ECU tune Transmission control unit? - Page 14

Huskymaniac · #**196** 08-20-2011, 09:53 AM

Quote:

Originally Posted by longassname

Correct, I can and have done MQ TCUs. I do not know if you can replace an MY with an MQ. I've been told the cars with MY TCUs have more wires in the plugs but only by one source with no independent verification. I do know the MY TCU is much smaller and mounts differently so even if were electrically interchangeable it probably wouldn't be easy to do.

So to make it very clear: If you have a 96 with an MQ TCU I can do it.

After my kids are done breaking boards at a demo, I will look for my TCU.

I recall at one point you had captured oscilloscope waveforms of the solenoid A signals. Can you post them again or point me to the original posting. I couldn't find it and I am interested in clarifying my understanding of how it all works.

If I recall correctly, opening up the valve body and the TCU upgrade speed up the shifts, in addition to increasing the hold pressure at low throttle. How/Why does that work? Neither upgrade changes the timing of the signals to the transmission, or do they? In my mind I envision a signal that throttles back the engine followed closely by a signal that decreases the clutch pressure followed closely by the signal to change the gear. Then, after some set period of time the clutch is reapplied followed closely by the engine being throttled back up again in accordance with whatever the TPS reading is. If the timing/duration of these events are set, how does the shift speed up? Is the start of the gear change and the throttling back up of the engine done after specific durations of time or is there feedback of the line pressure that is used to trigger those events? If that were the case, I could see how, for example, better flow through the valve body would help since the line pressure should ramp up and down more quickly.

longassname · #**197** 08-20-2011, 10:15 AM

Nope,

I do have o-scope readings of the solenoid a signals and they probably are on my webserver somewhere because that's how I made them available to someone who needed them for diagnostic purposes but I am not posting them for discussion.

There are a couple forum members who have bitterly disputed the control of solenoid A for years and have become so committed to their fight that they hold grudges against anyone who posts anything contrary to what they have said and launch prolonged campaigns of revenge. I don't want to be part of that or see it brought up again.

Huskymaniac · #**198** 08-20-2011, 12:32 PM

Quote:

Originally Posted by longassname

Nope,

I do have o-scope readings of the solenoid a signals and they probably are on my webserver somewhere because that's how I made them available to someone who needed them for diagnostic purposes but I am not posting them for discussion.

There are a couple forum members who have bitterly disputed the control of solenoid A for years and have become so committed to their fight that they hold grudges against anyone who posts anything contrary to what they have said and launch prolonged campaigns of revenge. I don't want to be part of that or see it brought up again.

Well, crap, I have an MY, not an MQ.

On the waveforms, can you PM me a link to them? I understand why you don't want to post them. And you comment on my question about why/how the shift time is improved with the valvebody and the TC upgrade? You can put that in a PM too if you don't want it to trigger a conversation here. Thanks. I never thought having a newer car would be such a frustration........

Tapani · #**199** 09-04-2011, 09:31 PM

Good morning,

Swithcing from the Q&A shift map thread - my suggestion for the 4.444 down shift thresholds are the scaled down stock vehicle speed values. That way the engine lands at app 4800 rpm max when down shifting, a bit less when shifting all the way down to first. Some might have a higher number in mind :-).

Please note, that the threasholds are much higher in POWER mode - maybe this feature could be utilized here too?

Kind regards,

Tapani

Sean486 · #**200** 09-06-2011, 06:49 AM

Michael, give me a few more details of what you would like tested. What I did before was floor it to see the shift points, then floored it a few more times when it was in 4rth gear.

Do you want me to floor it while driving at different speeds to see the down shift, is that the idea?

longassname · #**201** 09-06-2011, 07:22 AM

Hey Sean,

Don't worry about it for now. I started to work on it this morning and looking at the shift maps I see the US downshift maps do have a speed threshold above which they won't downshift. The absence of the threshold in Phil's plots was just an error in the plots or in the function he wrote to generate the plot data. Looking at the 3 to 2 downshift map changing the threshold by the change in gear ratio will adjust the threshold to only downshift at speeds that will result in an rpm of 4800 or less after the shift (not counting any flare during the shift or differential in the torque converter). That sounds reasonable to me.

