Complex Problem
Thread Starter
Teching In
Joined: Jul 2008
Posts: 28
Likes: 0
Complex Problem Hi Guys ,
Need your help. Ok here is a rundown of the problem :
We built a 2008 GMC Sierra 1500 with the following mods :
418 L92 , D1SC @ 14 PSI , 4L80E Swap controlled via a TCI standalone Trans Computer . The swap involved us having to custom cut the driveshaft on the vehicle . The new one isn't perfect but does the job. Side Effect is that it does vibrate at high rpms. Another side effect is the we had the factory TCM unconnected . The same caused the following ECM/TCM Errors :
ECM U0102 ( Cancelled this via Hp Tuners )
ECM U0109 ( Cancelled this via Hp Tuners )
TCM P0787
TCM P0961
TCM P0973
TCM P2764
TCM P2769
The first two we cancelled the rest we couldn't. What happens is this , when we gradually increase throttle input Timing drops down to very low levels ( 4 degrees in the latest scan ) while KR gradually climbs ( 7.4 degrees in latest scan ) . Our theories behind the same :
1- The TCM DTCs are causing the drastic pull in timing ?
2- The makeshift driveshaft is causing vibration severe enough to fool the knock sensors into pulling so much timing ?
For reference WOT AFR is @ 11.1 ( we are still fine tuning it , so keeping it at this level to ensure safety and no Knock )
Need your help. Ok here is a rundown of the problem :
We built a 2008 GMC Sierra 1500 with the following mods :
418 L92 , D1SC @ 14 PSI , 4L80E Swap controlled via a TCI standalone Trans Computer . The swap involved us having to custom cut the driveshaft on the vehicle . The new one isn't perfect but does the job. Side Effect is that it does vibrate at high rpms. Another side effect is the we had the factory TCM unconnected . The same caused the following ECM/TCM Errors :
ECM U0102 ( Cancelled this via Hp Tuners )
ECM U0109 ( Cancelled this via Hp Tuners )
TCM P0787
TCM P0961
TCM P0973
TCM P2764
TCM P2769
The first two we cancelled the rest we couldn't. What happens is this , when we gradually increase throttle input Timing drops down to very low levels ( 4 degrees in the latest scan ) while KR gradually climbs ( 7.4 degrees in latest scan ) . Our theories behind the same :
1- The TCM DTCs are causing the drastic pull in timing ?
2- The makeshift driveshaft is causing vibration severe enough to fool the knock sensors into pulling so much timing ?
For reference WOT AFR is @ 11.1 ( we are still fine tuning it , so keeping it at this level to ensure safety and no Knock )
Hi Guys ,
Need your help. Ok here is a rundown of the problem :
We built a 2008 GMC Sierra 1500 with the following mods :
418 L92 , D1SC @ 14 PSI , 4L80E Swap controlled via a TCI standalone Trans Computer . The swap involved us having to custom cut the driveshaft on the vehicle . The new one isn't perfect but does the job. Side Effect is that it does vibrate at high rpms. Another side effect is the we had the factory TCM unconnected . The same caused the following ECM/TCM Errors :
ECM U0102 ( Cancelled this via Hp Tuners )
ECM U0109 ( Cancelled this via Hp Tuners )
TCM P0787
TCM P0961
TCM P0973
TCM P2764
TCM P2769
The first two we cancelled the rest we couldn't. What happens is this , when we gradually increase throttle input Timing drops down to very low levels ( 4 degrees in the latest scan ) while KR gradually climbs ( 7.4 degrees in latest scan ) . Our theories behind the same :
1- The TCM DTCs are causing the drastic pull in timing ?
2- The makeshift driveshaft is causing vibration severe enough to fool the knock sensors into pulling so much timing ?
For reference WOT AFR is @ 11.1 ( we are still fine tuning it , so keeping it at this level to ensure safety and no Knock )
Need your help. Ok here is a rundown of the problem :
We built a 2008 GMC Sierra 1500 with the following mods :
418 L92 , D1SC @ 14 PSI , 4L80E Swap controlled via a TCI standalone Trans Computer . The swap involved us having to custom cut the driveshaft on the vehicle . The new one isn't perfect but does the job. Side Effect is that it does vibrate at high rpms. Another side effect is the we had the factory TCM unconnected . The same caused the following ECM/TCM Errors :
ECM U0102 ( Cancelled this via Hp Tuners )
ECM U0109 ( Cancelled this via Hp Tuners )
TCM P0787
TCM P0961
TCM P0973
TCM P2764
TCM P2769
The first two we cancelled the rest we couldn't. What happens is this , when we gradually increase throttle input Timing drops down to very low levels ( 4 degrees in the latest scan ) while KR gradually climbs ( 7.4 degrees in latest scan ) . Our theories behind the same :
1- The TCM DTCs are causing the drastic pull in timing ?
2- The makeshift driveshaft is causing vibration severe enough to fool the knock sensors into pulling so much timing ?
For reference WOT AFR is @ 11.1 ( we are still fine tuning it , so keeping it at this level to ensure safety and no Knock )
Thread Starter
Teching In
Joined: Jul 2008
Posts: 28
Likes: 0
End result would have still been the same correct ? See the requirement was have the transmission shift automatically which was achieved via the TCI unit. Even the GM Controller won't interface with the newer GM Lan correct ? That is our problem. The newer GM Lan doesn't work with the older style 4L80E which we have in the Truck at the moment. 
