Stock Shift Tables......

2kwik4u · Post by **2kwik4u** » Thu Jun 08, 2006 11:44 am

The following images are pulled from a file located Here. They are for a bone stock 4.3/4L60E combo.

I'll have more and more posts coming and some explanations on how it all works.

First off Shift modes. There are 4 modes available. Normal, Performance, Hot, and Cruise. Performance is enabled by a tow/haul button in our application. Hot is enabled whenever tranny temp exceeds a preset limit (I believe it's currently set at 180*, although I will have to verify, and then update this part). Cruise mode is obviously anytime that the cruise control is on. Normal is anything that DOES NOT meet the above citeria.

The first of which is the VSS upshift tables for part throttle. Across the top you have the 1-2, 2-3 and 3-4 upshift tables. Each row represents the TPS location, and each column represents a shift mode. When the truck reachs these VSS signals the tranny is commanded to shift to the next gear. Under WOT (WOT is considered anything above 55% TPS in 4wd applications) both these VSS tables, and the WOT table values must be met in order for the tranny to shift to the next gear. You can find these values in the table to the lower left of the screen shot.

Also in the lower right corner you will see the 2nd gear 1-2 shift speeds IF you are commanding a 2nd gear hold (Gear selector in 2nd) it wil stay in second unless you cross that VSS at that given TPS. A zero'd value indicates that cell is to not be used. SO in this example you can see that only 93.5% and 100% throttle will result in the tranny shifting into second, which the tranny is already in second, so it's basically a moot point, but thought I should include that for clarity.

Click thumbnail to Enlarge

Here is the WOT upshift tables. Remeber anything over 55% throttle in 4wd results in using these points. WOT RPM, and 100% TPS on the VSS maps MUST be met before the tranny will upshift.

Click thumbnail to Enlarge

Thats a good start.....Give me a few minutes and I'll get started on the Downshift tables.

2kwik4u · Post by **2kwik4u** » Thu Jun 08, 2006 11:58 am

OK heres some of the Downshift tables. It takes three pieces of information to induce a downshift. X RPM, X MPH, and X TPS. If all three of these are met then the PCM will command a downshift.

The first set of tables are TPS vs Mode. TPS in the Rows, and Tranny mode in the columns. The data is VSS. Remember these work with the tables below to initiate a downshift. From left to right, they are 4->3, 3->2, and 2->1. The table at the bottom is more WOT downshift controls. Remeber anything over 55% is considered WOT while in 4wd.

Click thumbnail to enlarge

Here are the TPS downshift tables. These read the same left to right (4->3, 3->2, 2->1). The rows are MPH, and the columns are Shift mode, with the Data being TPS. Remember these work with the tables above to induce a downshift. All conditions must be met for the downshift to be initiated.

Click thumbnail to enlarge

Thats enough for today. I'll cover some more stuff tomorrow, and give some more explanations. Most likely I'll cover some of the TCC lockup, and unlock tables, and maybe some shift time stuff to

2kwik4u · Post by **2kwik4u** » Fri Jun 09, 2006 4:03 am

Would've expected some more interest from this......Anyone want me to continue?

GeorgesBlazah · Post by **GeorgesBlazah** » Fri Jun 09, 2006 4:07 am

Keep it coming. Im gonna read it when I get home from work tonight

.

2kwik4u · Post by **2kwik4u** » Fri Jun 09, 2006 4:31 am

Here it comes

Today I'll cover TCC (Torque Converter Clutch) apply and release.

The tables below are the TCC apply speeds. Assuming part throttle operation, when these speeds are met the converter will apply the lockup clutch at these speeds. The tables from left to right are 2nd, 3rd, and 4th gear. Notice that in second the converter is set to lock at 235 in all tables except performance. A number that is obviously unreachable. This is a good example of manipulating the values to obtain a desired result. Since the truck will never reach 235mph in second, the convertor will never lock.

As always, click to enlarge the picture.

2kwik4u · Post by **2kwik4u** » Fri Jun 09, 2006 4:39 am

The tables below are the TCC unlock/release tables. I believe these to be setup in a manner so that one or the other is required to unlock the TCC, NOT BOTH as in the WOT shift tables in the posts above. So if the conditions in either map are met, then the TCC unlocks.

