When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
About a year ago, with about 108K on my 2010 e350 2wd with a 722.9, I started experiencing harsh transmission engagements along with shutter/vibration. Changing the fluid in the trans(not the torque converter) fixed the issue. Here is the thread
A few days ago at around 125K I started experiencing surging(200-300rpm) while maintaining speed. I did not see any codes albeit 2 weeks ago when the temps dropped in South Florida.
That same day 2 weeks ago I received the codes below. I cleared them and they did not return.
0745 mixture (cylinder bank 1) is too lean
2091 The mixture (cylinder bank1) is too lean at idle speed
0749 the mixture (cylinder bank 2) is too lean
2095 The mixture (cylinder bank 2) at idle is too lean.
Fast forward to the present day, after the surge issue came back, I reset the adaptation values. Until this point, I had no related ECM or TCM codes. Well, it made things worse. When I got home I had TCM codes:
P0894 – the transmission is slipping
P0735 – Gear 5 is implausible or the transmission is slipping
After a few days and about 100 miles of driving I also have :
P0741 – Actuation of the torque converter lockup clutch is not possible
P2783 – The friction power of the torque converter lockup clutch is too high
P0218 – The oil temperature of the transmission is too high
Using my autel scanner I looked at the TCM live data. The status of the torque converter lockup clutch is either “OPENED” or “SLIPPING”
Additionally, the “lean cylinder mixture” codes are back. This time I have them for both banks (1 & 2)
My thoughts: Can the cylinder running leans be related or irrelevant to the potential transmission issue...
Do ya’ll think I have have a bad torque converter? Do you think it might be worth changing the fluid again or fast forward to a new TC? Thanks in advance.
About a year ago, with about 108K on my 2010 e350 2wd with a 722.9, I started experiencing harsh transmission engagements along with shutter/vibration. Changing the fluid in the trans(not the torque converter) fixed the issue. Here is the thread
A few days ago at around 125K I started experiencing surging(200-300rpm) while maintaining speed. I did not see any codes albeit 2 weeks ago when the temps dropped in South Florida.
That same day 2 weeks ago I received the codes below. I cleared them and they did not return.
0745 mixture (cylinder bank 1) is too lean
2091 The mixture (cylinder bank1) is too lean at idle speed
0749 the mixture (cylinder bank 2) is too lean
2095 The mixture (cylinder bank 2) at idle is too lean.
Fast forward to the present day, after the surge issue came back, I reset the adaptation values. Until this point, I had no related ECM or TCM codes. Well, it made things worse. When I got home I had TCM codes:
P0894 – the transmission is slipping
P0735 – Gear 5 is implausible or the transmission is slipping
After a few days and about 100 miles of driving I also have :
P0741 – Actuation of the torque converter lockup clutch is not possible
P2783 – The friction power of the torque converter lockup clutch is too high
P0218 – The oil temperature of the transmission is too high
Using my autel scanner I looked at the TCM live data. The status of the torque converter lockup clutch is either “OPENED” or “SLIPPING”
Additionally, the “lean cylinder mixture” codes are back. This time I have them for both banks (1 & 2)
My thoughts: Can the cylinder running leans be related or irrelevant to the potential transmission issue...
Do ya’ll think I have have a bad torque converter? Do you think it might be worth changing the fluid again or fast forward to a new TC? Thanks in advance.
R realize you really have a small collection of errors that went from bad to worse.
I would take your lean issue independently. Right now any trany shop is joing to sign you up for a rebuilt unit. So get yout engine stale then deal with any remaining tranny issue .
Your engine lean codes sound related to ignition or fuel.
My thoughts exactly regarding the leans codes; independent of the tranny issue. Simply the causation without correlation effect. I changed my plugs about 20K ago
Plutoe, it will cost me several hundred $$ to change the fluid, only to perhaps need to change it again. I changed it not that long ago.
Cali, when you say a rebuild unit, do you mean the TC or an entire tranny?
My thoughts exactly regarding the leans codes; independent of the tranny issue. Simply the causation without correlation effect. I changed my plugs about 20K ago
Plutoe, it will cost me several hundred $$ to change the fluid, only to perhaps need to change it again. I changed it not that long ago.
Cali, when you say a rebuild unit, do you mean the TC or an entire tranny?
