mothertruckercustoms Posted June 20 Share Posted June 20 (edited) Barra/zf6 in a patrol. Seems to drive ok, but what i notice is when i scan with forscan the TCM/OBD speed reads about 20% low, and the PCM speed reads about 10% high. I have tried modifying the diff ratio and rev per mile settings in VID and these seem to change nothing. I played around with the tyre size figure in VID and what i noticed is when i lower it i can make the speedo more incorrect in PCM only, but when i raise it to try and correct it nothing changes. How do i get these values correct? I know from my LS experience that the 6l80 trans needs to read speed correctly otherwise they dont drive very well, i assume the zf6 would be the same? Or am i wasting my time here on a non problem. FG2 ecu/tcm that was flashed to FG1 and return to stock file made/flashed Edited June 20 by mothertruckercustoms Quote Link to comment Share on other sites More sharing options...
Roland@pcmtec Posted July 2 Share Posted July 2 Change the axle ratio in the VID block if the VID block is enabled, if its not enabled use the VID block PCM overrides. If you have a ZF also change the ZF diff ratio in ZF03985 (there are two values in case you had AWD). There is also a correction factor here which should not need to be changed but can be in some circumstances. ID Name Value ZF00132 correct wheel speed diference 0.150024 ZF04252 Correction factor wheel circumference, ratio of differential 1 Quote Link to comment Share on other sites More sharing options...
mothertruckercustoms Posted July 3 Author Share Posted July 3 I notice if i go above a certain value it shows a red diamond nexto it, is this a problem? Quote Link to comment Share on other sites More sharing options...
mothertruckercustoms Posted July 6 Author Share Posted July 6 i played around a little more with this, increasing the maximums i was about to get the speed right via pcm the tcm i had already changed the diff ratio to 3.9, the other two values are not present, namely ID Name Value ZF00132 correct wheel speed diference 0.150024 ZF04252 Correction factor wheel circumference, ratio of differential 1 I have pro edition, are these workshop edition only or something? I can get the ZF reading right speed by fudging the diff ratio until its right, would this be adequate without access to the other values? Does it even affect how the zf behaves? Quote Link to comment Share on other sites More sharing options...
Mick Posted August 6 Share Posted August 6 Did you have any luck getting this sorted? FG MK2 is different to the earlier ones and does not respond to the same changes Quote Link to comment Share on other sites More sharing options...
mothertruckercustoms Posted August 6 Author Share Posted August 6 Hey mate, yes i did by changing parameters as directed, however some options were not available, perhaps because i have pro, not workshop. But still got it sorted 1 Quote Link to comment Share on other sites More sharing options...
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