On the top row you have the MPH tables. At a give TPS, and given MPH the convertor will unlock. If you notice the tables at the bottom are all 100%. The PCM doesn't really need these values since most of the unlocking is controlled with the top set of tables, however they are there as a failsafe. Again it runs 2nd, 3rd, 4th from left to right.

Click thumbnail to enalarge picture

killian96ss · Post by **killian96ss** » Fri Jun 09, 2006 5:04 pm

2kwik4u wrote:Would've expected some more interest from this......Anyone want me to continue?

Yes, but I seem to have a problem when I click on the images to enlarge them. They all appear with broken letters and numbers making it very hard to understand what I'm looking at.

Am I the only one having this problem?

Edit, nevermind I think I figured it out.

I just needed to enlarge the pictures even more to read them.

Steve

daevans315 · Post by **daevans315** » Sat Jun 10, 2006 7:20 am

I was just reading through these and thinking about the tow haul button and then something popped into my head. These tables are why my 97 s10 will not go into OD over 100mph. On the track its not a big deal but when we are running back and forth to the track (obeying all local traffic laws

) I hate to run very far over 100 and usually wave good by to the group if they decide to do that because 97 will not drop into OD until the spedo comes back off the peg even with your foot off the accelerator. (That and the fact I can't afford the speeding ticket or really think it’s a very good idea.)

Has anyone with a crew had the lack of common sense and a modified top speed limiter to see if it does the same thing?

No OD over 100mph? If I'm deciphering the shift map correctly it looks like at 103 and 100% throttle it would go ahead and shift to OD.

2kwik4u · Post by **2kwik4u** » Sat Jun 10, 2006 10:27 am

daevans315 wrote:I was just reading through these and thinking about the tow haul button and then something popped into my head. These tables are why my 97 s10 will not go into OD over 100mph. On the track its not a big deal but when we are running back and forth to the track (obeying all local traffic laws ) I hate to run very far over 100 and usually wave good by to the group if they decide to do that because 97 will not drop into OD until the spedo comes back off the peg even with your foot off the accelerator. (That and the fact I can't afford the speeding ticket or really think it’s a very good idea.)

Has anyone with a crew had the lack of common sense and a modified top speed limiter to see if it does the same thing? No OD over 100mph? If I'm deciphering the shift map correctly it looks like at 103 and 100% throttle it would go ahead and shift to OD.

I'll be removing the limiter on my ZR5, and will check to see how it works.....

I'm also not 100% sure that these tables are the same on the '97's these are only for sure stock on '02+ trucks however I would suspect similar tables.

2kwik4u · Post by **2kwik4u** » Mon Jun 12, 2006 11:44 am

Sorry no updates today....Been busier than a one-armed-paper-hanger today......Dang work getting in the way of my fun.

daevans315 · Post by **daevans315** » Mon Jun 12, 2006 11:59 am

2kwik4u wrote: I'm also not 100% sure that these tables are the same on the '97's these are only for sure stock on '02+ trucks however I would suspect similar tables.

What was in my head and not on the message.. The 97 probably has a slightly different set of maps that will not allow OD to engage above 100 mph.

2kwik4u · Post by **2kwik4u** » Mon Jun 12, 2006 12:07 pm

daevans315 wrote:
2kwik4u wrote: I'm also not 100% sure that these tables are the same on the '97's these are only for sure stock on '02+ trucks however I would suspect similar tables.
What was in my head and not on the message.. The 97 probably has a slightly different set of maps that will not allow OD to engage above 100 mph.

OD wont engage at anything above 87% TPS on the current maps either with the stock limiter in place. The table reads 97mph from 87% up in normal mode, which ironically is 1mph higher than the limiter is set. Hot, performance, and cruise are all set to 235 from about 63% TPS up. It's obvious the stock computer programers didn't want this happening. I'll be changing this on my setup, as personally if I'm going that fast, with my foot that far into it I'm going to want the next gear......Although I can't vouch for this lasting on a stock tranny.

Also on the older 700R4's they were designed to NOT shift to OD during WOT, because the internals were not strong enough to handle it. The only exception I know of to this is the 700R4 that was in the Syclones and Typhoons. Built stronger than the 'vette 700R4, and with a noticably lower shift point, and higher stall convertor........