First of all: get the engine running right.
Your ignition is already ok
Check fuel pressure
Don't bother with tranny replacement right now (besides mandatory ATF). Get it back to how it was earlier.
It's performance is based on the engine and timely CAN-Bus controls.
To answer your question: whole unit (gearbox, Clutches, TC, Valve body with TCU) . Nothing cheap about its parts + labor.
++++ Tranny Faults... ATF TOO HOT!
Be careful about cooking all your seals getting tranny too hot. It leads to low pressure and slippage, clutch stacks destruction.
Last edited by CaliBenzDriver; Dec 30, 2024 at 01:49 PM.
Roger that CBD. I checked the fuel pressure. It was ~60psi I forgot to include a few other codes which I thought were irrelevant, but I will explain why.
U103888 – Stored – Communication with the diagnostic CAN bus has a malfunction. Bus OFF
I overlooked this one.^
0522 Active and Store – The charge movement flap(cylinder bank 1 has a malfunction
I purchased a manifold from 1A auto and changed the entire manifold in February 2023. The code persisted so I thought maybe it’s a faulty connector – so I ignored it.
0155 Active and Store – The coolant thermostat has an electrical fault or open circuit
I accidentally broke the thermostat housing connector.
0407 Stored – Shutoff valve ‘Heating system” has an electrical fault or open circuit
Perhaps this is related to the broken thermostat housing. Perhaps irrelevant to my issues.
--
Yesterday I ordered a transmission service kit from FCP euro. It's should be delivered on Jan. 6. Are you implying I should change the fluid even though I changed it less than 20K miles ago?
Roger that Cali.
I checked the fuel pressure. It was ~60psi I forgot to include a few other codes which I thought were irrelevant, but I will explain why.
>> I see.
U103888 – Stored – Communication with the diagnostic CAN bus has a malfunction. Bus OFF
I overlooked this one.^
>> yes, this is scanner disconnect issue. ok
0522 Active and Store – The charge movement flap(cylinder bank 1 has a malfunction
I purchased a manifold from 1A auto and changed the entire manifold in February 2023. The code persisted so I thought maybe it’s a faulty connector – so I ignored it.
>> Fix issues as they come👍
0155 Active and Store – The coolant thermostat has an electrical fault or open circuit
I accidentally broke the thermostat housing connector.
>> Yes, without working Tstat control by ECU it's max heat opening only.
0407 Stored – Shutoff valve ‘Heating system” has an electrical fault or open circuit
Perhaps this is related to the broken thermostat housing. Perhaps irrelevant to my issues.
--
Yesterday I ordered a transmission service kit from FCP euro. It's should be delivered on Jan. 6.
Are you implying I should change the fluid even though I changed it less than 20K miles ago?
>> 20kMi ATF is good enough, changing it won't help your issue.
>>> READ my answers within your text above
Your top issue is what's causing your LEAN faults.
unlikely fuel
unlikely ignition
...
unlikely intake new flap?
--> check/replace vacuum pump 1-way-valve.
Last edited by CaliBenzDriver; Dec 30, 2024 at 04:28 PM.
The intake manifold has a "lifetime warranty". Maybe I can replace the entire part again. However, it looks like I have bigger fish to fry.
How should I approach fixing the scanner disconnect issue?
I purchased the ATF because I figured it would be necessary either way. Whether I give it a good ole college try or save it for the TC/tranny work.
Honing in on the torque converter problem, I have an indy mechanic near my house who I trust more than others. I also have a few reputable transmission shops in the area. I am technical enough to change the TC but I don't have the time. Who do guys think should bid on the job? The Indy or transmission shop? My intuition says the indy mechanic. Mercedes Mike - if you are in Pompano Beach.
The intake manifold has a "lifetime warranty". Maybe I can replace the entire part again. However, it looks like I have bigger fish to fry.
How should I approach fixing the scanner disconnect issue?
I purchased the ATF because I figured it would be necessary either way. Whether I give it a good ole college try or save it for the TC/tranny work.
Honing in on the torque converter problem, I have an indy mechanic near my house who I trust more than others. I also have a few reputable transmission shops in the area. I am technical enough to change the TC but I don't have the time. Who do guys think should bid on the job? The Indy or transmission shop? My intuition says the indy mechanic. Mercedes Mike - if you are in Pompano Beach.
