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MB Paul
MB Paul, Mercedes Technician
Category: Mercedes
Satisfied Customers: 4317
Experience:  Mercedes Benz Qualified Diagnostic Technician
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I have a year 2000 Mercedes SLK230 Kompressor. I have had the

Resolved Question:

I have a year 2000 Mercedes SLK230 Kompressor. I have had the transmission fluid changed as well as filters and gaskit by a mechanic who used Mecedes dipstick. The problem is it drove in all gears for about 10 miles then when I went into triptronic it got stuck in 3rd. I turned off the engine hoping it would reset but it only went into 1st and would not go through the other gears and could not select any of the other gears in any box except reverse and drive in 1st gear.

I would be grateful if you could help me with this problem.
Submitted: 3 years ago.
Category: Mercedes
Expert:  MB Paul replied 3 years ago.

MB Paul :

Hi - this is a problem with the transmission going into limp mode. This happens when the transmission control unit detects certain faults & to diagnose correctly will need a diagnostic tool that can read the faults stored in the transmission ECU. In the first instance however I would recommend checking the electrical connector on the side of the transmission to see if this has been disturbed during the recent work carried out - try disconnecting & cleaning the connector with electrical cleaner, also checking for any signs of transmission fluid inside the connector.

MB Paul :

If transmission fluid is leaking into the connector then the plastic spacer insert with seals should be replaced that is located in the tranmission casing that the connector plugs into.

MB Paul :

After this a check for fault codes will be required to pinpoint the fault.

MB Paul :

Problems with the speed sensors on the electrical plate inside the transmission are common on this model.

MB Paul :

A check for leaks & rechecking the transmission oil level would also be a good idea at this stage

MB Paul :

Best regards, Paul

Customer:

Hi,

Customer:

Hi, Are the speed sensors easy to replace if the problem lies in these sensors and are they expensive? Shaun

MB Paul and other Mercedes Specialists are ready to help you
Expert:  MB Paul replied 3 years ago.
Hi Shaun,

The speed sensors are located on a complete electrical plate that sits on top of the valve body - replacement requires the valve body to be removed from the transmission. Its not too difficult for a competent mechanic to do this.

From memory I think the electrical plate costs around £200 - you should also replace the electrical spacer I mentioned as this needs to be removed. Usually we would change the oil & filter & sump gasket also but you may want to use these again as you have just replaced these.

Best regards, Paul