4l65e not shifting at wot

[ls1mike]

edited

[Taz]

Hello Mike,

I reduced the WOT thresholds to stock - it should shift now. You will need to reset the VSS shift speeds and shift RPM to desired values - looked like you had been manipulating these trying to get it to shift.

Speaking of stock settings - your shift pressures are stock, but the shift times and torque reduction (TR) have been set to zero. I prefer to increase shift pressures to protect the transmission, have brief (but not zero) 1>2 and 2>3 shift times, and adjust shift "feel" via TR.


Regards,
Taz

[Taz]

Sounds like a great transmission ... if this is a dedicated competition vehicle, then continue as you were. If however, this is a street driven vehicle, you may find having TR zeroed out may lead to increased driveline component wear and / or parts failure.


Regards,
Taz

[Aloicious]

yeah, give Taz's changes a try, the only thing I could see was your WOT TPS% setting in D1206 was set to 100%, but that value description says: "When the throttle position (TPS) moves above this value, the PCM uses the WOT shift tables." so if it's set to 100% you can never go ABOVE that value which i believe would prevent it from using the WOT shift values you had....but I'm not much of a automatic guy. let us know how it works out.

[ls1mike]

2>1 table didnt help. I moved the WOT threshold as low as 60% and it just made everything act weird and it still would not shift. I'm going to blow my engine up trying to fix this the overrevving already ate a tensioner.

[Taz]

Hello Mike,

"Gremlins" in a new configuration can be frustrating ... no need to rev the engine to the moon ... if it doesn't shift when it should, stop and re-evaluate things.

There are many things that could be going wrong ... will try and help eliminate variables. Your existing tune looks like it is from a 5.3 L, and the engine displacement and other parameters are still setup for a 5.3 L. This may have no effect on transmission shifting, but will need to be adjusted in future regardless.

To facilitate a "clean slate" approach, the tune attached below is a 100% stock 1999 Silverado LQ4 6.0 L engine tune (using the same OS), with a Camaro 4L60 transmission calibration segment (TCC will remain locked on throttle lift - coasting) and a Silverado 4L60 transmission diagnostic segment.

I reset the transmission parameters to 100% stock 1999 Silverado 4L60 parameters. I also set it up for the tire diameter (29.56) and gears (3.73) from your original posted tune.

This should be a solid base tune to work from.


Regards,
Taz

[Taz]

You also indicated some odd behaviour from the Tach. For a WOT shift to occur two conditions must be met - shift RPM and shift speed (usually prefer shift speed to be met first, that way shift RPM will control the actual shift).

A log of what is happening when the transmission should be shifting would be helpful.

Attached below is a PID of transmission related parameters.


Regards,
Taz

[Aloicious]

the good thing about tuning yourself is that you can try out whatever you want and always be able to return it to what you had, it wouldn't hurt to take taz's LQ4 tune, copy your VE/spark tables from the one you have been using, and try it, and use that one as a base for doing your own tuning, then as you get the shifting how you like, you can either copy any other parameters over to your tune, or if its not working you could always sitch back too....

you mentioned shifting problems after he tuned it as well. are you sure its not a mechanical trans problem?

BTW yoiur clip is great, your truck sounds like a jet taking off with your blower on there....something to think about in the future, but you might want to look into a custom operating system to cover the VE while you're in boost since the stock VE doesn't.

[Aloicious]

let us know what you find out

[joecar]

I would set these:
- Throttle Kickdown tables to 100% everywhere;
- the WOT downshift speeds to be below the WOT upshift speeds by at least 5 mph;

if either of those are not just so, they can prevent a WOT upshift.