7427 Rev limiter / 4L80E question

[dubwise]

Hey guys.. I have a few questions for you all regarding a 7427 swap w/a 4L80E. It is my understanding that I need to use $0E for the 4L80E. After that is where I get a bit foggy. So here is the back story 1st. I have a 92 454ss w/4L80E and 7060 PCM. The engine was formerly boosted and I had the EBL + 7060 piggy backed. Worked good for what it was. Since then I have swapped in a 540 BBC and gone carb/HEI distro and kept the 7060 for controlling the 4L80E.

Believe it or not I still have the EBL piggy backed with the 7060. The only thing the EBL brings to the table at the moment is WBO2 logging as unfortunately the EBL won't control a 4L60E or 4L80E. So, ideally I would like to ditch the EBL and have WBO2 logging via the 7060, but I read that isn't possible (or no one has figured it out yet). It is a major PITA to log trans functions w/the 7060 and WBO2 via EBL. I would like to aggregate the data streams which is where the 7427 comes in. I already found (on here) how to input a WBO2 in the 7427 so that is a good start. :-)


Here's a few questions I have regarding the 7427:


1) In my case, is it necessary to have a MEMCAL from a v8? My plan is to use an BURN2 (or Ostrich) along with the GP1. I picked up a 7427 w/the BJXK BCC. Hopefully I can use it...?

2) Regarding shift points / rev limiters for the 4L80E - what tables are these in the 7427? I found "Upshift RPM vs Shift" but it's zero'd out in the 0E bins (BHDF, BJDR, BMHK)??? I know in the 7060, to up the rev limiter it's in: "Kickdown up/down vs MPH" but I could not find the equivalent in the 7427.

3) Regarding the other 4L80E tables, like the TCC and line pressure, etc.. Are the bins floating around out there they have been "optimized"? I'm assuming BHDF, BJDR and BMHK are stock bins. Or am I on my own here trying to firm up the shifts and adjust TCC Lockup?

4) Is there a way to input a "Performance Mode" switch in the 7427? IIRC some of the older ECU's had this functionality where you could push a button and it would use a 2nd set of shift tables.

[gregs78cam]

Yes getting the '7427 to datalog WBO2, and run your 4L80E is relatively easy. To answer your questions:

1. You should have no problem using that '7427 to run the 4L80E. Just make sure it has a memcal with a chip with a $0E .bin burned onto it. I don't know if a V8 memcal is mandatory, as there are no fuel or timing outputs being used. But you should probably spend some time disabling any DTC's that you don't need. For datalogging and .bin editing be sure so use a $0E .xdf.

2. Doing the above should provide you with all the parameters you need to tweak the 4L80E to your liking. Most all of the trans stuff is near the bottom of the Constants, and Tables sections. Attached is the .xdf that 93V8S10 made long ago, and I added few features to, I use it for both of my TBI vehicles.

3. Anything out there that is "optimized", wont be optimized for your engine, gear ratio, or vehicle.

4. I don't believe that feature exists for the '7427.

[JeepsAndGuns]

To run a V8 engine I would reccomend a V8 memcal. There are differences in the limp home chips and the knock filter.
I just sold a V8 memcal to another member who was having issues with his system. He had a V6 memcal and a V8 engine.

[RobertISaar]

4. I don't believe that feature exists for the '7427.

i seem to remember seeing both code references and maybe even a diagram or two of a "manual, normal, perfomance" shift pattern switch.... i'll have to look around to be sure.

[billygraves]

........

[RobertISaar]

The rule with the 4L80-E is to keep the Force Motor, Valvebody, space plate, and TCM/PCM as a UNIT. If you want to know why I can respond.


Billy, that reminds of me of a question that i really don't know who else to ask and get a solid answer:

the PWM frequency of the pressure control solenoid/force motor sometimes changed depending on model year on certain transmissions, was there a general reason behind this? i want to say frequency always jumped upwards, never down.

i've been operating under the assumption that a new PCS/FM was specified/installed that could tolerate a higher frequency to keep the actual line pressure closer to target, rather than swinging above and below target pressure. i get the feeling that the inductance of the solenoid was what allowed this to be possible?

