Help with code P1720

[Cisc0]

Cruising my X shuts off on me and "Trans Fail Safe" kicks in along with all the christmas lights on the cluster. I park and turn off. Wait a few mins and try to turn back on, after is on all seems fine, I drive a block and boom same sh*t. Pull out the code reader and the code I get is: P1720. Did a search on here but to no avail. Did a google search and came up with this:

Local CAN bus

The CAN bus (Controller Area Network) is a serial bus system, in which all connected stations are equally entitled, i.e. each control unit can both send as well as receive. In other words, the connected control units can "communicate" and exchange information via the lines.

Due to the linear structure of the network, the bus system is fully available for all other stations in the event of one station failing. The connection consists of two data lines (LOCAN_L and LOCAN_H).

The local CAN bus exists independently of the familiar CAN bus. The local CAN bus serves only engine functions. The data exchange across the Local CAN bus takes place between the following control units, depending on the engine variant:

DME control unit

Valvetronic control unit

HDEV control unit

The connected control units must all have the same CAN status. The CAN status can be checked via the diagnosis interface. The CAN status (bus index) is specified on the identification of the relevant control unit connected to the CAN bus


I'm guessing one of the three Control Units above failed to boot up properly.

A lil more info to try a narrow down. About a less than a month ago I had my DME replaced with a used one and coded to my vehicle due to an electrical shortage caused by a screw in my A/C's wire harness. Can this possibly be a lead to what the culprit is? Can someone who's encounter said code shed some information on your experience please.

I will be taking the X back to the shop that performed the coding on the DME first thing in the morning.

Thanks in advance for any replies.