This was posted on the bmw coding forum and also reposted several times here:
Basically read your NFRM/FRM. Then take the NETTODAT file and make a copy to compare from.
Now change the AE wert_06 or whatever it is and change it to wert_01 and recode the car.
Now read the module again and compare this NETTODAT file to the last.
You'll find 2 bytes (values) that changed.
Then you change them:
00 10 --> [0,0V]
55 05 --> [5,95V]
DD 05 --> [6,6V]
21 06 --> [6,9V]
10 09 --> [10,2V]
F4 09 --> [11,2V]
D7 0A --> [12,2V]
49 0B --> [12,7V]
8D 0B --> [13,0V]
BB 0B --> [13,2V]
FF 0B --> [13,5V]
2C 0C --> [13,7V]
38 0E --> [16,0V]
Save this NETTODAT and recode using the NETTODAT instead of the normal MAN file.
Once you get over the battery voltage - the pwm is effectively disabled.