Electrical Platforms TL;DR

Brief explanation of electrical platforms in VAGs small car lineup

PQ25

It's similar on a network level to PQ35 vehicles however it has an integrated CAN BUS Gateway, this means harnesses like J533 will not work.

PQ26

This platform is the successor to PQ25, this platform speaks both in MQB and PQ's CAN BUS messages, the extent of which hasn't been explored, the most important thing to know is the EPS should be running MQB firmware. This also has an integrated CAN BUS gateway, therefore J533 harnesses will not work.

MQB-A0

This platform is the successor to PQ26, this platform does not have the interoperability as seen in PQ26. This has a dedicated CAN BUS gateway, therefore J533 harnesses will work.​

Platform	J533 Harness	PQ Messaging	MQB Messaging
PQ25	NO	YES	NO
PQ26	NO	YES	YES
MQB-A0	YES	NO	YES