~IMPORTANT~ IMPORTANT things to look at when changing Speedo.

[wait4me]

Hi Guys,

When recalibrating your speedometer you need to check the values and make sure you are putting in valid information for you application.

There have been 2 instances on corvettes where the pulses per revolution have been modified to a very high number which made the pcm go into a cpu 100% loop. The cause is by playing with the speedometer calculator and unchecking the "Transaxle" box.

IF YOU HAVE A CORVETTE, YOU NEED TO LEAVE THAT BOX CHECKED! If not it will change the calculated pulses per revolution to 40 making the H0101 table go to an obscene value.

An update will be posted that will force the transaxle box to be not changeable from now on. Also a Max H0101 value will now be in made so only reasonable values can be entered....


IF anyone has any problems or questions, Call or email me and i will answer your questions. Also if you somehow have a non responsive computer then send it my way and i will fix it and ship it back out for free.

The only vehicles that may be effected with this are only certain corvettes and only if you unchecked the transaxle box when modifying speedo cals.

Thanks

[Boost]

Thanks for the info. SSR is also affected.

[SSpdDmon]

There may be some potential problems with making the option not an option any more like for those who are using a Corvette PCM, dash & powertrain in another vehicle or those who swap in a solid axle to the C5. Maybe a nice, big, flashing warning box could pop up instead? Just trying to think ahead...

[Blacky]

There may be some potential problems with making the option not an option any more like for those who are using a Corvette PCM, dash & powertrain in another vehicle or those who swap in a solid axle to the C5. Maybe a nice, big, flashing warning box could pop up instead? Just trying to think ahead...

The transaxle checkbox is based off of the VIN, so if you also change the VIN to a non-corvette VIN then the checkbox will not be checked.

Regardless the checkbox will always be selectable. In the V7.4.2 release (due out today) the limits for the speedo calibrations values have been reduced to sane values:

H0101: 100..90% of max (pulses per mile)
H0102: 10..50 (teeth on speedo pickup)
H0103: 1..5 (diff ratio)
H0104: 500..5000 trans output shaft revs per mile

Regards
Paul

[2002_z28_six_speed]

There may be some potential problems with making the option not an option any more like for those who are using a Corvette PCM, dash & powertrain in another vehicle or those who swap in a solid axle to the C5. Maybe a nice, big, flashing warning box could pop up instead? Just trying to think ahead...

I like your thinking. Its super easy to have a Corvette like setup with a rear mounted TH400. hmmmmmmmmmmm

[Boost]

Just an update, I have since tuned an LS2 with the new version and it worked good. It's not confusing the controller any more, but I am still working on getting the speedometer and odometer to read correct due to the troublesome 4.56 gears.

[S10Wildside]

We just resolved an issue with a 4L60E shifting from 1st through 4th gear in a matter of seconds due to the transaxle box being checked. This Corvette is using a modified 98 Camaro LS1 engine, with the Corvette electronic throttle components and a 4L60E. The calibration is 2002 Corvette.

The shifting problem went away after going through the speedometer calibration and unchecking the transaxle box.

[Boost]

Thanks for the info, and nice project !

[L31Sleeper]

Does a 100% Loop mean that you can not flash in the correct value ??

-Justin

[Blacky]

Does a 100% Loop mean that you can not flash in the correct value ??

-Justin

The "100% loop" refers to the PCM getting an error during start-up (like a divide by zero error), then resetting and starting up again, only to get the error again and restart again.
It stays in that restart-failure-restart-failure loop for ever.
That means the PCM is useless and the only recovery method is to remove the flash chip and reprogram it externally.

Regards
Paul