Speed Limiter / No Throttle Response - 2014 CTSV

[jchambers]

2014 Cadillac CTSV Coupe / A6. Hitting a speed limiter right about 117MPH and 5850RPM. All RPM limits and torque limits have been raised well beyond this so I figure the limit is somewhere in the speed limiters. Switched from GMLAN to Calibration and maxed out values and I get no throttle response at all. Switch back to GMLAN and it takes 6 or 8 key cycles to get throttle back. Will do the same thing if I just try to adjust tire size (owner has gone from 26.05" to 26.7" tires). The GMLAN => Calibration has always worked in the past.

Flashing back to the starting file, once I can get the throttle responding again the ABS seems to be confused for a bit and will rapidly modulate the rear brakes at about 60MPH on the next pull. Takes several key cycles again to get the ABS to buy into the situation and let me make a pull up to the limit point again.

OS is 12656245 and TCM is 24264923. 2014 CTSV coupe, 6.2L S/C A6

Would also like a stock file for this if anyone has one.

[Higgs Boson]

try not maxing the values, it has done weird things on other vehicles. otherwise, send you file and info to support for debugging.

[veee8]

Try maxing commanded gear mph and rpm in the trans diag tab. Especially important if using the scanner for trans control on the dyno. There should be no problem setting to calibration and maxing out the top speed limiter on these cars.
Don't forget the rev limiters in the fuel cutoff as well. Cold tab, the V is biased towards IAT a bit, and not totally coolant temp.

[Higgs Boson]

Try maxing commanded gear mph and rpm in the trans diag tab. Especially important if using the scanner for trans control on the dyno. There should be no problem setting to calibration and maxing out the top speed limiter on these cars.
Don't forget the rev limiters in the fuel cutoff as well. Cold tab, the V is biased towards IAT a bit, and not totally coolant temp.

have you tuned a torque based ecm with 2.25 yet? There is no VCM control through 2.25 scanner and maxing the values in the speed limiter section does cause issues, it is well documented.

[veee8]

have you tuned a torque based ecm with 2.25 yet? There is no VCM control through 2.25 scanner and maxing the values in the speed limiter section does cause issues, it is well documented.

Yes I have, I was one of the topic starters when I came across it early on.
This application is E67 "old school" and shouldn't have any issue with maxing them out. I have tuned several 14 V's with that OS and maxing out the limiter is what I personally do.
Different ballgame on the new torque based PCM stuff as we know.

[veee8]

BTW OP this is in the wrong sub forum. Should be in Gen 4

[Higgs Boson]

very good, I haven't seen the file, wrong computer.

[jchambers]

Try maxing commanded gear mph and rpm in the trans diag tab. Especially important if using the scanner for trans control on the dyno. There should be no problem setting to calibration and maxing out the top speed limiter on these cars.
Don't forget the rev limiters in the fuel cutoff as well. Cold tab, the V is biased towards IAT a bit, and not totally coolant temp.

Will get the car back and give this a try. Do you happen to have a stock read from this OS? Others have been in this car before me (Hennesy and another) so I'd to see what has been changed.

Is there any reason that I shouldn't be able to correct for the tire size?

Thanks

[veee8]

Here you go. You still have a lot of torque management etc.. on that file you posted.


2014 CTSV A6 stock.hpt