What to do if you get PPPP displayed on the OBC
I've heard that disconnecting the battery for a long time (like 1 hour) will make this go away.
I lived with this problem for several (3) years. I tried disconnecting the battery for the 1+ hours or so to no avail. The ultimate solution was to disconnect the computer itself from its multi-pin connector. I left it unhooked for approximately 24 hours. Upon reconnecting the computer.....viola a full up and running OBC II.
So here is what works most of the time.
With the key in the "Radio" position (Radio and OBC light up, but not the instrument cluster), press the "CODE" button. Then push the little reset-hole with a Pen and hold it, 'till the computer blinks in the display, and it will ask you for a time and date entry. - You now have re-adapted the coding plug to the computer. - Normally the computer goes into a PPPP mode when the car has been boosted, or some other very drastically voltage changes have occurred