I vote for "a Mercedes shop" who can help you sort Mercedes issues.
A tranny shop sales tranny jobs. They are not in business of tuning conductor plates for peanuts when big jobs are stacking up.
As far I understand... you had no tranny issue before you put on reset on the TCU conductor Solenoids.
Besides what ever issues were there are still out standing.
Your fuel pressure reads well, yet you have a lean with newish sparkplugs and no coils misfire.
You had intake issues... perhaps causing your lean due to MAF or intake unmetered leak.
Right on, Cali. I'm waiting to hear back from my indy merc tech
I had no dire tranny issues. Just a surge that was happening(without the shutter) like the time I changed my ATF fluid a year ago.
I'm tied up today with NYE's. I took a quick look under the hood and noticed the intake tubes were a bit loose. I'll further inspect the MAF later or tomorrow.
Theres like 9L in the system, about 6L comes out through the conventional pan, buy extra ATF to rinse the transmission by overfilling it and letting the excess come out. The old fluid has contaminated the new stuff. When transmission fluid gets hot it loses its ability to resist foaming and thickening.
As for the lean codes... I think you have a vacuum leak if all cylinders aren't having a great time.. could you tell me how the intake is sitting on your MAF right now? is the donut in good condition?
Well noted regarding the ATF. Although, I am standing by for now. I dropped off the merc at my indy shop. The surging problem has disappeared over the past few days. Yet, the hard downshift and at times upshifts are still there. The transmission seems confused when I accelerate enough to cause a downshift. There is loss of power for a moment while the transmission things about what gear select. Additionally, P2783 – The friction power of the torque converter lockup clutch is too high -- is still 'active and stored' while the others codes are just 'Stored'.
I will get more details regarding the intake the next time I'm near the car.
Last edited by tobe1424; Jan 10, 2025 at 02:50 PM.
Well noted regarding the ATF. Although, I am standing by for now. I dropped off the merc at my indy shop. The surging problem has disappeared over the past few days. Yet, the hard downshift and at times upshifts are still there. The transmission seems confused when I accelerate enough to cause a downshift. There is loss of power for a moment while the transmission things about what gear select. Additionally, P2783 – The friction power of the torque converter lockup clutch is too high -- is still 'active and stored' while the others codes are just 'Stored'.
I will get more details regarding the intake the next time I'm near the car.
It may well be that your 15yrs old TC Clutch is warped blue/worned out... so what, it's a secondary clutch.
You can drive tranny as-is in S-mode to prevent locking that clutch !! Of course newly rebuilt everything would be best but cost is upside down.
I got the car back from my indie tech. I got the same feedback I did when I showed him the codes on my scanner prior to him looking at the car. It sounds like he read off the scanner. He said his approach would be to replace the torque converter and gears 5 and 6.
I cleared the codes today. I am going to drive the car today to see what codes reappear.
I did see a new code today. Stored - P0606 - Component 'CP48 (Fully integrated transmission control control unit)' is faulty.
Am I crazy for starting to believe this might be an issue with the TCU?
I got the car back from my indie tech. I got the same feedback I did when I showed him the codes on my scanner prior to him looking at the car. It sounds like he read off the scanner. He said his approach would be to replace the torque converter and gears 5 and 6.
I cleared the codes today. I am going to drive the car today to see what codes reappear.
I did see a new code today. Stored - P0606 - Component 'CP48 (Fully integrated transmission control control unit)' is faulty.
Am I crazy for starting to believe this might be an issue with the TCU?
Thanks
RPC
...as you can see, the faults are NOT consistent.
So yes your TCU is truly having some kind of hard time.
This doesn't mean you best ignore troubleshooting and buy a rebuild job.
What's causing crazy TCU is everybody's best guest. Lots of items are eligible to cause tranny chaos including rodents love for harness. Start with a comprehensive chassis scan.
Meaning don't rush to the top most expensive item to realize it's a 5¢ fuse only after you've spend a stack.
Thanks for your response.
A few days after my last post the car went into limp mode. At first it simply revved in place. After switching to Park and Drive a few times it engaged and I drove home in what seemed 2nd or 3rd gear(almost sure it was 2nd). Check engine lights came on.
