Advice on Lockup Feel solenoid for 4L65e

[mcneil]

Looking for what I should do with the Lockup feel solenoid on my 4L65e. I would like to get up and running as simply as possible, so I'm wondering if I can leave the LUF solenoid disconnected.

The transmission connector has Pin U connected to the Lock up feel with 11 ohms resistance across pins E & U.

I found the post here and found it helpful, but do I need to use the LUF solenoid at all?

viewtopic.php?f=4&t=17

[Philip Lochner]

I'm learning that some 4L60e's are more equal than others....

Mine has got "PWM" written on it which I believe means that it also has the lock-up feel solenoid.


This was not by choice. Being unaware of this issue I simply ordered "a 4L60e" not knowing that some have this solenoid and others not. It seems to me it would have been preferable to have transmission without it.

So, I'm also interested to hear what to do with it. The Mshift documentation does not mention much about this solenoid and neither the firmware. I did find the following (but still does not help a lot):
http://www.msgpio.com/manuals/mshift/control.html
http://www.msgpio.com/manuals/mshift/4L80E/4L80e.html

[Philip Lochner]

I found this info. Must figure out now how to implement this in MShift. Some help would my much appreciated.

[Bernard Fife]

Philip,

I know very little about the LUF solenoid and how it ought to be controlled. Everything I have found is already in the manual. The info you have posted, is that for the TCC solenoid or the LUF solenoid (is that what they are calling the TCC PWM valve)? It looks like it ramps from 25% to 50% PWM, then holds for a similar period, then goes to 100%. The code doesn't do this right now, but could be made to mimic this behavior. We would need to have a running, installed transmission and a willing tester before any code can be tested, of course.

Lance.

[Bernard Fife]

Just to flesh this out a little more, what I propose is to add two new parameters to the LUF control:
- apply time and
- apply value

The current code allows the PWM% to vary from a user set value (via an interpolated value based on two points) to the fully locked value (normally 100%) over a period the user specifies ("PWM Taper Time").

Added to this, the apply value would set an fixed limit on the PWM% after the taper time, and would hold this value until the user set 'apply time' has elapsed.

LUF_params2.gif (17.02 KiB) Viewed 16994 times

I think this is what would most closely match what I have read in the documents.

Lance.

[Philip Lochner]

The info you have posted, is that for the TCC solenoid or the LUF solenoid (is that what they are calling the TCC PWM valve)? It looks like it ramps from 25% to 50% PWM, then holds for a similar period, then goes to 100%. The code doesn't do this right now, but could be made to mimic this behavior. We would need to have a running, installed transmission and a willing tester before any code can be tested, of course.

Yes, they call the TCC LUF solenoid "TCC PWM" and the on/of TCC solenoid exactly that - "TCC Solenoid".

My MShift kit is being cleared from customs as I write this, so I hope to have the hardware soon. Then once I have it more or less running , which I intend to be within the next two weeks, I would be most willing to test, log and report until you are satisfied that we have a good solution.

I am hoping to be able to utilise the TCC even in 1st on my Jensen. I had a '99 4.6 Range Rover "P38" once which used TCC in every gear which made the ZF 4HP24 feel as if it was an 8-speed, when in fact it was just the TCC locking in each gear. This was only noticeable on larger throttle openings.

[Philip Lochner]

I think this is what would most closely match what I have read in the documents.

Lance.

I understand that PWM and ramping it up is currently applied to the "TCC solenoid" output. This was done to achieve a smooth TCC lockup IN THE ABSENCE of the LUF.

Now with a LUF, the "TCC solenoid" will simply get a hard on/off (ie no PWM) and PWM will only be applied to the LUF output as per your proposed regime? If so, it looks good to me.