NefMoto

Technical => Diagnostics => Topic started by: Lowc5Avant on January 02, 2019, 11:48:58 AM



Title: C5 a6 2.8 to 2.7t swap
Post by: Lowc5Avant on January 02, 2019, 11:48:58 AM
Did a swap,  changed ecu out for the 2.7t ecu now trans is stuck in limp mode with code p1841
Tried clearing codes, didnt fix it. ECU is soft coded for the auto trans, and has a bone stock map. Is there anything else I need to do to get the trans out of limp mode?

Any help is appreciated.


Title: Re: C5 a6 2.8 to 2.7t swap
Post by: macxxx on January 02, 2019, 11:57:49 AM
Change the transmission ecu if th ratios are the same , change to automatic trans from 2.7t or swap to manual


Title: Re: C5 a6 2.8 to 2.7t swap
Post by: Lowc5Avant on January 02, 2019, 12:01:54 PM
Can you elaborate slightly on that? The TCM  was good prior to the swap and worked fine so I doubt the swap caused the TCM to go bad, this only became present post swap with the new ECU. manual swap is not in the cards for me at the moment sadly.


Title: Re: C5 a6 2.8 to 2.7t swap
Post by: macxxx on January 02, 2019, 12:03:21 PM
The 2.8 tcm is not compatible with ecu from 2.7t



Title: Re: C5 a6 2.8 to 2.7t swap
Post by: Lowc5Avant on January 02, 2019, 12:06:07 PM
Is there a way around swapping the tcm? Or is that the only way to fix this issue outside of manual swapping or getting a 2.7t auto?


Title: Re: C5 a6 2.8 to 2.7t swap
Post by: macxxx on January 02, 2019, 12:09:47 PM
As i remember ratio is diffrent so uf swap a tcm from 2.7t it will go also in limp mode - we fought with it with my friend and tried diffrent tcm dumps...ut ended with a swap to manual

Maybe you can workaround it modifing tcm dump to adjust ratios but we had no info about maps in it


Title: Re: C5 a6 2.8 to 2.7t swap
Post by: Lowc5Avant on January 02, 2019, 12:12:28 PM
Thanks for the info, I suppose I will attempt to dig deeper into the issue and see what I can come up with.