# 2011 335d transmission slippage when cold



## Nadir Point (Dec 6, 2013)

DnA Diesel said:


> What codes should we be looking for to indicate the fault?.


I'm afraid you will have to rely on your aerospace industry experience, automotive expert buddies or Hooper for answers. I don't have the time or inclination to trifle with you, but will attempt to educate you one more time, despite such an embarrassingly arrogant show of non-knowledge.

Try doing some more research. Maybe you can point to the actual information within a document, answering the very simple question at hand, rather than attempting to flaunt your clear lack of understanding of such material by posting links to it? 

Let me refresh your memory - topic at hand: Why is my transmission slipping?

Hints: The answer is in the document you posted. I answered the question already in laymen's terms. It has something to do with a bit called called a pressure regulating solenoid related to SHIFTING and torque converter clutch engagement, not LOCKUP.

OBTW, the ELECTRONIC transmission you seem to know so much about is a fundamentally hydraulically motivated device, whose pressure-sensitive controls certainly are affected by fluid temperature in terms of cold viscosity. Electronic controls modulate hydraulics to produce SHIFTS. Line pressure is also is responsible for torque converter clutch engagement, or lack thereof, in this case, i.e. SLIPPAGE.

Lockup, no so much. Yeah that's all electronic. Thanks for that tidbit, Hooper, you are correct, sir.


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## Hoooper (Jun 17, 2013)

Can you stop beating around the bush and let us know what you think is slipping and why you seem to think the computer cannot delay cold lockup by a few mph?


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## robster10 (Oct 8, 2012)

Hoooper said:


> Nadir if the gear was slipping like you are suggesting, you would lose that gear in a matter of miles, not tens or hundreds of thousands of miles. Clutch material is not capable of withstanding significant amounts of slip like what you are suggesting. The clutches toast in very short time.


:thumbup:


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## DnA Diesel (Jul 31, 2010)

Nadir Point said:


> I'm afraid you will have to rely on your aerospace industry experience, automotive expert buddies or Hooper for answers. I don't have the time or inclination to trifle with you, but will attempt to educate you one more time, despite such an embarrassingly arrogant show of non-knowledge.
> 
> Try doing some more research. Maybe you can point to the actual information within a document, answering the very simple question at hand, rather than attempting to flaunt your clear lack of understanding of such material by posting links to it?
> 
> ...


Right there you lose everyone. We understand torque converter clutch engagement TO BE "lock-up."

When the TCC is NOT engaged is when slippage between the impeller and the turbine occurs, causing the effect of increased engine rotation relative to the road speed.

As several of us have stated, the ZF 6HP26 electronically controls the hydromechanical engagement of the TCC, dependant on, amongst other parameters, the temperature of the transmission fluid.

What part of "You will find p.13 refers to the relationship between the TCM itself and the fluid temperature sensor..." was I not sufficiently clear about?

Perhaps I should be even clearer about what information p.13 contains and how it relates to the topic at hand:



> *GA6HP26Z:* [model of the 6HP used in late-model E38s] the [temperature] sensor is located in the mechatronics module in the transmission.
> 
> "The transmission oil temperature information is used to:
> 
> ...


The second bullet point is exactly what many of us are referring to, it certainly is the point that I have been attempting to make for the last several posts.

In cold weather, the TCM will inhibit TCC engagement (i.e. delay lock-up) until a set temperature is reached. I don't have that mapped temperature on hand, but anyone running a diagnostic like Torq or BMWhat would be able to determine at what temperature for the transmission fluid will the TCC be enabled.

There is no intent to be arrogant, although I suppose that my intent not to be, notwithstanding, is something you do not accept. I suppose that is what it is. Until then, I would be very interested to know how a torque converter clutch can be engaged and, if working correctly, the TC is not locked up?

Regards

D.


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## Nadir Point (Dec 6, 2013)

So you believe TCC refers to lockup? Is that correct?

