722.629 tranny issue.
#1
Super Member
Thread Starter
Join Date: Dec 2011
Location: Oregon
Posts: 549
Likes: 0
Received 0 Likes
on
0 Posts
'97 c36
The car is now at 230k miles and it had it's first transmission issue. Driving down the road 70 mph in overdrive fine. Come to a stop for a off ramp light and the car is locked in what I'm assuming 2nd possibly 3rd.
Shifting into different gears on the selector and no response from the transmission. Pull over and shift it into neutral which works, but putting it back into drive the car jerks kinda hard. Shift it back into neutral then selected reverse and it almost seemed like it engaged for a split second then nothing.
So I put it back in drive and nothing. I had no working gears in either direction and no trouble lights on dash.
I selected park, turned off and then restarted the car and everything was back to normal. Drove the car this morning and seems perfectly fine. Plan is to lift the car and check for anything obvious like a loose/leaking connector. I'm going to check the trans controller connection for corrosion as well as the fluid level.
But anything else I should check?
Shifting into different gears on the selector and no response from the transmission. Pull over and shift it into neutral which works, but putting it back into drive the car jerks kinda hard. Shift it back into neutral then selected reverse and it almost seemed like it engaged for a split second then nothing.
So I put it back in drive and nothing. I had no working gears in either direction and no trouble lights on dash.
I selected park, turned off and then restarted the car and everything was back to normal. Drove the car this morning and seems perfectly fine. Plan is to lift the car and check for anything obvious like a loose/leaking connector. I'm going to check the trans controller connection for corrosion as well as the fluid level.
But anything else I should check?
Last edited by Super B; 12-13-2014 at 12:41 PM.
#2
MBWorld Fanatic!
These trannys only have P, R, N, D. The rest is really all electronic so first thing id do is reset it. Try leaving the battery disconnected for 15 minutes. Do not close your trunk tho
#3
MBWorld Fanatic!
Join Date: Aug 2006
Location: A.D., U.A.E
Posts: 7,001
Likes: 0
Received 377 Likes
on
342 Posts
00 C200 & 00 C55 & 06 SLK55
Prefer to diagnose the car first, codes will tell,,
mostly; bad TCU or bad speed sensor in conductor plate could cause this issue, as a "limp mode or limp home"...!!
ZAYED,,
mostly; bad TCU or bad speed sensor in conductor plate could cause this issue, as a "limp mode or limp home"...!!
ZAYED,,
#4
Member
Join Date: Nov 2013
Location: Virginia Beach
Posts: 172
Likes: 0
Received 1 Like
on
1 Post
1995 AMG C36
My car had some issues, turns out it was some wires corroded and when I would go to start sometimes it would not start unless I put it in N. Pretty sure they were shorting out against the casing of the transmission.
I simply fixed the wires and so far no issues since.
If you have a way to scan your TCU for codes do that before you reset the TCU, most likely it will come back again unless the issue is corrected.
I simply fixed the wires and so far no issues since.
If you have a way to scan your TCU for codes do that before you reset the TCU, most likely it will come back again unless the issue is corrected.
#5
MBWorld Fanatic!
Join Date: Mar 2010
Location: Land of mountains, cheese, chocolate and watches
Posts: 5,647
Received 251 Likes
on
212 Posts
12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG sold)
I would check the ATF level and if the tranny has not had some new "vitamins" to chew recently; I would get a full flush and filter change done. Check what comes out of the drain hole (metal shavings, etc.). It can't do any harm and use only a top ATF recommended by MB and certainly no snake oil.
#6
Super Member
Thread Starter
Join Date: Dec 2011
Location: Oregon
Posts: 549
Likes: 0
Received 0 Likes
on
0 Posts
'97 c36
Thanks for the replies, yeah checked the level it was fine. Changed the fluid and filter 30k ago so it's getting close to a service. I'll look into this more this weekend. A buddy is letting me borrow a sd connect c3 hopefully I can get some data with that. I've been driving the car and seems totally normal but you know how those problems go.
Depending on how well the c3 works it might be time just to buy one. Kinda looking forward to trying it out first.
Depending on how well the c3 works it might be time just to buy one. Kinda looking forward to trying it out first.
Trending Topics
#8
Super Member
Thread Starter
Join Date: Dec 2011
Location: Oregon
Posts: 549
Likes: 0
Received 0 Likes
on
0 Posts
'97 c36
No sorries needed. Here is a link for some reading. http://www.obd2inthebox.com/mb-star-...FYqIfgod2joA7w It's a multiplexer that let's you connect the engine control module to your laptop. With it and some software you can pull the codes and diagnose/test certain systems in our old mercedes. There is a newer model ( c4 ) that connects wirelessly to your laptop and has a display. It's more money but Chinese copies can be found on eBay pretty easily with software.
#9
Super Member
Thread Starter
Join Date: Dec 2011
Location: Oregon
Posts: 549
Likes: 0
Received 0 Likes
on
0 Posts
'97 c36
Well I borrowed the reader and I'm having a hard time getting it to read. For some reason the multiplexer can not connect to the car. I have a power light on the multiplexer and I can get into the command prompts for the multiplexer . But when I try to get it to communicate with the car I get this same error prompt.
I've tried it in key positions one and two.. I've re seated all the connectors. I'm using the obd2 cable. But no luck. The guy who let me borrow this laptop is going to meet up tomorrow and give it a try he said he never had and issue. Any of you guys had this problem? The obd2 port works with a craftsman scan tool so I'm reasonably sure the port is working.
I've tried it in key positions one and two.. I've re seated all the connectors. I'm using the obd2 cable. But no luck. The guy who let me borrow this laptop is going to meet up tomorrow and give it a try he said he never had and issue. Any of you guys had this problem? The obd2 port works with a craftsman scan tool so I'm reasonably sure the port is working.
#11
Super Member
Thread Starter
Join Date: Dec 2011
Location: Oregon
Posts: 549
Likes: 0
Received 0 Likes
on
0 Posts
'97 c36
Sooo update on this if anyone gives a crap. For the 97 cars you can't used the obd2 port for star. You have to plug the multiplexer into the round port on the ECU/TCU box with the round locking cable to get it to work..
After figuring that out I dug into the codes and sure enough it was the speed sensor giving the fault. So down she comes. The job over all is pretty straight forward and there is an excellent video on you tube showing you how to do this. As you can see from the pictures the front speed sensor had cracked open in multiple spots and transmission clutch/plate deposits had made their home there..
Plate in and oil fill with max life atf (I know I'm probably going to get bombed for that but it does meet the MB spec for the nag 1 transmissions so figured I'd give it a try) car drives and shifts great. Might be in my head but seems like a shifts faster than before.
244k miles and climbing....
Cracked sensor
After figuring that out I dug into the codes and sure enough it was the speed sensor giving the fault. So down she comes. The job over all is pretty straight forward and there is an excellent video on you tube showing you how to do this. As you can see from the pictures the front speed sensor had cracked open in multiple spots and transmission clutch/plate deposits had made their home there..
Plate in and oil fill with max life atf (I know I'm probably going to get bombed for that but it does meet the MB spec for the nag 1 transmissions so figured I'd give it a try) car drives and shifts great. Might be in my head but seems like a shifts faster than before.
244k miles and climbing....
Cracked sensor