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Hello! I bought my 1996 S600 last year with a transmission problem. Sometimes the car would not shift from 2nd to 3rd properly: the RPMs would rise to over 3K and then it would shift really hard. So I would let go off the gas pedal and it would shift pretty much ok. I drove it that way for about 1K miles being gentle on that 2-3 shift.

A few months ago I replaced the conductor plate and the connector adapter. I used Pentosin 1088206 1LV ATF and filled it to proper level. One of the speed sensors on the plate was cracked. I took it for a test drive and it felt like it drove fine for a few miles and then the hard shift problem came back.

After a few dozen miles the transmission went into the limp-home mode. The fault codes were 055 and 151. I did some more research on this forum and checked my pressure regulator spring and found it broken into 3 pieces. After replacing it and clearing the codes took it for a test drive. Again at first it felt fine but after a few miles it went back to limp mode. I got home turned it off, pulled the same 055 and 151 codes and lost communication with the EGS (TCM). Also, after restarting the car the transmission would not shift into any gear (it seemed as if it was always in neutral).

The next day I started the car and it shifted into forward and reverse gears just fine and of course went into limp home with the same 055 and 151 codes after a few initial shifts. But the DLC connection was flaky. I pulled the EGS (TCM) and it was clean - no any signs of ATF in it. But I noticed one of the electrolytic caps near the DLC pin has leaked. I removed both caps, cleaned the board, put new caps on and patched damaged via. The DLC EGS connection now is fine. Unfortunately after clearing the codes it did the same thing - it shifted fine all the way to 4th gear but then went into limp mode and after downshifting to 1st at the intersection it went into neutral. Turning off the car, waiting and starting it up again didn't help. I disconnected EGS module, connected it back and got it to go into gear. This same neutral problem happened a few more times while testing other things (input speed sensors, wheel speed sensor readings, etc). Every time disconnecting power to EGS module would bring back shifting to 2nd (limp mode) gear. By the way, I checked solenoid resistances which are ok, I checked power to input speed sensors, which is fine, I checked voltage from speed sensors which is about 2.6-2.9V when car is idling and it's probably OK since they produce square wave signal. Also, voltage to solenoids is fine once the codes are erased and of course it's cut off when EGS is in limp mode. The only thing I found out of spec was the resistance across CAN bus L-H pins of EGS. Apparently it's supposed to be 50-100 Ohms and mine is reading 39K Ohms.

Today I checked my transmission without EGS and it nicely engages forward and reverse gears (limp mode). So I think I probably need to get a new EGS module. And here is my question. My EGS part number is 017 545 04 32. Would any EGS (let's say 1996 E320/420) with the same part number work in my S600? I also noticed that in 1997 and later cars the EGS had different part number: 017 545 07 32. I think it's because MB went to touch shift gear selector but I am not sure. Would that EGS work? Also, I believe I will have to SCN code it to my car. How is it done? I do have DAS. Thanks for your help!
 

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Welcome to Benzworld !!

Thank you for your detailed post, and I'm sorry for your problems...

You have done the correct things, and having DAS is smart too...

What is the date of manufacture of your car as I see from your picture of the open EGS is it is the wrong year... The 96 and early 97 cars the EGS EPROM software was on a PLCC socket(the square chip with light yellow paper tag). Late 97 through 99 were soldered directly like yours.

What pins did you measure the CAN bus resistance from?

Did you power up the solenoids by themselves hear the click?

1996 was the goofy year for the 722.6, and the transmission is not compatible with other years, nor is the EGS...

The puffy capacitor can be from a jump-start, or the three power transistors that surround it.

Do you mind sharing your vin to see what EGS it takes?

Martin
 

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Discussion Starter #3
Thanks, Martin!

I don't have manufacturing date with me right now but I will post it later. The VIN is WDBGA57EXTA308123.

I don't think the CAN bus pins are numbered but they are marked L,H. They are the ones all the way to the side on the connector that has lines for solenoids and speed sensors.

I didn't test the solenoids yet. I will do it next time I play with it.

Although it may look that way the capacitor was not puffy at all. It looked normal but it leaked on the bottom. I thought it was probably due to age although usually these caps would dry out.

I do have most of the maintenance records for the car since 30K miles. It has been maintained by the reputable local MB shop. They performed transmission flush at 90K miles and it's possible they swapped out the EGS. Previous owner of the car knew these transmissions were "sealed for life" so I wonder whether the shifting problem really started around that time and flushing was an attempt to fix it.

Do you by any chance know where I could find one of these EGS computers? Do you think another one from 1996 car such as E420 would work? Do you think this one Mercedes-Benz W140 300SE 300SEL transmission control module EGS 017 545 04 32 | eBay would work? Thanks a again!

- Petras
 

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Let me reply to your thread later, but for starters a six-cylinder EGS will not work, and one from late 97 will not work either...

My understanding(from the aftermarket transmission re-builders) is a V8/V12's are the same, but I have not contested that yet, but you need to stay with 96 to mid 97..

