Help please with intermittent starting problem CLK W209 220CDi

[jrapple]

Here’s hoping someone can point me in the right direction with this:

Always starts if left for a few hours/overnight.

When fault is present, No cold start, Run Flat Indicator unavailable!, Radiator fan runs at full speed and starter will not turn, also my basic code reader will not connect.

Same fault with two keys, but will decide to start randomly, sometimes second turn other times two hours later.

I have wiggled wires and swapped like for like relays in the front SAM and often it will start but cannot pinpoint the fault.

An old invoice from the previous owner shows this fault was rectified with a tin of contact cleaner in 2009!

I have also checked the earth point on the O/S strut top.

I have yet to check voltage on fuse 53 and 54.

How do I get the cover / Plug off the ECU in the SAM box?

Any help will be greatly appreciated.

 

[television]

This is a known fault but I cannot remember what it is, hopefully some will come on that knows it

 

[Steve@Avantgarde]

Normally when the engine fan runs flat out for no reason it has lost communication with the engine control module and the drive authorisation procedure cannot be completed.

It is possible you have a failing/failed front SAM unit.

 

[jrapple]

Update:

Bought myself a Chinese Multiplexer and changed the front SAM, fault still present.

I cleared all the fault codes.

When the car won’t start:
I get B1036 in SAM-F (5.5v at Connector 18, Terminal 61)

also I cannot connect to CDI_UP (Warning Earlier programming was not performed completely and successfully)

However when the car has cooled I can connect to CDI_UP and no faults or info is stored. I have completed an alternator test from here and that passed.

Any more thoughts before I send the CDI unit for test possible repair?

 

[Mark@RMK]

it will be the ECU

Changed a load of them!

If you send it off, expect to get it back with a " We've fixed it charge" and it still do the same thing! There is a mcu on the board which fails but NEVER seen one fixed affectively or at all for that matter!

Find a Used unit, or buy a new unit from MB! (You will need to send the used ECU to a reputable company for unlocking, or coding )

Mark

 

[Angeloj]

it will be the ECU

Changed a load of them!

If you send it off, expect to get it back with a " We've fixed it charge" and it still do the same thing! There is a mcu on the board which fails but NEVER seen one fixed affectively or at all for that matter!

Find a Used unit, or buy a new unit from MB! (You will need to send the used ECU to a reputable company for unlocking, or coding )

Mark

That's not gonna be cheap!!

 

[jrapple]

Thanks for your help, hope it’s not against board rules but can anyone recommend a reliable company for reprogramming a second-hand unit, will they “copy” my unit so it’s good to go, looks like I can set injectors etc. with my multiplexer. Your help is much appreciated.

 

[Mark@RMK]

You could check out my section of this forum maybe?

Big banner below!

I can set it up either way. Plug and play or you can code it in, using control unit adaptations and drive authorisation teach in!

Very easy to do with STAR! No SCN coding or anything else as I leave it inside the data of the ecu!

Mark

 

[jrapple]

Fixed!

After speaking to Mark@RMK I bought a second hand ECU and visited him in Birmingham, He cloned the ECU with data from the failing unit, keeping the identity, mileage and cars history.

The problem is now long gone and for half the price of a new ECU I have a repaired car and a Star Diagnostics Kit.

Thanks to all on this forum, if you have electronic related problems I highly recommend mark@RMK.