[dubwise]

Yes getting the '7427 to datalog WBO2, and run your 4L80E is relatively easy. To answer your questions:

1. You should have no problem using that '7427 to run the 4L80E. Just make sure it has a memcal with a chip with a $0E .bin burned onto it. I don't know if a V8 memcal is mandatory, as there are no fuel or timing outputs being used. But you should probably spend some time disabling any DTC's that you don't need. For datalogging and .bin editing be sure so use a $0E .xdf.

2. Doing the above should provide you with all the parameters you need to tweak the 4L80E to your liking. Most all of the trans stuff is near the bottom of the Constants, and Tables sections. Attached is the .xdf that 93V8S10 made long ago, and I added few features to, I use it for both of my TBI vehicles.

3. Anything out there that is "optimized", wont be optimized for your engine, gear ratio, or vehicle.

4. I don't believe that feature exists for the '7427.


Thanks!!



i seem to remember seeing both code references and maybe even a diagram or two of a "manual, normal, perfomance" shift pattern switch.... i'll have to look around to be sure.

That would be awesome if you could find this. Please let me know if you do.




I'll put in a couple.
In regards to the 4L80-E:
If you wish to have ONE PCM or controller, you can. Since you have a 92 with the older BOSCH force Motor controls, you can move to the Holley Force Motor Controls BUT YOU MUST replace the Valvebody assembly (with aux valvebody) and Force Motor.
The rule with the 4L80-E is to keep the Force Motor, Valvebody, space plate, and TCM/PCM as a UNIT. If you want to know why I can respond.
In order to move your 92 TRUCK to the 94-96PCM controls I would suggest you replace the valve body, spacer plate, VB gaskets, and I would replace the internal and splice in an external trans harness WITH the PCM. If this were mine with a 540 cu in, I would HIGHLY SUGGEST you seek out a BIG BLOCK Valvebody. These Vavlebodies had a higher GAIN in Line Pressure and is better selected to control the higher power. I would suggest you enlarge or remove the checkballs for the direct clutch circuit that is for 3rd gear. I would suggest you enlarge the 2nd gear FEED hole in the spacer plate. One CRITICAL ITEM is you BEGIN WITH A CALIBRATION or FILE or BIN that is set up for a 4L80-E and NOT try to make the calibration into one. In the definition file there are MISSING BITS AND CALIBRATIONS that are NOT defined in the XDF file. In plain there are things you cannot see or change in the cal you need to in most cases. How I know this is this was my job @ GM.


All good info. Thank you. Can you elaborate on why its a good idea to replace the force motor valvebody, space plate with this PCM swap? The 92 454ss came stock w/the 4L80E, so I would assume it already has the Big block valve body..?? The last thing I want to do is ruin the trans by doing this swap.




The XDF or Definitions has some trans calibrations. Wide OpenThrottle functions like this:
There are calibrations for WOT or it is called KICKDOWN HI and Lo. It works like this. Once the TPS crosses this Kickdown Hi, the shift pattern looks at the KICKDOWN for the given commanded gear to UP or Downshift the trans. It does NOT look at the Tables. Each calibrator, well most of us, always set the tables the same as the Kickdown so when we looked at our shift lines in Excel spreadsheets it was the same and the best for us to observe/correct/suggest changes. Now, as soon as the TPS crosses the Kickdown LO TPS cal, the shifting resorts back to the tables.


I think I understand this but I want to make sure. What you are saying is that when TPS >= "TPS to Enable Kickdown", it resorts to the "Kickdown" tables, otherwise it uses the "Normal Mode" shift tables, correct?

It looks like the 7427 bins do not use "Upshift RPM vs Shift" as they are all zero'd out. This is whats confusing me. Is there a way to enable/utilize this table or do I need to calculate the RPM limiter as a function of MPH..? ie: based off trans gears/ gear ratio/ tire size etc..and then output the results to "Upshift MPH vs Shift" .. ?

I found "RPM to Enter Fuel Cutoff" but since I'm no longer using TBI to control fueling this is useless.


Thanks again for the responses guys!!

[RobertISaar]

009F seems to be the byte used in 0E for the MNP switch.

