Desperation

[Mercedes20001]

Hi

Well I was unable to get the code read - the guy said that he simply couldn't get the reader to talk to the ECU.

So, it could basically be anything, knackered ECU, some random induction/vacuum pipe - who knows!

But I'm screwed without a car - all suggests & advice welcome.

Thanks in advance.
Adam

 

[television]

Hi Adam, what is the car, year type and model, and what is wrong with it

 

[Blobcat]

A W124 E280 here

 

[kth286]

cappsie

strange !

Was it a Merc specialist ?

Were there other Mercs there of a similar age to your car ????

It needs to be someone that is familiar with the older Merc, as the latest diagnostic tools used for the latest OBDII are NOT suitable.

A simple flash code reader is all that is required, along with a list of written descriptions of each code, to be able to descipher.

 

[Mercedes20001]

Hi

Right an update that might shed some light - I was browing ebay looking for a coil pack when I came across this: http://cgi.ebay.co.uk/Mercedes-VDO-...ryZ10398QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Now the thing is mine doesn't idle and when it's running it's missing, plus when this guy put the reader on there he couldn't read the ECU - it all seems to point to a knackered ECU - but how can I prove it?

On that ebay ad they say that if you replace your ECU you should also replace the coil packs as they can re-blow the ECU.

Has anyone ever experienced anything like this?

Adam.

 

[Mercedes20001]

I don't suppose anyone knows the part number for this ECU and model etc?

adam.

 

[kth286]

cappsie

You have hidden from us the fact the car was missing, until now. !!!!!!!!

Are you at all mechanically minded, as it is very simple to change a coil pack that sits on top of the spark plugs under the top engine cover.

There are three coils, each feeding 2 cylinders.

So, when a coil goes down, the car then only fires on 4 cylinders.

You need to buy ONLY Merc coils from the dealer and give your VIN to the parts man. (about £50/55)

You can then substitute each coil in turn, and if the missing improves, you have found the dud coil.

Is the car new to you ????????? Do you know any history at all ???? let us know if you do and we might be able to help some more.

These cars do suffer from engine wiring loom problems and that could be you problem, but also coils do go any number of times, and you need to check that out first.

If the same coils kept blowing then I would say you need to look at the loom, but at this stage do not complicate matters and just concentrate on that coil.

Do you feel your mechanic was familiar with your type of car. I ask because you have not responded to my previous questions. Help us to help you, by answering any questions asked of you.

 

[Mercedes20001]

Can I get the coil packs anywhere else or only from a merc dealer?

It is missing and this could be one of the reasons but it's the lack of idling that concerns me plus the guy not being able to read the ECU ...

What are the chances that the coil pack could have blown the ECU?
Would the engine still run ok with a buggered ECU?

 

[kth286]

When the coil feeds in the wiring loom short, if it is bad enough it can cause the output drivers in the ECU to blow.

So, if one of the output drivers (there are three) have blown in the ECU the engine will still start but only fire on 4 cylinders.

So, what is the history leading up to this ???????

I would get a coil from the dealer, as you are going to need one anyway even if the ECU has blown and you get a new/repaired ECU.

As far as electrical products are concerned ALWAYS get the dealer item.

Experienced practitioners will confirm this time and time again.
There are lots of dubious electrical products out there that do not meet the manufacturers spec and indeed can cause ECU problems.

Just because the mechanic's tool could not speak to the ECU does not mean the ECU has blown.

 

[kth286]

cappsie

Just a thought, if you are far from a dealer then Inchcape do next day delivery.

See www.mercedes-benz-parts.co.uk

You will see the phone number 0845 125 8999 and you can give the guy your car VIN number from the windscreen, and that will ensure you get the correct coil delivered next day.

 

[Mercedes20001]

When the coil feeds in the wiring loom short, if it is bad enough it can cause the output drivers in the ECU to blow.

So, if one of the output drivers (there are three) have blown in the ECU the engine will still start but only fire on 4 cylinders.

So, what is the history leading up to this ???????

All I know is that since I got it it's never idled properly, my mate cleaned out the air system effectively and it won't idle whatsoever.

We've tried several times to read the code but to no avail.

I would get a coil from the dealer, as you are going to need one anyway even if the ECU has blown and you get a new/repaired ECU.

So simply get a new coil pack and test all cylinders see if that helps - however if the ECU is blown surely this won't actually do anything?

As far as electrical products are concerned ALWAYS get the dealer item.

Should I not try a refurbished ECU or perhaps send mine off for testings or perhaps repair?

Just because the mechanic's tool could not speak to the ECU does not mean the ECU has blown.

Hmm fair point, but there doesn't seem to be a way to tell if the ECU is definately working or not

 

[Mercedes20001]

cappsie

Just a thought, if you are far from a dealer then Inchcape do next day delivery.

See www.mercedes-benz-parts.co.uk

You will see the phone number 0845 125 8999 and you can give the guy your car VIN number from the windscreen, and that will ensure you get the correct coil delivered next day.

Can they get any part number just from the VIN?

That would *really* help me out

I've spoken to a few people spares-wise and have been quoted £39.99 upwards to £200 and £400 for a refurbished ECU - way too much money - seeing as I only paid £130 for it

 

[Mercedes20001]

Hi

Ok I *think* this is my VIN - at least it is according to the MoT Certificate:
WBD1240282C115929

 

[kth286]

What did you only pay £130 for ??????????????? The car ?????????????

What were you told about the condition of the car when you bought it ?????

Give the VIN to the parts person on that phone number and get a coil - the worst that can happen is that you end up with a spare coil - no bad thing.

 

[BlackC55]

Ignore the Engine control Unit fault for the time being. Just because it couldn't be read by your mechanic does not mean its kaput.

Concerntrate on the missfire and which cylinder it is affecting then go from there.

Basics first.

 

[Mercedes20001]

What did you only pay £130 for ??????????????? The car ?????????????

What were you told about the condition of the car when you bought it ?????

Give the VIN to the parts person on that phone number and get a coil - the worst that can happen is that you end up with a spare coil - no bad thing.

I knew there was some idling problem when I get it but the dealers said it was something to do with transmission which it clearly is NOT.

In short it was a mate and they said they only wanted what it would cost to scrap the car - they just didn't need it and clearly didn't need the money.

 

[Mercedes20001]

Ignore the Engine control Unit fault for the time being. Just because it couldn't be read by your mechanic does not mean its kaput.

Concerntrate on the missfire and which cylinder it is affecting then go from there.

Basics first.

Sounds like a plan - how much am I looking at for a coil pack ?

 

[Ian B Walker]

And dont forget to change the rubber plugs from the coil pack to the spark plug. I spent ages trying to cure a missfire on a C class, ended up at a £5 piece of rubber

 

[Mercedes20001]

I got quoted £70 + Vat for ONE coil pack

Not exactly the 'cheap' part I was informed it would be - seeing as I still don't know whats wrong is there no other way of testing the engine?

Surely if it's missing/misfiring I can do the unplugging of the various coil packs...?

 

[kth286]

Try that and see what you find out. It is one way. But that is only going to tell you which cylinders are down.
It will not fix the car.

If you intend to keep the car then having a spare coil is a benefit. Or you can sell it on if you keep proof it is an original part and the keep the receipt.

Many cars use that coil.