I been trying to figure out what's wrong with my s500. I got error codes for all electrical circuits a,b,c and torque converter clutch as well as a speed sensor code. I got a new conductor plate but it wasn't oem mercedes. So I swapped it out with a factory one. Still same codes. My I tried swapping out the tcu. It still did no good. I've tried everything and I'm all out of ideas. Hopefully someone on here can give me some good advice. Please

 

Check the transmission fluid level and condition 1st.If eveything came on all at once??Sounds like you did some work and might already have done that but if your basing your level on what came out and what you put in don’t.Check it with a stick.Might be a electrical issue if all warnings Came on at once.Water get into any of the main boxes like under back seat etc?Speed sensor usually has 0 effect on shifting but it’s the cheapest code you have.Abc you say is on?Or abs?Abc is rare suspension on a 500 but Is possible,

Anyways if the abc has fault or torque converter clutch your tranny can go in limp mode.If it’s ABS that has nothing to do with tranny. You might think it’s stuck in 1st but it’s 2nd gear. If you can go up to 40mph that’s 2nd gear.If it’s definitely 1st gear about 15-20mph then Its still possible to be limp mode but absolutely not safe to drive at all. Limp home mode is to protect the tranny when triggered by computer when it senses a issue.It will allow you to drive home much faster then 1st gear. Some people have had luck just doing the simple adaptive relearn process basically resetting your shift points.Im sure you know how to do that.But if that don’t work and a speed sensor neither,only way out of limp mode if infact your car is in it is through a reset via scanner and most likely it will trigger again immediately if it’s something major wrong with it.Most Of the time when issue is fixed it goes out of limp via ecu reset ‘disconnect battery’ you can try that now too.Some cars need a good obd tool to reset. Start at the small things,I’d check my oil level 1st every time with a tranny.Discconect battery reset the adaptive,And I’d think about how it was shifting and acting prior to this and was there any indications that tranny had some wear.

And as far as non oem parts, that’s just mostly not true.Maybe it’s true for the plate if it’s still a Made in Germany part,it will say on it. Mercedes ‘Germany’ doesn’t manufacture parts much anymore.You just learned that. oem plate made no difference.Bosch is now in China and so is most of our parts. About 80%.Bosch is 1 of the cheapest parts now made so if you have to buy a speed sensor or anything don’t hesitate to buy Aftermarket as long as it’s from Reputable places.

 

It's the shift solenoid a circuit electrical, solenoid b circuit electrical, solenoid c circuit electrical, and torque converter clutch solenoid electrical and p0715. Those are the codes I got. The battery I bought at a salvage yard only has 800 cca.... could that be a possible cause?

 

Yes of course.Ive seen shorted solenoids be the cause. But more often ive seen clogged solenoids and or sensors.’Debris from oil’. Very rare to kill a clean shift pack.You say you just had the tranny pan off to do some work?Surely you would have noticed excessive metal wear in the pan.You don’t say how measured your oil or if you did.I wouldn’t wana give a opinion until I knee atf fluid was checked with a stick.Your codes are pretty much saying all the shift solenoids are bad,usually it would be just a torque con,or a certain gear.

But still you say you just did work to the car what made you change the conductor plate?What was the car doing that made you replace that and was this issue there before the plate was swapped.Or were you having problems already before this work you did. I ask Cause IF NOT then YOU might have triggered the limp mode. It’s actually very easy to see if the car is in limp mode.are any warning lights flashing traction anything?are you stuck in 1st or 2nd gear right now?You need to Know that for sure.Limp mode would be a good thing as the tranny comp told the Cars comp there was a issue and it set it off. If the Trans was just worn out and toast you’d have lost reverse or forward completely or car won’t shift out of “1st” gear or will be slipping from D to R from 1st to 2nd etc. so limp mode is not the worst thing that can happen. You really need a scanner. My snapon tells me if the car is in limp mode. That’s why I said you need a decent scanner. Generic codes usually have you tossing parts at the car.

Disconnect the battery for a day if you can.Limp mode can sometimes be reset if you Caused it while working on the car or if it was something that spontaneously happened say tcm sensed short on atf fluid or a gear jump or something to that nature.What id be doing 1st,is make sure I’m in limp mode or not,that will guide me to next step.But you never responded to any of my regional questions. like i said how fast are you going before redlining 10-20mph ‘1st gear’ or are you Able to reach 30mph or more “2nd gear” Wich is most likely limp mode. Remove the battery if you can do it for 24hrs. Codes should reset from battery disconnect but reset them anyways before you start it immediately after you hook battery up. Even if it says no codes hit clear anyways. If it said no codes after battery reset and you start it and take note how long before codes come back on immediately or after you shift from Park to drive etc.

