Mercedes-Benz Forum banner

1 - 14 of 14 Posts

·
Registered
1998 Mercedes-Benz S500
Joined
·
929 Posts
Discussion Starter #1
this is my 1998 W140 S500 n15/3 ecu. car in LHM(Limp Home Mode). can i just clean with som thinner and resolder or ........????????? Any Adias WELCOME. TNKS.
 

Attachments

·
Registered
1997 E320, 1997 S320
Joined
·
2,946 Posts
you can give it a try. clean it with electronic parts cleaner, can buy it from radio shack to any autoparts stores. the connector plug that connects the etc (electronic tranny control module) to the transmission must have been leaking for a long time since the fluid reached the etc. hopefully after cleaning it will still work. sometimes you cannot reset the error codes just with obd2 scanner if they are tranny codes, you would need the mercedes diagnostics machine or carsoft if you have it in order to erase the tranny codes to get it out of limp mode. also make sure you put a new connector plug after you are done, they cost like $10.
by the way everyone with 722.6 tranny needs to check if that connector plug is leaking since it's pretty common. if the fluid leaks to far can reach the etc like in this case.
 

·
Moderator
SL55, 300SE, GL450, Daytona 955i
Joined
·
10,293 Posts
Do what???

what oil and how did it get there?

also, Limp home mode is not triggered by the tranny ECU.
 

·
Premium Member
1998 140.070 CL500, 1966 406.121 U65
Joined
·
1,463 Posts
Do what???

what oil and how did it get there?

also, Limp home mode is not triggered by the tranny ECU.
Bayhas, no offense, but I think you must read up on the working of the 722.6.
Maintenance Hints/Diagnostic Trouble Code Information
It can detect a lot of abnormalities in operation, and put the box into limp-home,
usually in 2nd gear forward and 2nd backward.

ATF oil can creep up the wiring with a leaky connector, by capillary actions, and
all the way up to the control module;
http://www.benzworld.org/forums/w210-e-class/1369000-transmission-fluid-leak-connector-2.html#post2811814

br,
syljua
 

·
Moderator
SL55, 300SE, GL450, Daytona 955i
Joined
·
10,293 Posts
Bayhas, no offense, but I think you must read up on the working of the 722.6.
Maintenance Hints/Diagnostic Trouble Code Information
It can detect a lot of abnormalities in operation, and put the box into limp-home,
usually in 2nd gear forward and 2nd backward.

ATF oil can creep up the wiring with a leaky connector, by capillary actions, and
all the way up to the control module;
http://www.benzworld.org/forums/w210-e-class/1369000-transmission-fluid-leak-connector-2.html#post2811814

br,
syljua
I dont claim to be an expert on 722.6, but what made me make that comment is trannies trigger "protection mode" where the tranny doesnt shift to certain gears, or changes the shift point.

"limp home" mode, is in the ETA, and causes the gas pedal to be 50% lower (shorter... whatever you want to call it), and horse power output to be down to 2/3 by changing the timing.

BTW, protection mode is a feature in 722.5 as well, and if I am not mistaken, it kills the 5th gear.
 

·
Registered
1996 S500 coupe
Joined
·
782 Posts
mine has been weeping for a while now.. didn't realize it could potentially damage the board..

Called up the local dealer and he said he sells a lot of these and knew exactly where it was located and what the part number was .. lol

he said the plug comes with the o ring and it's packaged as a kit for $28

I will change it this weekend and post some DIY pics.

stay tuned
 

·
Registered
1996 S500 coupe
Joined
·
782 Posts
k, I have done a little digging around, and the part # shown in the first post is on top, inside the ecu box beside the blower fan... how does transmission oil get in there??

the part # on the others ide of the plug, from my understanding, is 1402701161 which is also known as an "electrics kit" shown here as per 210 FAQ section:



if that's the case, the whole assembly is inserted in trans. fluid, then how does a leak matter?

I guess I am confused because I am getting contradictory info about the location of this board
 

·
Registered
1998 S500
Joined
·
446 Posts
My understanding is that when the connector you reference is leaking, then ATF works it's way up the cable harness and gets to the module located in the coffin box.

FYI - While the connector is inexpensive, I tried to replace mine without the benefit of a lift by lying under the jacked up car. It was extremely difficult and I ended up having the dealer replace it. Can't recall how much I paid but it was very reasonable.
 

·
Premium Member
1998 140.070 CL500, 1966 406.121 U65
Joined
·
1,463 Posts
"limp home" mode, is in the ETA, and causes the gas pedal to be 50% lower (shorter... whatever you want to call it), and horse power output to be down to 2/3 by changing the timing.
Well, in the first link I gave you, Mercedes call it Limp-Home-Mode for the
transmission also, so I'll stick to that.

br,
syljua
 

·
Registered
1998 Mercedes-Benz S500
Joined
·
929 Posts
Discussion Starter #11
To All

thank you all for your support. keep it up!!!:thumbsup:
 

·
Registered
SEC 600 V12 2dr COUPE (RHD) One of the chosen few.
Joined
·
2,233 Posts
Physicaly its called Wicking..If you dont belive try it with a piece of string and some oil it takes time.. but it will creep up..
 

·
Moderator
SL55, 300SE, GL450, Daytona 955i
Joined
·
10,293 Posts
1 - 14 of 14 Posts
Top