L5453 FDB $009F ; 59, PATTERN, MNP PATTERN
;
; b7 (not used)
; b6 (not used)
; b5 (not used)
; b4 (not used)
;
; b3 1 = ILLEGAL PATTERN REQUESTED
; b2 1 = 'MANUAL' PATTERN REQUESTED
; b1 1 = 'PERFORMANCE' PATTERN REQUESTED
; b0 1 = 'NORMAL' PATTERN REQUESTED
;-----------------------------

there aren't too many places where it is stored to.... DTC77 also is applicable to it.

i can't find any applications from the factory that used it though, so finding out the pin scheme required is going to be interesting.

[EagleMark]

It looks like the 7427 bins do not use "Upshift RPM vs Shift" as they are all zero'd out. This is whats confusing me. Maybe something is wrong with your bin? Or XDF? Or it's a manual?

The "Upshift RPM vs Shift" is used in WOT as well or after MPH qualifier has been met. It's in the KickDown Mode Folder.

Upshift/ Downshift MPH vs. TPS is in Normal Mode Shift Folder.

EDIT: Ooops! This is a 4l60E I looked up in $0D

[RobertISaar]

if upshift RPM is set to 0 when in kickdown, then kickdown shiftpoints are entirely controlled by MPH. it wouldn't be the first time i've seen it in a factory calibration.

[dubwise]

What is the logic if I set the "Upshift RPM vs Shift" .. or is it used?

Basically I'm trying to figure out the best way to go about setting the shift points / rev limiter under the 4L80E section..

[billygraves]

..............

[RobertISaar]

that may explain a few things...... like why TCC PWM solenoids have almost always been operated at 32Hz in every application that i've looked at. the PCMs look like they have always been capable of 64Hz, but i imagine that being a near-exact multiple of 20Hz could cause issues...

this may complicate my 7730 TCM project a little.... i may have to have another microcontroller watch a 32-64Hz signal that i output from the 7730 and do some frequency modification while keeping the target duty cycle.

[billygraves]

..............

[1BadAction]

009F seems to be the byte used in 0E for the MNP switch.

L5453 FDB $009F ; 59, PATTERN, MNP PATTERN
;
; b7 (not used)
; b6 (not used)
; b5 (not used)
; b4 (not used)
;
; b3 1 = ILLEGAL PATTERN REQUESTED
; b2 1 = 'MANUAL' PATTERN REQUESTED
; b1 1 = 'PERFORMANCE' PATTERN REQUESTED
; b0 1 = 'NORMAL' PATTERN REQUESTED
;-----------------------------

there aren't too many places where it is stored to.... DTC77 also is applicable to it.

i can't find any applications from the factory that used it though, so finding out the pin scheme required is going to be interesting.

I've wanted to do this on my 7060 ($D8).. The bin has tables and LOOKS like it would work, but no clue how I would go about tracing it down. I'm also working under the assumption that it would be a momentarily grounded pin that switches between the modes. Guess I could start grounding random pins to see if my shift patterns change. :yikes: (quick, someone invest in reman 7060s) :laugh:

I guess I just can't shake the idea that there is a completely setup tow/haul mode in my factory ECM that I'm not using. Although I suppose it may be something vestigial that never was completed.

[RobertISaar]

gah.... i wouldn't recommend that.... and if i had to guess, i would expect a 3-position switch. the DTC for it shows a timer for invalid signal, so i don't think a momentary switch would make sense.

what i would do is follow the code far enough back to see where it is getting those mode determinations from.... if it is coming directly from a port on the processor, then you could follow the circuit(s) out to the connectors and you'll know what needs connected and how. if it coming in over SPI/SCI, then things get more fun.

[1BadAction]

The reason I say momentary ground, is that's how the LT1 computers did it, and even the 99+ LS1 PCMs have a setting for a depreciated "mom to ground" tow haul mode. Guess you could look at the LT1 programming and see if they have the same modes present?

[dubwise]

Thanks again for the responses guys..

1BadAction- Where did you get the $D8 def for the 7060? If you could point me to it that would be awesome.

RobertISaar- Where is the code for the 7060 located? I would like to dig through it for fun to see what I can come up with for the performance / tow mode.

[RobertISaar]

i don't appear to have a hack for D8... was one ever released?

[1BadAction]

Thanks again for the responses guys..

1BadAction- Where did you get the $D8 def for the 7060? If you could point me to it that would be awesome.

RobertISaar- Where is the code for the 7060 located? I would like to dig through it for fun to see what I can come up with for the performance / tow mode.
Stock $D8 BINs attached. One for the HD Suburban (BAMT) and the other from a 454ss (BAMY). BAMY is a much better starter tune.

