P59 cruise control calculation

[tyeler18]

Does anyone know how the VSS calculation is done on the P59 PCM? T56 should be a 17 tooth reluctor as far as I'm aware for everything except the SSR? All the Tune files for P59 cars (04 vette, GTO, CTS-V etc) all show a 40 tooth reluctor. P01 PCM's seem to show 17 tooth like expected.

I have a swap car with a P59, DBW, and T56. My cruise works in 1-5th but will not set in 6th at all. Speedo reads correct in VCM scanner, buttons for cruise all switch to yes in 6th. I tried changing the VSS to 17.000 assuming since my OS was original an auto car it was just setup wrong, but then the cruise doesn't work at all. I have a new calibration i'm going to test on the way home from work that has the VSS and VSS/mile etc hand calculated out, but even those calculations vary between P01 and P59. The P01 camaros show a roughly 800 trans revs/mile where the P59 cars seem to be multiplied by the rear gear ratio putting them in the 2-3000 revs/mile for some reason. The description for calculating tran revs/mile is pretty horrendous so I'm not sure if I'm supposed to be inputting the 800 trans revs/mile or multiplying by my rear end ratio. Also i'm confused why all the factory P59's show 40 tooth VSS reluctors.

5-7-21 e30 stock injector working rom pre 42lb flash.hpt

Here's my current OS with my currently working 1-5th cruise. The cars an fbody LS1 t56, 24.7" (245/40/17) tire and a 3.73 rear gear. Cruise works up to 100mph (highest I've tested) in 5th but will not work at any speed in 6th

[tyeler18]

Tried a couple different settings and can't seem to get this to work. The posted file above works 1-5th no issue, 6th is dead at any speed. If I alter from there it pretty much just doesn't work at all. Is there an OS difference between vehicles for cruise? I have 12577325 for my speedo OS and it looks like an 04 vette uses 12579127 for the speedo, maybe there's programming differences between them? I'd segment swap the vette OS in but don't want it to interfere with any other portions of the tune without knowing if it'll work or not. Any insight?

One more thing is that im currently set to GMT610 on the system settings, if I change to Y i'd think it would have a similar effect? I'm mostly concerned with messing up my fan and A/C settings as those both work fine as is, I am using a trinary A/C switch so I'd think that should all function normally on either setting.

[tyeler18]

Sent an email in to Hptuners support which was just as worthless as I expected. I guess I'll just start dicking around with these settings until something happens or I get angry enough to ditch for holley's in all my cars.

[Dark4Watch]

Did you ever figure it out?

[tyeler18]

Did you ever figure it out?

Nope never did, I swapped to a holley a while after and have just switched over to a rebel specifically to get cruise control again which is wonderful.

[RDF1]

245/40/17 and 3.73s with a T56 should be 121744 Pulses per mile [(ECM) 9000] and 3839 Rev/Mile ([ECM) 5002) for 17 tooth T56.

Yours has 3538 TOS in 5002 cell and 51777 PPM in 9000 Cell.

The Cruise control module only accepts a range of pulses that equal 25mph up to 125mph. (i dont have the info in front of me to explain the amount of pulses that is).

But the Formula is ECM 9000 / ECM 5001 = ECM 5002.

ECM 9000 is only for the cluster
ECM 5002 is for the PCM internal calculations for Auto trans shifting and cruise control pulses output to CCM.

I use the Cruise control modules from the silverados that have cable throttle and wire them up and send them a PPM signal from Holley ECU for cruise control to work.

[Dark4Watch]

Hey I did a 2005 ctsv segment swap and it works in all my gears now , for anyone in the future I hope it works for you as well .