No new codes on the engine, but the tranny codes returned in numbers.
Stored: P0894 - The transmission is slipping.
Stored: P0734 - Gear 4 is implausible or the transmission is slipping
Stored: P0733 - Gear 3 is implausible or the transmission is slipping
Stored: P0732 - Gear 2 is implausible or the transmission is slipping
Stored: P0735 - Gear 5 is implausible or the transmission is slipping
--
The car has been sitting for a few weeks. I turned it on for about 10 minutes; moved it around the drive way. I'm not sure what to do next.
My indie said to buy a used transmission and swap it out. Most scenarios I've come across seem to have different codes when it comes to TCU issues. Whether it be speed sensors or solenoids.
The wiring looks good. I don't have any critter problems. I know what you mean about not rushing to a conclusion, but I do need to take some sort of action :|
Unfortunately, if you take the car to Mercedes, they are almost certainly going to charge you for a diagnosis then suggest a new (rebuilt) transmission.
If you can find a low mileage junk yard transmission and TC, you should be good for the rest of the life of the vehicle. Probably $2500 + labor. Dunno what part of the world you're in...
You can try other easier things first, but the cost and time will quickly add up. You might get lucky or you might wish you had gone straight to the parts yard replacement.
After letting the car sit for almost a month, I decided to fire it up. I was handed a whole new set of problems. It was idling high and I have an entire new set of codes. Granted, maybe not related to the tranny issue and some were already present.
I drove the car around the block and by the time I got home it couldn't rev pass 1500rpm. I had to turn it off/on and that seems to have "fixed" that issue. I did some research on the high idle issue and came across thermostat related issues. Anyhoo..
I finally found a transmission with about 71K miles from a shop in California. If I swap out the transmission in my driveway, I assume the tcu will require to be reprogrammed with matching vin's amongst other calibrations. My Autel scanner can read but I am not sure it can write - I need to verify.
Anyone interested in a mechanics special car lol? I'll start the bid low. On a serious note, thank you all for the help and feedback.
Any advise on a DIY tranny swap? Or based on your last comment, do you think I should go back to the finding a power/ground issue and a CAN issue. If I recall correctly, I do have a CAN code. Let me find and I will post it shortly.
... with these faults you conclude you need to replace transmission! - How is that?
Your limp-mode is directly caused by crazy-throttle fault.
What's causing the ECU to misbehave (oil) needs serious troubleshooting.
At any rate don't spend your dime on the wrong parts: tranny is ok.
++++ I re-read prior conclusions above.
It's consistent.
Take this issue from the begining, front and center.
Clear faults
Charge up battery
drive
Scan
post results
Last edited by CaliBenzDriver; Mar 15, 2025 at 03:43 PM.
Thanks Cali, I forgot to mention that when I took the car around the block to fuel, my dash lit up with ESC and other flags. See cluster pic
Prior to not starting the car in a month, I had fully charged the battery. As a matter of fact, I have a charger/tender on most of my vehicles/boats. Not to mention the battery is less than a year old. It did get cold( by Florida standards - freezing) down here. Hence code 0228 - I assume
Moving forward, the battery is charged. I cleared the faults. I'll drive it around the block this week.
In any case, I posted the ESP and CGW scan results. Any pointers with respect to the CAN/CGW codes?
It would be a major breakthrough if we can pin point this to a module!
Thanks in advance.
Right when car went into limp mode. Overall scan view ECM codes Page 1 ECM codes Page 2 ESP codes CGW codes
it becomes evident the primary suspicion is a defective ECU. The top reasons being either: oil swamp or voltage chaos.
Not the tranny at all.
> How so...
Compare the ECU faults with orher module faults.
Then you get the idea of which is first.
Disruption is unlikely external to ECU.... ie. its internal disruption.
> Physically inspect ECU :
1 - Disconnect batteries
2- Remove both ECU Connectors: any oil??
oily swamp
Last edited by CaliBenzDriver; Mar 17, 2025 at 07:48 PM.
Cali, thank you for borrowing your time. I removed the ECU. I didn't see anything out of the norm. In my past when ECU's are having issues, the car generally doesn't even turn on. Anything else we can do pin point the issue to the ecu? Do the CGW errors mean anything?
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