If you want to test the value I'd be using for the 3 to 2 downshift threshold take your car up to 50 to 51 mph in 3rd and floor it to make it downshift into 2nd. This would be the highest speed flooring it would result in a downshift after the threshold is adjusted.

longassname · #**202** 09-06-2011, 11:27 AM

Ok, to illustrate the difference in the downshift maps when editing the speed threshold above which downshifts won't occur I did before and after graphs. The 2 to 1 shift is the ECUtune map and didn't require any alteration. Speed is in kmh. 127 is 100% throttle. The changes are onlly to the values at and above 88% throttle.

Tapani · #**203** 09-06-2011, 09:41 PM

The thresholds look good to me ! Will you do these changes in all maps or just DRIVE?

Tapani

PS With the ECUtune valve body there's NO flaring - the improvement in both high load upshifts and downshifts is awesome. I have to check my brake band adjustment, I still get a "braking effect" whith closed throttle up shift 2-3 when the tranny is cold. Going down hill, I mean. The high clutch applies before the brake band fully releases? The valve body swap had no effect in this.

longassname · #**204** 09-07-2011, 06:31 AM

I manually made the changes to the Drive maps for comparison's sake. Now I'm adding functionality to the ECUtuner software to make the changes to the TCU firmware. I've already received feedback from 4.44 driver's that they do not believe they will want their entire shift maps scaled by the gear ratio like Phil did for Ron; they want to stay in gear longer so it looks like my idea to modify only the thresholds will be the winner. I'm going to write routines to do both. Yesterday I got as far as writing and debugging the code for defining and looking up the shift maps based on the # of modes and the address of the pointer to the first shift map. Today looks busy but hopefully tomorrow I will be able to get back at it and write the functions to make the changes to the shift maps.

Sean486 · #**205** 09-07-2011, 07:14 AM

So we will need get the ecutuner plus cable for this change?

longassname · #**206** 09-07-2011, 08:59 AM

Nope, I'm going to use the ECUtuner software to make the changes to the TCU firmware I will then send you a ROM with the new firmware to install into your already socketed TCU. You will remove the old ROM from the socket and install the new ROM.

Quote:

Originally Posted by Sean486

So we will need get the ecutuner plus cable for this change?

Sean486 · #**207** 09-07-2011, 09:00 AM

Quote:

Originally Posted by longassname

Nope, I'm going to use the ECUtuner software to make the changes to the TCU firmware I will then send you a ROM with the new firmware to install into your already socketed TCU. You will remove the old ROM from the socket and install the new ROM.

Awesome, thanks.

longassname · #**208** 09-30-2011, 07:33 PM

I've made a revision to the solenoid a maps. Completely flatlining the 3rd and 4th gear solenoid a maps at max pressure had prevented engine braking if the shift lever was put into 3. While everyone was willing to give up engine braking for the benefit of beefening up the torque carrying capacity of the high clutch it wasn't necessary. I've now modified the maps to have low line pressure below 5% throttle so that engine braking is uneffected and jump to max line pressure as soon as the throttle is pressed. This change has now been tested and proven a winner all around. Here's the new map used for 3rd and 4th.

Tapani · #**209** 10-01-2011, 12:28 AM

Great !

Tapani

Huskymaniac · #**210** 10-01-2011, 03:40 PM

Quote:

Originally Posted by longassname

I've made a revision to the solenoid a maps. Completely flatlining the 3rd and 4th gear solenoid a maps at max pressure had prevented engine braking if the shift lever was put into 3. While everyone was willing to give up engine braking for the benefit of beefening up the torque carrying capacity of the high clutch it wasn't necessary. I've now modified the maps to have low line pressure below 5% throttle so that engine braking is uneffected and jump to max line pressure as soon as the throttle is pressed. This change has now been tested and proven a winner all around. Here's the new map used for 3rd and 4th.

Can you give a simple answer as to why high line pressure prohibits engine braking. I am still trying to learn how these trannys tick. I would think high line pressure would be important during engine braking and especially if someone manually shifts down from D to 3 to avoid slipping.