[1BadAction]

i don't appear to have a hack for D8... was one ever released?
No idea, I've been using the AWBK Hack and the BAMY_CAL from the same PCM. Not sure what's different but the items I've added to the XDF all seem to line up and work correctly. IAC deadbands, O2 limits, etc.

Are CAL files the same as Hacs?

(EDIT: attached both)

[billygraves]

........

[1BadAction]

Longer gear holds and more spacing between up/downshifts when towing. I'd likely use a table close to stock for the tow/haul, then the normal tables would have my day to day shift pattern, which makes the truck FEEL more responsive.

In the 7060, $D8 Masks, the "Performance mode" Shift tables are all there, and they are complete. The do indeed look like performance tables, not hot mode tables like the later trucks have.


Why do you want to use the Perf Switch? Just asking..... One comment in this. If you see this in the calibration listing or your BIN/XDF, I would look into a few things first. What pins are the PERF Sw meched onto @ the PCM/TCM? If it is a NON-momentary sw, will the switch change, show up in the ADX or data stream? (Does it work?) Are there DIFFERENT 1-2, 2-3, 3-4 Upshift tables,Downshift tables and Kickdown calibrations listed? Will the DTC Function in the Illegal postion and set the diag code?

[RobertISaar]

No idea, I've been using the AWBK Hack and the BAMY_CAL from the same PCM. Not sure what's different but the items I've added to the XDF all seem to line up and work correctly. IAC deadbands, O2 limits, etc.

Are CAL files the same as Hacs?

(EDIT: attached both)

hmm..... all calibration, no algorithm..... i'm not seeing the alternate shift mode status bytes in the datastream either, so finding the code that deals with it won't be as simple. assuming the perf vs normal tables are done like everything else from the era, at some point, X will point to the beginning of one of them and then offset via a ABX when necessary. that will depend on how the tables are arranged in the calibration too.....

[EagleMark]

No idea, I've been using the AWBK Hack and the BAMY_CAL from the same PCM. Not sure what's different but the items I've added to the XDF all seem to line up and work correctly. IAC deadbands, O2 limits, etc.

Are CAL files the same as Hacs?

(EDIT: attached both)I would use the Bamy_cal.src.

All Axxx were superceeded to Bxxx and technically this is $D8, but we left the files as $85 when I did the initial work on $85 files when I had a truck to work on a few days... story here...
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?807-16147060-85-Superceeded-to-D8

[1BadAction]

I would use the Bamy_cal.src.

All Axxx were superceeded to Bxxx and technically this is $D8, but we left the files as $85 when I did the initial work on $85 files when I had a truck to work on a few days... story here...
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?807-16147060-85-Superceeded-to-D8
I just re-read that whole thread, funny how all those posts make so much more sense once you know your way around these bins/masks/etc.

I started with the BAM* based tunes a few months back when I fixed the cam timing issue and had to start all over again. You can't tell by looking at the tune in TP, but the Bxxx tunes are just... Better. Still quirky but not nearly as bad as the Axxx. No wonder all of the A's were superseded.

[billygraves]

.....................

[1BadAction]

I can't help but bring this back up... With a 7060 ECM, how, without a way of knowing Low or High range, can a 4L80E shift correctly when the transfer case is in 4WD low?

[delcowizzid]

if you are taking speed output off the trans before the transfer yes

[dubwise]

I can't help but bring this back up... With a 7060 ECM, how, without a way of knowing Low or High range, can a 4L80E shift correctly when the transfer case is in 4WD low?

I like where you are going with this, but did the 7060 come in any trucks that had 4wd? If it did, I would assume one pin would go to ground when you shifted the lever into 4lo....

[brian617]

I like where you are going with this, but did the 7060 come in any trucks that had 4wd? If it did, I would assume one pin would go to ground when you shifted the lever into 4lo....

Looking for the same answer on 427 PCM. Never found anything in the wiring diagrams to support this theory. The 4wd 4L80's use the speed sensor signal from transfer output and have the transmission output shaft speed sensor hole dummy plugged. Something has to tell the PCM your'e in 4low but I couldn't ever find it.

