We had a LLY come in the shop with a intermittent issue, went through diag and came to conclusion TCM needed to be replaced. Got replacement from dealer took it to be programmed and they said it wont communicate, they warrantied it out got another same thing. When new TCM is plugged in they cant communicate with ECM or TCM. But with old one plugged in it works great until the intermittent issue pops up and will communicate with everything! Any ideas? TIA
LLY new TCM won't communicate after TCM replacement
- Thread starter LBZ_Baker98
- Start date
Yes, i can communicate with everything when the original TCM is installed, when the new "blank" TCM from GM is installed I cant communicate with ECM or TCM.
I would double check power and ground to both the TCM and ECM. You can also try bench flashing the TCM
Sadly you may have to bench flash the unit as mentioned.
My LLY Truck reads and flashes the TCM through the OBD port just fine. However my friend's LLY has an issue with Noise on the communication bus. I can read it but I can not flash the TCM.
Both trucks are stock with no aftermarket components installed. He did have an issue with his ground to the TCM and he had to run a new wire. But according to the logs something is active on the communication bus.
My LLY Truck reads and flashes the TCM through the OBD port just fine. However my friend's LLY has an issue with Noise on the communication bus. I can read it but I can not flash the TCM.
Both trucks are stock with no aftermarket components installed. He did have an issue with his ground to the TCM and he had to run a new wire. But according to the logs something is active on the communication bus.