The car had been in the garage for few days when this afternoon I started the engine and got engine light.
I ran the reader and got these message :
18032.P1624 Mil request signal : active
18228.P1820 Pressure control valve 2-N216 : short to B+
18233.P1825 Pressure control valve 3-N217 : short to B+
no clue what is going on, car is running fine (I guess, hopefully the error will not come back)
So I cleared the error but curious to know what went wrong.
The garage temperature was around 40-50F, if some one can assist me for further action needed or explain what might be wrong, I do appreciate it
I brught the car to local Audi mechanic who suggested some weak solenoid or problem with the harness may caus the problem.
I also notice that it happened only in the morning when I started the engine and get that failsafe mode and sometime check engine light. Then a good friend of mine who also mechanic from other car suggested to check the batteries. Yup, the culprit is the battery, when I started it dropped to below 9 V, so I decided to get new battery and seems it resolve the problem.
No backup mode and no error, in fact (not sure is this just me) it runs better, the transmission works smoother.
Audi circuitry is sensitive, replace the battery if it is more than 5 years, mine was 6 1/2 years.
Hi there, good that the fault codes does not returned back, lucky you, but, insufficient battery voltage would cause all kind of problems and codes but not those related with the transmission valve body solenoids.
I had the same problem during the two last years dur to a BAD BATTERY.
Frist I think was ATF oil, it only hapend whith cool wheather.
Finally I change the battery I the problem seams gone for ever!!!!!
Thanks a lot for all the people who share their opinion in the foruns.