Different letters in tax equipment numbers

Hello,

I have a general question about Bosch engine control units for TDI engines from the VW/Audi group. Neither the forum search nor the Bosch online catalog provide any information on this. And that, in particular, refers to the last character in the part number.
z.B.

4A0 907 401 E
4A0 907 401 P

What does the last digit of the number represent, or what does it indicate? According to the Bosch online catalog, these numbers represent different control units. Therefore, the control units must not be identical. Could it be the software version?

Best regards,
huskydoctor

HI

There are all possible combinations of letters between the 3x3 digits.

Generally, it states that there are different versions - of course, another number (and the last letter belongs to the number, different part)

What exactly is different, is, if it is described somewhere else.

Regarding the G3 TDI, the 028 906 021 GG part was originally installed as a single unit in the AHU (Air Handling Unit), and also replaced the ..AF part from the 1Z engine. However, if it is installed as a replacement part, it will be coded differently. So, it can also control "more" than just the AF, namely a 1Z and an AHU.

If your information states that one part replaces another, it is possible that it is also so....

m;