WS6HUMMER

iTrader: (19)

I've been over the tune and can't figure out what's going on. I have the WOT rpm & speed adjusted to shift @ 60mph & 4650rpm & the PCM will not command the shift. This truck has 4.88 gears & 37" tires & the speedo has been calibrated to reflect gps accuracy. The owner of the truck did have the trans rebuilt & the builder did just a standard build but did turn up the force motor current so high that it sometimes barks the tires on the shift. Another factor is that even though in the tune I have it commanded to shift @ 4650 RPM, the ecu doesn't send the signal for 3rd gear till later, so I don't know if its a line pressure issue or not.

01ssreda4

iTrader: (96)

You need to make sure all MPHs for full throttle match in all tables. Also, program the full throttle mph trigger first and rpm second but do them right. Full throttle doesn't need to be at 4k something rpms. You need to log actual RPM vs speed so you know where to set it. If I want my car to shift at say 6500 or 65 mph I must command an earlier shift. So let's say 59 mph = 5900 rpm and 62 mph = 6200 rpm, I would command 59 mph and 6200 rpm for a 6500 actual shift with a 6800 limiter. The PCM needs to see speed first, rpm second, then has to have time to send the command and the Trans complete it. Can you post a tune file so we can look at it?

WS6HUMMER

iTrader: (19)

Yeah I've been down the road of the shift speed & rpm not matching before so that was the first place I looked and it all looks good to me. I'm setting the 2-3 shift to 4650 RPM because that's what the owner of the truck wants & I'm trying to make him happy. No matter how soon I tell it to shift It still shift's @ 70+ mph & almost 5800rpm. You can look at the trans-current gear and the pcm is not commanding the shift for some reason & I have a funny feeling it has something to do with the trans builder cranking up the force motor current (manually) before I got my hands on it.

01ssreda4

iTrader: (96)

So i know.....What's the desired shift rpm? When is it actually shifting? What's the limiter? I will look at it when I get to a laptop and report back.

nj02z

iTrader: (6)

Where is your wot % enabled?

WS6HUMMER

iTrader: (19)

Desired RPM is 4650, It's shifting almost @ 5800, & the limiter is 6100 in the ETC vs RPM table, 6200 in the normal table. Thanks.

WS6HUMMER

iTrader: (19)

Stock settings, 93% enable, 90% disable.

nj02z

iTrader: (6)

Does that need to be met also?

WS6HUMMER

iTrader: (19)

Yes it must be met.

01ssreda4

iTrader: (96)

Wait, you want it to shift at 4600? I'm not asking what it's set at, I'm asking where would you like it to shift....

01ssreda4

iTrader: (96)

If wot wasn't met wouldn't it shift early? Something isn't jiving here, I bet it's something simple.

nj02z

iTrader: (6)

What if you try lowering enable?

WS6HUMMER

iTrader: (19)

Yes he wants it to shift at 4650rpm, this is a jacked up truck with 37" tires and 4.88 gears. Yes it is hitting 100% TPS, check out the log I posted.

01ssreda4

iTrader: (96)

Right off the bat: Part throttle shift, all 4 tables dont match in the 94-100% columns- normal performance cruise hot should all match each other. Full throttle normal, performance and hot dont match either other either. Full throttle rpm tables dont match. Get all these sync'd 100% in the full throttle region.

Up-Shift pressure looks a tad weak, force motor is ok, shift time Id run .250 in the upper half of the table.

4579rpm=60mph. You are commanding both triggers at almost identical times. MPH needs to be met first. Lower the 60mph down to say 55 to give it some breathing room, then it will meet that criteria and shift off of rpm only.

WS6HUMMER

iTrader: (19)

Part throttle has nothing to do with the WOT tables. Performance & hot are supposed to be different, the stock tune was & the whole reason for having a hot table is for a safety net to protect the trans. Up shift looks weak but do you not understand what it means when I said that trans builder turned up the force motor current manually? You can't see it in the tune because its a mechanical adjustment but this trans has max line pressure ALL the time.

4650=60mph see.

mrvedit

Wshummer: While you are correct that the "Hot" table can be very modest to protect the trans, I also like to set the Normal and Performance tables the same.
We strongly suggest that you set the 94%-100% column in the Partial Table to agree with the WOT table. (However I think you do - I looked at it last night).

HOWEVER I absolutely agree with the 01ssreda4 the the WOT MPH needs to be set much lower at least to 55MPH (which then also means setting the Partial Throttle table to match). I set my MPH to about 15% lower than the max RPM I want to experiment with. That way at the track I can experiment by only setting the WOT RPM table and ignoring the WOT MPH table.

01ssreda4 has probably helped many dozens of people with similar problems and his suggestions nearly always solved it. Indeed your log that 4650==60MPH guarantees that you will have problems using those values in the tune.

WS6HUMMER

iTrader: (19)

Thank's I'll give that a try & let yall know how it goes. I don't think I understood what 01ssreda4 was trying to say until just now, thank you both for the helpful suggestions.

01ssreda4

iTrader: (96)

I do understand the differences in the tables believe me. I've always been taught for the truest most consistent auto Trans behavior (wot, obviously not wanting to hit the limiter) is to sync all the columns. I realize wot is separate from part throttle, but there is still 94 and 100 throttle columns on the part throttle table. If the wot 100 is on a different table, it makes sense for them to match so that no matter where the computer reference the behavior is predictable.....and so on and so fourth. I'm not trying to pick apart your tune but we are here to pick apart your tune

WS6HUMMER

iTrader: (19)

LOL! Thanks, what you're saying makes sense, & I do appreciate your help. I'll post results sunday when I take another stab at it.

01ssreda4

iTrader: (96)

Cool man. Hope it works out for you. If it doesn't feel free to give us an updated tune and log and I will take another look.