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

The transmission 13-pin connector plug causes most transmission slipping or delayed engagement problems on the Mercedes-Benz 5-speed transmission. “A leaking connector sleeve can allow ATF into the electrical connector and wiring harness. If fluid contaminates the electrical contacts or migrates toward the transmission control module, transmission faults and communication problems can result. This is a common problem on Mercedes-Benz vehicles equipped with the 722.6 transmission. Often, people or even mechanics misdiagnose transmission problems, thinking they need a new valve body or even a new transmission. In many cases, 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 correct the transmission fluid level 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. 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.

 

 

 

 

You also need a 722.6 transmission service dipstick to measure the transmission fluid level because there isn’t one in your car. The transmission has a capped dipstick tube, but most applications do not have a permanent dipstick installed. To measure the transmission fluid level correctly, you need to keep the vehicle level and the engine running. Move the selector through each gear position, return it to Park, and check the fluid with the 722.6 service dipstick at the specified transmission fluid temperature. A precise hot check is made at about 80°C. Do not use driving time alone to estimate fluid temperature. 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 722.6 13-Pin Connector Sleeve and O-Rings.

This video shows how to replace the 13-pin electrical connector sleeve on the transmission. This connector causes transmission oil leaks and gets so wet that the car’s TCU loses communication with the valve body.

Steps:

1. Raise the vehicle only at approved lifting points and support it securely with jack stands or a vehicle lift. Never work under a vehicle supported only by a jack. 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. Loosen the captive 7 mm center screw until the connector sleeve releases. You will need a deep socket or an extension for this. See the picture below.
   
6. Once you remove the bolt, then pull the sleeve straight out.
7. Install the new plug. Make sure it is aligned in the same position as the old one. Seat the sleeve fully and tighten the captive center screw to the Mercedes-Benz specification for the transmission before reconnecting the wiring harness.
8. Reconnect the transmission wiring harness and rotate the locking collar until it is fully seated.
9. Reinstall the heat shield.

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/T CLK500
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 with 722.6 A/T SL320
2003 2004 2005 2006 2007 SL55

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