2001 S430 Transmission Repair
Thread Starter
Junior Member
Joined: Nov 2011
Posts: 48
Likes: 5
2008 S550
2001 S430 Transmission Repair
Hello all!
Well I have read through this site and have come across numerous DIY's to the repair of the "transmission stuck in limp mode". My poor baby has been sitting for over a month in my garage due to this reason and I have made my mind up to repair it myself. I have gone through all the socket cleaning routines and have had no luck.
I am mechanicly inclined (complete engine overhaul of a grey market 1986 190 2.3-16 with great success). My experience with automatic transmissions is limited but need to dive in head first.
I do not have a scanner but I will get one soon but all of my problems seem to point to the conductor plate so that is what I am about to change. My car is a 2001 S430 sport with 150 000 miles and the is no indication of excesive wear on the plates and no slipage. The gear changes were always smooth but the car would go into limp mode every now and then and stay in the last good gear. It would reset after switching of the ignition. Now it is in second and will not come out. Checked for leaks and found a little oil in the 13 pin socket (not excesive but a little wet). Replaced the o-ring and cleaned it out but still stuck in second.
Before I start this process I have a few questions to the members of this forum.
How many miles do you member think I have left on this tranny? Is it worth the effort of replacing the conductor plate only to have the tranny fail in say 10 000 miles? I can get a rebuilt 1 for 3K but am a little concerned for quality. Mercedes wants 7K plus. Hmmmm. I do not have the facility to drop the tranny here so what else do I do? She is a beautifull car and I would hate to let her stand here.
Any input would help.
Well I have read through this site and have come across numerous DIY's to the repair of the "transmission stuck in limp mode". My poor baby has been sitting for over a month in my garage due to this reason and I have made my mind up to repair it myself. I have gone through all the socket cleaning routines and have had no luck.
I am mechanicly inclined (complete engine overhaul of a grey market 1986 190 2.3-16 with great success). My experience with automatic transmissions is limited but need to dive in head first.
I do not have a scanner but I will get one soon but all of my problems seem to point to the conductor plate so that is what I am about to change. My car is a 2001 S430 sport with 150 000 miles and the is no indication of excesive wear on the plates and no slipage. The gear changes were always smooth but the car would go into limp mode every now and then and stay in the last good gear. It would reset after switching of the ignition. Now it is in second and will not come out. Checked for leaks and found a little oil in the 13 pin socket (not excesive but a little wet). Replaced the o-ring and cleaned it out but still stuck in second.
Before I start this process I have a few questions to the members of this forum.
How many miles do you member think I have left on this tranny? Is it worth the effort of replacing the conductor plate only to have the tranny fail in say 10 000 miles? I can get a rebuilt 1 for 3K but am a little concerned for quality. Mercedes wants 7K plus. Hmmmm. I do not have the facility to drop the tranny here so what else do I do? She is a beautifull car and I would hate to let her stand here.
Any input would help.
Super Member
Joined: Oct 2011
Posts: 933
Likes: 25
2004 CLK 500
I read on here that these transmissions can be had all day long rebuilt for $1,300 at many tranny shops.. obviously you will have to put it in, but that shouldn't be too hard.. I have been told these trannys are very sturdy.. I see ML430's which are all 4matic with 200k+ miles and running strong so I would think if your tranny hasn't been nuetral dropped and picked on in general it should be okay.. but you will never know for sure.. How hard is a conductor plate swap? I thought it was fairly easy.. it only takes ten minutes to replace the switch, but sounds like you have already taken care of that part..
Newbie
Joined: Mar 2018
Posts: 4
Likes: 0
2001 s430 w220 engine 722.6 tran
Limp mode
My 2001 s430 transmission is stuck in limp mode. I changed trans oil, filter, gasket, conductor plate,13pin plug o rings, and also cleaned tcm. These were procedures I have learned from the forum to geg it out of limp mode. Nothing worked so far. The only thing I havent checked yet is the speed sensors. Since all other possibilities have been eliminated, should I focus on the sensors now?
MBWorld Fanatic!
Joined: Jan 2008
Posts: 6,150
Likes: 533
Mercedes
My 2001 s430 transmission is stuck in limp mode. I changed trans oil, filter, gasket, conductor plate,13pin plug o rings, and also cleaned tcm. These were procedures I have learned from the forum to geg it out of limp mode. Nothing worked so far. The only thing I havent checked yet is the speed sensors. Since all other possibilities have been eliminated, should I focus on the sensors now?
Trending Topics
Newbie
Joined: Mar 2018
Posts: 4
Likes: 0
2001 s430 w220 engine 722.6 tran
The tcm was full of fluid and there was a blown capacitor on the the board. I even replaced the capacitor and double checked the connections on the board. The wires are definitely contaminated and I will try to address that before i buy new sensors. I heard of one guy who used cimpressed air through the 13pin connector and pushed enough fluid out that his limp mode was corrected. I will update you guys on my progress.
2 other issues, radiator fan is dead and headlight switch does nothing when I turn it on. Any thoughts?
2 other issues, radiator fan is dead and headlight switch does nothing when I turn it on. Any thoughts?
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
MBWorld Fanatic!
Joined: Jan 2008
Posts: 6,150
Likes: 533
Mercedes
The tcm was full of fluid and there was a blown capacitor on the the board. I even replaced the capacitor and double checked the connections on the board. The wires are definitely contaminated and I will try to address that before i buy new sensors. I heard of one guy who used cimpressed air through the 13pin connector and pushed enough fluid out that his limp mode was corrected. I will update you guys on my progress.
2 other issues, radiator fan is dead and headlight switch does nothing when I turn it on. Any thoughts?
2 other issues, radiator fan is dead and headlight switch does nothing when I turn it on. Any thoughts?
you might need to change the tcm and wiring harness
Newbie
Joined: Mar 2018
Posts: 4
Likes: 0
2001 s430 w220 engine 722.6 tran
Once I change the tcm will I have to hook it up to a STAR scanner and have it programed? Also I was told that once I remove the 13pin plug with the battery still connected it automatically sends the car into limp mode bc of the code it throws when the plug is disconnected from the trans and I have to have the codes cleared with the proper scanner to get it out of limp mode. Is this true?
