Auto Transmission Control Unit

[shortshooter]

Hi.
I have a problem.
My gearbox was slipping between (I think) 3rd and 4th gear.
I took the car, E320 CDI, to my local MB dealer.
They told me it was the Electronic Gear Selection Module.
I Paid £460 + Vat + Labour = £670.
Part no (I think) A 030 545 20 32.
Afterwards the problem was still there,exactly the same, and they could not get the car in until another 4 days.
On re-inspection they told me it was an oil seal on the gearbox leaking oil onto a multiplug.
When I asked the Mechanic if the old control Unit (which I kept, just in case)could now be replaced, I was told yes but I would have to confirm with the manager.
The next day the team Manager rang to tell me that oil had contaminated the Control Unit so it couldn't be used.
Obviously I wasn't amused so I went in and saw the Service Manager.
I was now told that they would try the old Control Unit, to check if it was damaged, after the oil leak was fixed and multi-plug replaced.
I am still waiting after 9 days (back order apparently) for this.
I still have the old Unit, which is covered in oil and raises another question,
how did they not realise there was an oil leak when they swapped the part and put the new one in?
And gave me the car back!
Am I being given the runaround?
Please help.
Thanks.
Jon.
P.S. Does anyone know if this Control Unit can actually be reached by oil leeking from the gearbox.
I am under the impression that it is located under the drivers side of the dashboard!

 

[cruicky68]

It sound very fishy!! I was lead to believe the control unit was under the dashboard, so how it got covered in oil I don't know.

 

[stwat]

Its actualy quite a well known problem. The seal on where the cable exits the gearbox fails and allows oil to travel up the cable to the control unit. I've read about it on a number of other sites. Il try and post a link to one for you.
I found the link http://www.mbclub.co.uk/forums/showthread.php?t=12199&highlight=control+unit
Stu

 

[shortshooter]

Jon

Its actualy quite a well known problem. The seal on where the cable exits the gearbox fails and allows oil to travel up the cable to the control unit. I've read about it on a number of other sites. Il try and post a link to one for you.
I found the link http://www.mbclub.co.uk/forums/showthread.php?t=12199&highlight=control+unit
Stu

Firstly, thanks for the help.

I looked at the picture and I still can't see how oil can travel up an electric cable!
Please explain more.

 

[jberks]

I understand that it is forced up between the wire and the insulation, effectively forming a nice oil pipe to feed from the gearbox up to the ECU. Remember, the oil in the gearbox is under high pressure so it doesn't take a lot. You would have though that given the apparent frequency of this issue, Merc would have redesigned the plug with a connector part way up the cable so the oil couldn't go any further. Then again, they get to sell you another ECU.
Out of curiosity guys, how many wires are there? How hard would it be to put a small split in the insulation on each wire and then tape over, effectively allowing the oil to leak out rather than travel all the way to the ECU should the seal go.

 

[Locky]

I had exactly the same problem as you... it was diagnosed today. I've also found I can't get the new multipin plug. The MB specialist topped up the box for me and said they would give me a call when the plugs are in. Does anybody know where these are available. Or even a part number would be handy.

 

[shortshooter]

The Multi pin plugs have arrived. Mine's been done.
The outcome of my situation continues thus;
The MB Dealer has refunded my £660, refitted my old Control Unit, not charged me for fixing the leak and fitting a new multi-plug (because they should have spotted the leak before they replaced the CU) but charged me £200 for cleaning the oil from the CU.

Any how the gear slipping is STILL exactly the same as in the very first place.
Two Control Units later and a new Multi-plug.

The Computer read out now says it is a Mass air flow sensor.
Well this has already been renewed a week before all the rest, so it was replaced again (free of course) but they tell me it may not be fixed now.

Too early to tell as it is intermittent.
Watch this space.

Does any one know what else it may be.
One of the symptoms is a lack of power and no kickdown.
If I turn off and restart it is fine for a while.

Thanks in advance.
Jon.

 

[piestore]

lack power

HI


Gearbox is fine sounds like a lack of engine power, the electronic gearbox gets very confused if the engine is down on power/torque, ask for the fault codes for both ETC and CDI , I would put money on (only a small amount) CDI reporting a boost pressure control fault

 

[shortshooter]

Thanx Piestore.
I'll get it looked into.

For an update I can say that it seems to be changing gear a little better but the main problem now is the lack of power, no kickdown and slow.
Like I have said already, when I turn the ignition off and on again all is fine for a short while.

I'll see the dealer on monday and check the CDI.

 

[shortshooter]

I think you were right Piestore.
The new diagnosis is a leaking Inter Cooler.
So I have been told this is a small radiator type air cooler just behind the front bumper, under the main radiator.
Apparently this is leaking air and thus reducing pressure in the engine.(also messing with the mass air flow sensor)
They say (as you do) that this confuses the transmission.

Up-date on progress in a couple of days.

 

[MB partsman]

oil can travel UP wires... this is not due to pressure, but due to the electic current drawing the oil up.... in effect a magnetic field!

 

[shortshooter]

Up-date.
£500 and a new Inter Cooler Radiator later and I now have full power and kickdown is working again.

But still have a dodgy gear change between 3rd and 4th.
It is a kind of slip into neutral for a second and high revs.
It changes easier if I ease off the gas.

Any possible reasons would be greatly appreciated.
Thanks.
Jon.

 

[shortshooter]

Also there are no faults being recorded.