DIY Replace Transmission Connector Adapter Plug O-rings Mercedes Benz 722.6

The transmission 13-pin connector plug causes most transmission slip or delayed engagement problems on the Mercedes Benz 5-speed transmission. It leaks transmission fluid to the 13-pin connector and causes the car to lose communication with the valve body. This is a common problem with the Mercedes Benz cars from 1998 to 2008. Often, people or even mechanics misdiagnose transmission problems, thinking they need a new valve body or even transmission. When in reality, the problem is the transmission connector plug leaking oil at the rubber O rings. So before you do anything else to your car, replace this plug and add transmission oil first to eliminate this common problem. It is a simple task you can do yourself.

Parts Needed

Current Part Number  2035400253 – A/T Plug Adapter (Conductor Plate Connector) – $15

OLD  1402700250 – A/T Plug Adapter (Conductor Plate Connector)
This famous transmission plug leaks oil and causes most transmission problems (heart attacks). You can get it on Amazon for less than $15; see here for the original part. Replacement part # A2035400253

 

 

 

 

 

 

You will also need to add transmission fluid once you remove the plug. The transmission will show signs of slipping, hard shifting, or delayed engagement when it is low on fluid. This is the correct fluid which you can also order from Amazon here.

 

 

 

 

It would be best if you also had the transmission dipstick to measure the transmission fluid level because there isn’t one in your car. The tube is there with a cap on it but with no dipstick. To measure the transmission fluid level correctly, you need to drive the car for about 5 minutes and then measure the level as the transmission fluid needs to be warm when you measure it. It sells on Amazon for about $15; see here.   Mercedes Benz Transmission Dipstick reference number 140-589-1521-00.

 

 

 

How to replace the 13-pin plug, aka the famous transmission O rings. 

This video shows how to replace the famous 13-pin connector plugging into the transmission valve body. This connector causes transmission oil leaks and gets so wet that the car TCU loses communication with the valve body.

Steps:

1. You may remove the plastic cover to get to the connector.
2. Remove the Torx bolt at the bottom of the metal shield.
3. Twist the connector down. 
4. Pull the cable out and see if there is oil at the pins.
5. Remove the 7 mm bolt in the center of the famous connector. You will need a dip socket or an extension for this. See the picture below.
   
6. Once you remove the bolt, pull the old plug straight out.
7. Install the new plug. Make sure it is aligned in the same position as the old one.
8. Push the transmission wire harness back in there and twist the tab up.
9. Install the heat shield cover back in.

Here is another video to help you with replacing the transmission plug.

 

 

Applications

Part Number 2035400253 , 2035400153 , 2035400053 , 1402700250 , 203 540 02 53 , 203 540 01 53 , 203 540 00 53 , 140 270 02 50

Mercedes Transmission Conductor Plate Connector Adapter Genuine OE 722.6

1997 1998 1999 2000 2001 2002 2003 2004 2005 w/ 722.6 A/T C230
2001 2002 2003 2004 2005 w/ 722.6 A/T C240 C320
2004 2005 2006 2007 w/ 722.6 A/T C280
2002 2003 2004 w/ 722.6 A/T C32 AMG
2006 2007 w/ 722.6 A/T C350
1995 1996 1997 w/ 722.6 A/T C36 AMG
1998 1999 2000 w/ 722.6 A/T C43 AMG
2005 2006 C55 AMG , CL65 AMG
1998 1999 2000 2001 2002 2003 2004 2005 2006 w/ 722.6 A/T CL500
2001 2002 2003 2004 2005 2006 w/ 722.6 A/T CLK55 AMG , CL55 AMG
1998 1999 2000 2001 2002 2003 2004 2005 2006 w/ 722.6 A/T CL600
1998 1999 2000 2001 2002 2003 2004 2005 w/ 722.6 A/T CLK320
1999 2000 2001 2002 2003 w/ 722.6 A/T CLK430
2000 2001 2002 2003 2004 2005 2006 w/ 722.6 A/TCLK500
2006 CLS55 AMG / 1996 1997 1998 1999 w/ 722.6 A/T E300
1996 1997 1998 1999 2001 2002 w/ 722.6 A/T E320
2003 2004 2005 2006 w/ 722.6 5-Speed A/T E320
2006 2007 w/ 722.6 5-Speed A/T E350
2003 2004 2005 2006 w/ 722.6 5-Speed A/T E500 / 1997 w/ 722.6 A/T E420
1998 1999 2000 2001 2002 w/ 722.6 A/T E430
1999 2000 2001 2002 w/ 722.6 A/T E55 AMG
2003 2004 2005 2006 w/ 722.6 5-Speed A/T E55 AMG
2002 2003 2004 2005 w/ 722.6 A/T G500
2003 2004 2005 w/ 722.6 A/T G55 AMG
1998 w/ 722.6 A/T ML320
1999 2000 2001 2002 w/ 722.6 A/T ML320
2003 2004 2005 w/ 722.6 A/T ML350
1999 2000 2001 w/ 722.6 A/T ML350
2002 2003 2004 2005 w/ 722.6 A/T ML500
2000 2001 2002 2003 w/ 722.6 A/T ML55 AMG
1994 1995 1996 1997 1998 1999 w/ 722.6 A/T S320 S420 / 2006 w/ 722.6 A/T S350
2000 2001 2002 2003 2004 2005 2006 w/ 722.6 A/T S430
1994 2005 2006 w/ 722.6 A/T S500 S600 SL500
2001 2002 2003 2004 2005 2006 w/ 722.6 A/T S55 AMG / 2006 w/ 722.6 A/T S65 AMG
1994 1995 1996 1997 w/722.6 A/T SL320
2003 2004 2005 2006 2007 SL55