Martin
 

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Discussion Starter #7
Martin, I really appreciate your help! But now I am even more confused. The diagram is showing 017 545 05 32 for EGS but my module box (the coffin) looks quite different (my DLC connector is on the wheelwell so I don't have that round cap and the box is shaped more like a boat). I called my local dealer and they said my part number 017 545 04 32 is correct for my VIN. So I think my best bet is to try finding 1996 S500 EGS.

One last question. Do I have to SCN code replacement unit or just drop it in and hopefully go :)? Thanks again!

- Petras
 

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Petras,

You are welcome

I need to look at my stash of EGS modules, but I know I have a one V12, and many V8's

They are not SCN coded, so you can find a used one. Clear it and go...

Martin
 

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Discussion Starter #9
Martin, if you would like to sell one either from S600 or S500 I am interested. Just PM me. Again, thanks a lot!
 

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Pec,

I'm near you. What shop? There is a new shop out there, 2 MB master techs, both trained and won awards in the 90s. They know our cars. Literally jumped ship from another Big Indie and just opened. They are fixing the doors, seat belts, and wind noise on my coupe, as well as a few other minor items. Suspension is next up for me. They work on the 722.6 there as well, including full swaps. They will give you a good price. PM me for info if interested.

My car has 179k and based on the cryptic VMI printout (no hard copies of service records available), it appears to have had the fluid done 3 times since 50k. It has some slight clunky shifting from 3-4 and did a weird "slam" in W mode going from 2-3. I experienced the same years ago on my 202. Was thinking about doing a (4th?) fluid drain, conductor plate, and replacing the spring you mentioned. Also toying with the idea of leaving it be, since it may need a rebuild by 200k anyway (how many miles can a .6 suffer the v12 torque regardless of how fresh the fluid is?)
 

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Will_c140,
Thanks, but I enjoy working on my cars myself. My S600 for the past 10 years (from 30K miles) was serviced by "A Better Wrench" in Chapel Hill, NC. Previous owner was very meticulous and saved all maintenance records. Which by the way dispels the myth that S600 cars are very expensive to keep running. During past 10 years he spent on average maybe $1K in maintenance and that's by doing everything at that shop.
I do think I am very close to solving this transmission issue since with my current EGS computer I keep loosing DAS connection when trying to read EGS live data. It also keeps going into neutral and disabling limp home mode until I disconnect and connect it back. If I remove it completely the transmission works correctly - no neutral problem and it's in limp home mode all the time. I am currently searching for good used EGS module. I called "A Better Wrench" a few days ago and according to their parts guy I need one from S600. I don't buy that and will try one from S420 or S500 whichever comes by first.
 

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If you've got the inclination, by all means use it and save money.

I can't solve your issue but I will say that I agree, after fixing coils and driving this car for a couple thousand miles, it's no different than my m119 from a "sense of reliability" standpoint, it just does its job, no drama, like any Benz of the era. Coupe body and interior hardware is another story, sort of like top hydraulics on an SL....
 

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The transmission issue is finally fixed! It turned out to be old o-rings on the 3-4 shift solenoid. Apparently when I replaced conductor plate the old o-rings got disturbed and for that one solenoid it no longer provided sufficient seal. Thus when EGS tried to shift to 4th gear the transmission would not shift and the EGS would report 055 and 151 fault codes (Gear comparison negative. Target gear not achieved) and would go into limp home mode.

Since MB does not sell these o-rings and I did not want to buy $90 transmission seal kit from my local Transtar store I ended up getting a few different size metric Buna-N 90 o-rings from theoringstore.com. The ones that worked were 2x5mm and 2x12mm for shift solenoids and 2x12mm for TCC solenoid. Actually the same o-ring also works well for motor oil dipstick (mine was very hard and no longer sealed). So ordering 5 of those was a good idea.
 

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How about that!

The transmission issue is finally fixed! It turned out to be old o-rings on the 3-4 shift solenoid. Apparently when I replaced conductor plate the old o-rings got disturbed and for that one solenoid it no longer provided sufficient seal. Thus when EGS tried to shift to 4th gear the transmission would not shift and the EGS would report 055 and 151 fault codes (Gear comparison negative. Target gear not achieved) and would go into limp home mode.

Since MB does not sell these o-rings and I did not want to buy $90 transmission seal kit from my local Transtar store I ended up getting a few different size metric Buna-N 90 o-rings from theoringstore.com. The ones that worked were 2x5mm and 2x12mm for shift solenoids and 2x12mm for TCC solenoid. Actually the same o-ring also works well for motor oil dipstick (mine was very hard and no longer sealed). So ordering 5 of those was a good idea.
When I was preparing to change my conductor plate I was very concerned about re-using the solenoid o-rings ~16 years old at the time. But as you correctly stated they were not available separately (they are supplied with a new replacement solenoid). I asked around and NOONE ever changed the solenoid o-rings associated with with changing the conductor plate. I thought it was odd and risky and took the plunge. fortunately i was lucky and all worked out well....she shifts perfectly.

