ECU Pain!

[marknexus]

Can anyone please advise who is would be a good company to talk to regarding testing / repair of an A class ECU?

Also, having just changed a faulty starter motor for replacement, I have been advised that there are 2 types of motor (both physically interchangable) but electrically diferent such that if fitting a different unit to the one originally fitted it can blow up the ECU.

Can anyone please confirm if this is correct? If it is, I find it mind boggling stupid on behalf of Mercedes!! And very very very frustrating!!

Help!

M

 

[television]

I will take a read up shortly on this for you, though SAM or the like is better than me

 

[BlackC55]

That is correct.

Some have a seperate starter relay and some are operated whthin the ECU.

 

[marknexus]

ARGH!!

how can i tell the difference, if that isnt a daft question?

The unit i fitted looks similar - in fact the solonoid looks identical, which is the componet (i imagine) that would be operated by either the ECU or the relay. its just the motor itself is long and thin on the old broken assy and the new one is a bit shorter and fatter...

There is no relay that i can find in the car that operates the starter (and i have tried!)

M

 

[television]

Can I just have the details of the car please, the first 6 VIN numbers would be best after wdb

 

[marknexus]

Hi!

Really appreciate your help here.

VIN

WDB 1680322J689504

Thanks so much!!

M

 

[television]

See what I have and I will post back

 

[television]

You have a K6 starter relay in both versions even after the change in 01-09-01

In both versions there are 2 fuses that feed the K6 relay, a 2A and a 8A known as F1

Still looking for more info

 

[marknexus]

Thanks so much!!

 

[television]

On the remove starter and refit it says that all stored faults must be erased and it looks as though there could be a few.

The actual words are.

When the work is complete stored faults must be worked on in the diagnostic trouble memories and erased

 

[GCLTuning]

Correct all codes must be cleared - I thing blowing up the ECU is a bit drastic it may harm the Eprom ect ect but this is cheap as chips LOL £5.00 a beer and a good technician :lol:

Regards GCL Tuning

 

[marknexus]

Thanks very much for all your help!

One question - clearing the fault codes how can i do this if the car doesnt start and drive to a merc garage.

Can the codes stop the engine starting in the first place?

M

 

[marknexus]

Ok, having spent several more hours (this time in the snow) trying to make some sense of things, im about ready to set the damn car on fire! GRRR!!

I cannot find any K6 relay. Its not in the battery box (4 relays K 7 to 10) and not in the engine bay control module box with the ECU only got 3 relays fitted, seemingly K1, K2.0/2.1 and K5. I have pulled out all the foam and there is defiantly only 3 relays that I can see.

Also, some of the colour colded wires jsut dont seem to follow the diagram i have.

???


Does any one know where i can get the actual wiring diagram for my car instead of the generic one in the haynes book.

thanks again for any help offered!

M

 

[television]

I have the wiring diagram that I can send, but I cant print what all of the things are.

I am looking for the location of the K6

 

[marknexus]

Hey thanks for helping!!!

It is so so so frustrating...

I guess its a function of there being so many varients for all the different countries etc etc..

in my car f2 is a 15 amp fuse and the paper work in the car says its for Gas ECU, Fuel Pump relay (coil), Ignition coils, and starter lock out(only in Brazil)

F8 is 30amp fuse and is dsecribed as starter relay (diesel), starter relay (only in Brasil)

the paper work also says that the K6 relay should be located underneath the k2.0/2.1. in my car there is just a big lot of fresh air!

i really dont thnk i have a starter relay...

Also the only mention of a starter relay is either for diesel or only in Brasil!

If so, then the ECU must do the switching or its the conventional means of the ignition swich being directly connected to the starter solenoid...

either way im clueless cos i dont have the specific diagrams..

M

 

[television]

I have looked at the whole thing,there are only two diagrams both show a K6 but I have spent 1 hour looking for it

I am looking at the 168032 with the 166 engine

 

[television]

I can send you the wiring diagram, and ring you and you can mark in things as to what they are

 

[television]

I have found where it is and have the details that I can send to you

 

[RonH]

http://www.aclassinfo.co.uk/mypage.1.htm
Hi,
there seems to be some interesting articles on this web site for the A-Class. Maybe something on there to help you with your problem.
Ron H.

 

[marknexus]

Thanks guys! I have had a look at that website and it is useful but still cant help me find the K6!!

Malcolm - really appreciate the time you have spent on this!!! really very kind!

how can you send me the details? can you send me an email or how do i ring you?

Thanks again!

M