And the TQ converter clutches cannot withstand slipping? Correct?

Is that the basis for your analysis? :dunno:

Just want to be clear.


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## Flyingman (Sep 13, 2009)

Nadir, DNA,

Please try and refrain from being so snarky. It's really not necessary to get your points across to each other. It's just a technical discussion. Thanks!

From what I am understanding the point is that under colder conditions the controller allows the Tranny to "slip" more until such time the oil temp has reached a pre determined set point. That slippage is not physical clutches (as in the old days of manual transmissions), but is hydrualic which basically causes windage or losses which equates to heat, allowing the hydrualic fluid to warm up quicker.

Sorry to butt in.


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## Hoooper (Jun 17, 2013)

Nadir Point said:


> So you believe TCC refers to lockup? Is that correct?
> 
> And the TQ converter clutches cannot withstand slipping? Correct?
> 
> ...


TCC = torque converter clutch. Torque converter clutch engagement is lockup. I have a feeling you are referring to lockup as the stall RPM which is most certainly NOT lockup and there is still significant slip beyond that RPM. I wouldnt blame you though, there are a handful of people who inaccurately describe stall speed as lockup online and in shops. This may have been a more legitimate use of the term before the torque converter clutch was invented but its not the proper use of the term "torque converter lockup" now. If stall speed was lockup, I wouldnt need the TCC to be working on my 5.3 truck, where cruising speed is 2500 RPM and torque converter stall is 1600 RPM. Yet, at 2500 RPM with TCC not enabled, converter slip ranges between 100 and 400 RPM. TCC clutch performance code will be triggered at a slip over 50 RPM for a period of time and with TCC enabled my converter slip at the same 2500 RPM condition will range from 0 to about 20 RPM.

Nobody said anything about torque converter clutch slipping.

I think you need to reread the OP. He noted two things. 1) The engine revs up before shifting when cold. 2) The engine will rev in gear when cold.

The reasons for those are: 1) Shifts are delayed when cold. 2) Torque converter clutch engagement is delayed when cold.


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## Nadir Point (Dec 6, 2013)

No, that is absolutely incorrect. Torque converters have clutches that work very similarly to the way conventional clutches do in manual transmissions. They are "wet" clutches.

OBTW, DnA - welcome to my ignore list. I'm sure you'll be happy there with Hooper, et al. 

And another thing: The torque converter's clutch has NOTHING to do with lockup, except the force with which it is applied.

Arrogant ignorance begets snark.


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## Hoooper (Jun 17, 2013)

Nadir Point said:


> No, that is absolutely incorrect. Torque converters have clutches that work very similarly to the way conventional clutches do in manual transmissions. They are "wet" clutches.


where did I say anything about how the torque converter clutch works or whether its wet or dry?



Nadir Point said:


> And another thing: The torque converter's clutch has NOTHING to do with lockup, except the force with which it is applied.


what the heck is that even supposed to mean? I could draw, describe, or do a play on how the torque converter clutch works, and I have no idea what you are trying to say here. Please do a little google searching on what converter lockup is, how it works, and then come back and try to explain what youre trying to say. Here is some beginner info on torque converters, their clutches, and what lockup means in 2015.

http://www.bankspower.com/techarticles/show/9-understanding-torque-converters

http://www.bankspower.com/techarticles/show/9-understanding-torque-converters

http://en.wikipedia.org/wiki/Torque_converter


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## robster10 (Oct 8, 2012)

Entertaining! ***55357;***56860;


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## Hoooper (Jun 17, 2013)

robster10 said:


> Entertaining! ***55357;***56860;


That's a language I definitely don't speak!


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## robster10 (Oct 8, 2012)

Hoooper said:


> That's a language I definitely don't speak!


Sorry Hoooper! Should have been Entertaining :rofl: Don't know why those codes showed up? Maybe this topic on slippage, converter lock-up threw a trouble code!


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## Hoooper (Jun 17, 2013)

Causing the server to slip!


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