chip reprogramming after gear change
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 810
Likes: 4
From: Austria
chip reprogramming after gear change
hi all, title says it
i have done chips myself, my question is, can i reprogram the chip, when i step up from 3.33 to 3.73 is there a table where i can do this
also, i have FX3..will this be affected?
what i see, the VSS send its signal to the ECM, the ECM generates the signal for the CCM, which make the speedo readings
thank you
i have done chips myself, my question is, can i reprogram the chip, when i step up from 3.33 to 3.73 is there a table where i can do this
also, i have FX3..will this be affected?
what i see, the VSS send its signal to the ECM, the ECM generates the signal for the CCM, which make the speedo readings
thank you
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Re: chip reprogramming after gear change (corvette90)
It should be the road speed constant in the constants table of your tuner program. That is the number of pulses/mile that the ECM sees to determine speed
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 810
Likes: 4
From: Austria
Re: chip reprogramming after gear change (tjwong)
ive seen this table...its 4007 pulse per mile
how will i have to alter the value??
is this an ECM output value or input value??
would be interested, how different rear ends ( factory installed) are programmed in the ecm..or do they use different VSS gears in the tranny??
thank you
how will i have to alter the value??
is this an ECM output value or input value??
would be interested, how different rear ends ( factory installed) are programmed in the ecm..or do they use different VSS gears in the tranny??
thank you
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Re: chip reprogramming after gear change (corvette90)
I checked several GM calibrations I have for a given year. It appears that this constant is always set to 4007. And it doesn't matter if the car has 3.07 or a set of 2.** gears. It would appear that the cars with different gears must have a different calibrated VSS. That would explain that the road speed constant is always set to 4007. I remember in the old days that when one would change gears or tire sizes one had to get a different VSS box.
The value is just a constant that the ecm uses to calculate speed by. It sees a square wave pulse from the VSS sensor that is driven by the tailshaft in the transmission.
[Modified by tjwong, 8:25 AM 6/21/2004]
The value is just a constant that the ecm uses to calculate speed by. It sees a square wave pulse from the VSS sensor that is driven by the tailshaft in the transmission.
[Modified by tjwong, 8:25 AM 6/21/2004]
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
Re: chip reprogramming after gear change (corvette90)
You'll have to get the proper speedo gears for the VSS. I don't believe it was until later on in the $EE years that you could alter gear ratios in the computer directly.