 

I havent pushed it to the red line yet. But I can go a little over 30 mph but the rpms reach 3500 . no issues with trans when I bouggt the car. I parked it for 3 months and it wouldn't start when I tried to crank it up after the long wait. The cause was the pre- fuse under passenger floor mat. Fixed it... But now it won't upshift. Obd2 scanner said speed turbine sensor, p0715 and p0763 , shift solenoid c electrical. I was told that meant to change conductor plate . so I did. Have again after that to a oem one( used). Havent used a dipstick for atf level yet... Got one ordered though. Pin connected is got a small leak. Ordered that to... But no damage to wires or tcu. Now I got the error codes mentioned... Is it possible that I'm just in limp mode and not reset it with a proper scanner? But in the meantime I'm going to do what you have suggested. Plz continue to help me through this. Thank you so much for the advice.

 

Yes absolutely,that would be the 1st thing I would check on any trans issue,the oil, codes or not.Especially you got a small leak.Hopefully your just so short on oil it’s not shifting.Definitely would send you into limp mode if you were.30mph at 3500 rpm sure sounds like 2nd gear and limp mode to me. Don’t drive it till you get the stick to measure.

In the mean time you say the car was parked I assume battery was dead now I’ve seen this happen ‘no shift’ after a dead battery.If your getting 13.5-14v when it’s running your ok on the battery.800cc is sufficient.

Really try the 24hr battery reset.Charge the battery during this 24hr.try this till the stick comes,I was gonna ask you to immediately try to drive it upon battery hookup codes cleared to see if it shifts But don’t.

1st,once battery is installed back,turn the key,leave it turned all the way 2 position don’t start it,if at all possible and your car is safe leave it turned like this overnight lights and electronics off obviously and battery charger on low,if not safe overnight do it early day,you’ve got key to lock the door if need be,but do it as as long as you can the point is if you can leave the key turned for a good 24hrs.We’re trying too reset computer and relearn few things.Sometimes it takes 20 minutes but I had dodge V8 similar tranny as yours and mine,had bad alternator I swapped it Car still wouldn’t charge after alt change and all the sudden wouldn’t shift gears and windows not working,all sorts of things,this car sat with dead battery for a while till Rey brought it to me.anyways We knew some cars need to relearn but 30min Max was usually it,this car after tryng 20-30 min increments with no luck I let it sit a whole day.Next morning Started it and bang,all was well.

ultimately you may end up with a bad torque converter or shift pack,or idk,
but the wise thing to do is start with throwing away pennies in the wishing well before quarters.

 

This is your choice. I was at the MB dealer this afternoon grabbing a tool to borrow,I asked 1 of the technicians I know he’s older dude goes by the book. Said change the speed sensor.The younger guy I asked said that won’t cause limp mode,anyways He also said if you turn the car on and off and back on and start and drive if that don’t clear limp mode then it wasn’t that sensor.What he’s saying is what I was telling you some issues if minor or spontaneous malfunction these can be cleared without a scanner. You can do this now or after doing what I told you about the battery and key procedure.
If you want the part number for the speed sensor I’ll get it for you. And have the place you go to,the zone or O’Reillys price match a shop online “not eBay” usually they’ll do it if it’s a well known name and you got a screen shot of the price. Peace out bro

MOE

 

I can't tell you how much I appreciate your time and effort. Yes I would love that parts number. But isn't the speed sensor on the conductor plate?? And i got the battery almost ready to go back in. Might b getting my hands on a dipstick today as well.... My fingers are crossed. Thank u

 

I can't tell you how much I appreciate your time and effort. Yes I would love that parts number. But isn't the speed sensor on the conductor plate?? And i got the battery almost ready to go back in. Might b getting my hands on a dipstick today as well.... My fingers are crossed. Thank u

 

And when you say on/off and on and start... Do you mean turn key in ignition on or crank all the way?

 

I personally never changed a speed sensor on these.I asked the the tech at the dealer,he said if it’s tossing a code swap it.Almost 90% of the time those guys are gonna tell you that you must change whatever it says.Thats why people pay so much at dealers and shops in general.Its called process of elimination.If you go to the dealer with 4 codes he’s gonna change all 4 parts and if it don’t work he’ll say well they were bad anyways.