

 

[television]

Hello and welcome, if the battery is low it will put on the ABS BAS lamps due to the blip when starting, without having the full 12 volts all other things are meaningless.

If the battery is the original then why not replace it first.

there is a mod on your car where the fan goes short circuit stopping the car from starting as it is wired over the engine ECU

Email me and I will send you the mod

 

[Chris Frost]

Hi Malcolm,
Thanks for the fast response

New battery goes in tomorrow, so fingers crossed that that sorts out some of the issues.

Email on its way re the mod.

Thanks

edit: Your profile doesn't allow me to send an email to you. My email address is chris***@lucidavinks.plus.com (anti spam - remove the *** three stars for correct address)

edit2: scrap that. I've just found the vcard thingy. Oohh, aren't you lot posh here

 

[television]

I will do it Wed, we have to be posh with our MB's

 

[hmang]

as malcolm.
bung a battery in. you may as well do the brake light switch too...if it's not the cause of a problem yet, it soon will be.

 

[television]

If you do change the Brake light switch its only £9 and one 17mm nut easy to do

 

[BlackC55]

There is no 17mm nut in the 210 brake light switch. Its just a twist action to remove

 

[television]

There is no 17mm nut in the 210 brake light switch. Its just a twist action to remove

So that was not a nutty post from me then

 

[BlackC55]

that was terrible Malc.

Regarding the 210 the basics MUST be checked first before any hint of an ECU problem is looked at.

 

[television]

that was terrible Malc.

Regarding the 210 the basics MUST be checked first before any hint of an ECU problem is looked at.

I am just sending him the Aux fan removal mod, where it shorted out the engine ECU

 

[Chris Frost]

She's alive, ALIVE!!!

Well, thanks to all here who's posts I read whilst searching, and especially Malcolm, my lovely E320 lives and breathes once more.

A new Bosch battery went in (£115 from Andrew Page motor factors in Manchester) and after following Malcolms instructions about disconnecting the blower fan and replacing a 10A fuse she fired up first time.

BTW, the one question no-one answered was "Where's the ECU?" For those with a similar question the answer on my E320 is it's at the righthand rear quarter of the engine bay. It's the big box marked Air Conditioning.

I'll take the advice of others here re the brake light switch. I'm sure I'm not out of the woods yet, but I can see some sunlight on the path.

Thank you one and all.

Regards

 

[television]

Hi Chris, I have sent you the mod for the fan, you could think about doing it or at least adding an in line fuse from the fan module

 

[BlackC55]

Well, thanks to all here who's posts I read whilst searching, and especially Malcolm, my lovely E320 lives and breathes once more.

A new Bosch battery went in (£115 from Andrew Page motor factors in Manchester) and after following Malcolms instructions about disconnecting the blower fan and replacing a 10A fuse she fired up first time.

BTW, the one question no-one answered was "Where's the ECU?" For those with a similar question the answer on my E320 is it's at the righthand rear quarter of the engine bay. It's the big box marked Air Conditioning.

I'll take the advice of others here re the brake light switch. I'm sure I'm not out of the woods yet, but I can see some sunlight on the path.

Thank you one and all.

Regards

It is in the big box with the air con sticker on top. There are a few in there. Esp, engine etc.

The term ECU is normally refered to Electronic Control Unit. Not Engine control unit. An ECU can be a number of things such as gearbox, esp, engine keyless go etc etc

 

[television]

It is in the big box with the air con sticker on top. There are a few in there. Esp, engine etc.

The term ECU is normally refered to Electronic Control Unit. Not Engine control unit. An ECU can be a number of things such as gearbox, esp, engine keyless go etc etc

Thank goodness there is no more eric, he would not have accepted that answer

 

[BlackC55]

Do you think he would have disagreed?

 

[television]

Do you think he would have disagreed?

Yes he told me the only ECU on my car was the engine ECU, that lasted 2 postings, mind you he never told me what the rest were.

 

[Chris Frost]

It is in the big box with the air con sticker on top. There are a few in there. Esp, engine etc.

Yeah, I....already......found........it. That's why I wrote in a previous post...
"it's at the righthand rear quarter of the engine bay. It's the big box marked Air Conditioning".,

It's a pity you didn't chip in when I first posted the question a couple of days ago, but thanks anyway

 

[Chris Frost]

Piccies to help other noobies in the same boat

Regards

 

[television]

Bobcat please DIY this its very good I can add some words re the mod

 

[Blobcat]

Write it up as a DIY and I will copy and move it across