How in the world did you deduce it was the solenoid o-ring leaking for root cause of the the problem you were having? "when EGS tried to shift to 4th gear the transmission would not shift and the EGS would report 055 and 151 fault codes (Gear comparison negative. Target gear not achieved) and would go into limp home mode."

Seth
 

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Discussion Starter #15
While working on my transmission problem I made a few interesting discoveries:

1. If you cannot communicate to your EGS module or the communication link breaks while you are driving with the DAS connected (viewing live data) you most likely have a problem with EGS. Mine had leaked out capacitors and was working only intermittently. So DAS would sometimes connect, sometimes would not connect, I would loose communications while driving with DAS in EGS live mode, etc.

2. The EGS has to be Version coded for your car. So assuming my computer was bad (it actually wasn't once I replaced the caps) I purchased a few EGS modules on Ebay making sure they had the same part number as my original module. I asked sellers what cars those modules came from and they could not tell it. Connecting those modules to my car resulted in EGS fault code 147 (Gear implausible or transmission slipping). That actually makes sense because EGS compares transmission speed sensor data to ABS speed sensor data to determine the gear the transmission is in. If transmission gear ratios, rear differential or wheel sizes on those other cars were different from mine the comparison would not be correct. While looking up EGS Control Unit Version I noticed the ETC coding value was different on my original EGS than that of Ebay unit (f23 vs f25). I also noticed Version Coding function in DAS which allows transferring Version coding information from one EGS to another. I plugged in my original module, told DAS to transfer coding data and bingo! The Ebay module started working just like my original one.

3. In order to determine which gear failed I had to drive with DAS connected and in EGS live data mode. I was able to see speed sensor readings and all the shifts. In my case the problem occurred when shifting from 3rd to 4th. DAS showed Actual/Target gear as 3/4 and it would never become 4/4 eventually resulting in fault.

4. I was not able to bench test transmission speed sensors other than checking their resistance. I tried powering them up and then swiping some metal object right over them but that did not result in any output. I was able to verify they worked correctly while driving with DAS in EGS live data mode.

5. I was able to bench test solenoids for their operation by hooking them up to 12V power supply. I also tested them with a simple manual vacuum pump to make sure they really opened up when the power was connected.

6. This one is obvious but nevertheless I made this mistake. When installing solenoids with o-rings make sure they go into their seats with some good resistance. If they slip easily you have to install new o-rings. Or even better - replace the o-rings for a piece of mind if they are not relatively new. Mine seemed to fit OK when I was replacing the conductor plate, but once I determined I had a 3-4 shift problem and took the valve body off again I discovered 3-4 shift solenoid having almost no resistance when going into its seat.

I actually disassembled and cleaned my valve body but I found no problems there. All springs were fine, there was no excessive wear in any bores. The valves looked like new. I also installed Sonnax Overlap Control Valve Sleeve kit because I thought Sonnax design was better than the original MB one.

And finally if you are planning on working on these (W140 and later) cars yourself you must have Star Diagnostic System (which contains DAS program). Without it you cannot even clear the codes so you will be stuck in the limp home mode...
 

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Discussion Starter #16
Seth,
When I took the valve body off second time I knew I was dealing with 3-4 shift problem. The very first thing I checked was the 3-4 shift solenoid which after removing the clamp (or holder if you will) rocked in it's seat quite a bit. It came out of that seat with no resistance and went back in without any resistance again. I knew right away I had a problem. Other solenoids had some resistance and this one had none.

Oh, and you are right, the other way to get these o-rings is to buy new solenoids. I did consider that option but decided to try a cheaper route. The only risk was having to remove valve body one more time :)
 

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The transmission issue is finally fixed! It turned out to be old o-rings on the 3-4 shift solenoid. Apparently when I replaced conductor plate the old o-rings got disturbed and for that one solenoid it no longer provided sufficient seal. Thus when EGS tried to shift to 4th gear the transmission would not shift and the EGS would report 055 and 151 fault codes (Gear comparison negative. Target gear not achieved) and would go into limp home mode.

Since MB does not sell these o-rings and I did not want to buy $90 transmission seal kit from my local Transtar store I ended up getting a few different size metric Buna-N 90 o-rings from theoringstore.com. The ones that worked were 2x5mm and 2x12mm for shift solenoids and 2x12mm for TCC solenoid. Actually the same o-ring also works well for motor oil dipstick (mine was very hard and no longer sealed). So ordering 5 of those was a good idea.
Thank you for coming back and sharing what happened..

Martin
 

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Excellent info petcern, thanks.

Here in Aust. to get O-rings look up CBC or BSC in your nearest industrial area. They sell O-rings, bearing & various other parts for industrial parts.
Walk in and work with a sales guy to get the O-ring sizes you want. Get hold of Viton O-rings if you can, although they don't come in as many sizes as Buna-N
 

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This should be a sticky. There's also a spring that can fail in the valve body that can be replaced with ingenuity; not the whole valve body like MB would try to sell you. These 2 threads belong together.

I just changed my fluid and conductor place; shifting much better. Smooth. Not sure of the condition of the seals and spring.
 
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