[1BadAction]

I like where you are going with this, but did the 7060 come in any trucks that had 4wd? If it did, I would assume one pin would go to ground when you shifted the lever into 4lo....
Yes. 91 Crew cabs 2500s and Suburbans.

[RobertISaar]

Looking for the same answer on 427 PCM. Never found anything in the wiring diagrams to support this theory. The 4wd 4L80's use the speed sensor signal from transfer output and have the transmission output shaft speed sensor hole dummy plugged. Something has to tell the PCM your'e in 4low but I couldn't ever find it.

94 K2500 5.7 4L80E diagram

http://i.imgur.com/gyUc81s.png

would this have been a 7427 application?

[Nasty-Z]

Yes , Pin F8 on a '7427 is the 4X4 Low range signal , X-fer case has a ball switch that sends a signal to the PCM when in 4 low , thereby modifying the shift firmness .

At least that is the way I understand it , works that way in my '93 3500 .

TOM

[brian617]

I think you found it! My ShopKey has F8 blank, but when I looked at the 7747 to 427 conversion chart F8 is listed as 4wheel low input for 427. Drove my self crazy looking for that couple months ago. THANK YOU!

[brian617]

Yes , Pin F8 on a '7427 is the 4X4 Low range signal , X-fer case has a ball switch that sends a signal to the PCM when in 4 low , thereby modifying the shift firmness .

At least that is the way I understand it , works that way in my '93 3500 .

TOM

The ball switch is for front axle lock. Must be another source for 4 low???

[Nasty-Z]

The ball switch is for front axle lock. Must be another source for 4 low???

There is a pin switch that is supposed to be for front axle lock (not used on my truck as I use a different setup to lock the diff) , there is a ball switch for the indicator lights and there is also a ball switch that only comes into effect when 4 low is selected. Possible different Xfer cases use different switch configurations ? Mine is a BW 4470

TOM

[brian617]

There is a pin switch that is supposed to be for front axle lock (not used on my truck as I use a different setup to lock the diff) , there is a ball switch for the indicator lights and there is also a ball switch that only comes into effect when 4 low is selected. Possible different Xfer cases use different switch configurations ? Mine is a BW 4470

TOM

I'll have to do some more looking. Most of the manual shift transfer cases 88-94 maybe 95 use the two wire ball switch on the t-case to send power to front diff two wire metal actuator, as I have fix several of "no 4x4" problems this way including my own truck, after 96 they started using the black plastic front actuators that were 5 wire I believe and they may differ. Maybe there is a three wire ball switch? Cant remember any of the manual shift cases having more than one switch on them, but i'll dig around tomorrow and see what I can find. Come to think of it, i've even fixed a 98 model 4l60e manual shift transfer replacing the two wire ball switch same situation.

[Nasty-Z]

I'll have to do some more looking. Most of the manual shift transfer cases 88-94 maybe 95 use the two wire ball switch on the t-case to send power to front diff two wire metal actuator, as I have fix several of "no 4x4" problems this way including my own truck, after 96 they started using the black plastic front actuators that were 5 wire I believe and they may differ. Maybe there is a three wire ball switch? Cant remember any of the manual shift cases having more than one switch on them, but i'll dig around tomorrow and see what I can find. Come to think of it, i've even fixed a 98 model 4l60e manual shift transfer replacing the two wire ball switch same situation.

I will double check as well, I do know that when in 4 low Pin F8 sees a ground , when I did the conversion I thought the signal came from the ball switch on the transfer case . It has been a few years since I did the swap , BBC in place of the 6.5 Diesel and '7427 to control it all. CRS is acting up again .........

TOM

[1BadAction]

Well at least we have one question answered. :laugh: I guess I'll need to drop my old hard drive in this computer, pull up the service manuals for the MT1 trucks and see what I can find.

[brian617]

Well at least we have one question answered. :laugh: I guess I'll need to drop my old hard drive in this computer, pull up the service manuals for the MT1 trucks and see what I can find.

One answered and five more asked :laugh:

[brian617]

Turns out the 4L80 uses a three wire ball switch on the transfer case with the third wire making the ground input to F8 for low range.:jfj:

[Nasty-Z]

Turns out the 4L80 uses a three wire ball switch on the transfer case with the third wire making the ground input to F8 for low range.:jfj:

You beat me to it, but you are correct , that is the way my 4470 works . Checked this morning.

TOM