I've got an Escalade EXT that was duramax swapped(2006 EXT and 2007 Silverado LBZ) and I'm having some module communication issues. The previous owner did a great job on the swap with everything mechanical but a lot of the electrical still doesn't work. All the wiring and the cluster are from the Silverado that the engine came from.
The biggest issue I'm having is the shifter position (PRND) is not displaying on the cluster, causing the reverse lights to not turn on when in reverse and not able to enter 4Low. From what I've read I think I have some kind of issue related to the low speed data bus.
I have a VXDIAG scan tool with Tech2Win and it seems I can only communicate with the high speed bus. Everything looks fine as far as they go with it recognizing both the PRND position and transmission temp properly in Tech2Win, and the truck starts and shifts properly so obviously the ECM and TCM are communicating with each other properly. The reverse lights come on then I lock/unlock the truck with the fob so they work as well. However, it reads no communication with the BCM, TCCM, or Chassis control module. The cluster does not show the trans temp either(stays at 0).
I looked at connector diagrams for the OBD2 port and everything seems to be wired correctly there. I also looked at the connector diagram for the Instrument Cluster and there's a green wire that's supposed to be for the PRND position. It read 0 volts so I'm thinking that could possibly be my problem.
Does anyone know where that wire goes(I'm assuming the TCM or the transmission harness itself) or what it's supposed to read for voltage? If anyone can help with that or has any other Ideas it would be greatly appreciated.
Thanks
The biggest issue I'm having is the shifter position (PRND) is not displaying on the cluster, causing the reverse lights to not turn on when in reverse and not able to enter 4Low. From what I've read I think I have some kind of issue related to the low speed data bus.
I have a VXDIAG scan tool with Tech2Win and it seems I can only communicate with the high speed bus. Everything looks fine as far as they go with it recognizing both the PRND position and transmission temp properly in Tech2Win, and the truck starts and shifts properly so obviously the ECM and TCM are communicating with each other properly. The reverse lights come on then I lock/unlock the truck with the fob so they work as well. However, it reads no communication with the BCM, TCCM, or Chassis control module. The cluster does not show the trans temp either(stays at 0).
I looked at connector diagrams for the OBD2 port and everything seems to be wired correctly there. I also looked at the connector diagram for the Instrument Cluster and there's a green wire that's supposed to be for the PRND position. It read 0 volts so I'm thinking that could possibly be my problem.
Does anyone know where that wire goes(I'm assuming the TCM or the transmission harness itself) or what it's supposed to read for voltage? If anyone can help with that or has any other Ideas it would be greatly appreciated.
Thanks