pcmhacking.net

hi guys, am new to all of this (within a few days) - so please be patient

basically at the moment i would just like to change where and when the TCC locks up. currently, when it does lock, the throttle pressure required to keep it locked means the car will gradually accelerate until i'm over-speed, and when i back off slightly it will unlock.. essentially it just makes it impossible to keep the car smoothly at 110 with it locked.

It feels to me, from the way the car drives, that the TCC becomes available only above a certain speed, and is only applied when the TPS reads above a certain amount..

i'd simply like it to be available after 105kmh, but only when below, for example, 20% throttle (not actually sure yet what the TPS reading is to just keep the car at 110kmh) - that way if i'm accelerating through third and fourth it won't engage, but when i back off to cruise it will lock.

am i correct in the way i understand the TCC works? does the MAP reading have anything to do with it?

if i understand correctly, i'll then try to work out what i think should be changed, and what it should be changed to, and i'll post what i come up with here. if somebody could have a quick look over it, let me know if it should work, or just tell me i should go apply for a job at a fast food place, that'd be great.

thanks!

have opened all the TCC stuff that seemed relevant, didn't notice any MAP related stuff at all, just speeds and TPS, so i'm guessing i've got the right idea, probably should have looked through the bin first.

i also realize getting the actual values needed is going to require some data logging, will do that soon enough - just playing around with the bin at the moment purely to familiarize myself

attached are the things i figure i should be changing..

The TCC is pretty much TPS based, few timers and temp settings but load is TPS as you have found. You can search in TP for 'TCC' items too - CTRL+F or under the tools menu, and parameter finder.

from what i gather - using the values from the screenshot i posted previously:

* from the 'Lock table TPS limit vs road speed' table:

- at 104-112kmh, TCC will lock if and when TPS% is above 44.92% and will unlock if TPS% reaches 62.89%
- at 112kmh+, will lock when above 48.05 and unlock above 69.92

my TCC will only ever lock up after 90kmh.. so i figure 'TCC road speed coast level', is the param that when reached, will allow TCC lock (providing the TPS% is within the corresponding table values)

i don't yet understand what the 'TCC road speed upper limit for lock' value of 70kph and it's lower limit value of 64kph are for.

and if i've correctly understood the above, and for example, want TCC only above 105kph and have found to stay at a constant 110kmh it requires 20% throttle - should i just change the 'TCC road speed coast level' value to 105, and lower the TPS% in the LOCK table from 44.92 down to 19, and if need be lower the UNLOCK table value accordingly?

i will probably need to find a sweet spot, i just want to know if i'm on the right track, as i don't yet have any way to test any of these changes.

thanks in advance.

Ttc lock upper limit is the speed you have to be doing for it to lock, the lower limit is the speed you the have to drop too before it will unlock

thanks for the reply..

that is what i initially assumed, (it seemed obvious), but it was just too coincidental that there was a value of 90 elsewhere and that is the speed at which mine locks at.. what exactly is 'TCC road speed coast level' used for then?

That is used to to select either ..
"TCC Params - TCC Coast release lock delay time Low road speed" and "TCC Params - TCC Low km/h coast load limit"
or "TCC Params - TCC Coast release lock delay time High road speed" and "TCC Params - TCC High km/h coast load limit".

So if vehicle speed is below "TCC Params - TCC Road speed coast level" then it uses the low speed items, above uses high speed items.