I took it to get it smog did not pass smog they said that computer did not communicate whit the car computer they said to check wire # 16

It won't pass smog in California because the 1st thing a smog tech does it check for fault codes on the vehicle's computer with a scanner.

Check for loose pins or backed out pins in the OBD diagnostic port.

Disconnecting the battery resets the PCM - engine computer ,an the emission monitors . A drive cycle has to be done to get the monitors to run an hopefully set. That's all you need to do is drive it for few days of different driving conditions - city , highway ,from cold start . google GM drive cycle . OBD Monitor Not Ready

Probably something in the wiring harness or the engine computer.
A mechanic would watch the data stream from the O2 sensors to troubleshoot. You should also have trouble codes for the sensor in question.

Auto zone will scan it for free, will print out the code, wait the emissions paper will tell you the codes at fault, autozzone will double check for ya.

There should be a 10amp fuse in the fuse box for the instrument panel that powers the light. The light is grounded by the computer.
Have you checked the fuses in the passenger compartment ?

Codes do not tell you what to replace.
The cam sensor most likely was okey

PO302--as you said, is a misfire on cylinder #2,work on that problem
Spark plug wire,bad coil pack,etc.

Seek professional help,it will be quicker,cheaper in the long run, and they can verify it will pass inspection.

OBD Codes and check lights,only indicate a possible system malfunction
Then you need the knowledge, to diagnose the system ,and find the cause of the MIL Lamp being on

No this is not right. If you remove the battery everything resets anyways. If they are talking about relearn procedure, it should only require 50 miles. But if the light is on than either they did something wrong, created another problem, or there was already another one existing. Have the code read and let me know what it is. I'm in Ca too and used to prep european cars for smog, so I do know what I'm looking for. How did the rest do? What were the readings(if possible)?

the no data error can be contributed to a bad interface cable or the scaqn tool was configured wrong and therfore could not connect to the ecm. I would recommend having a scan done again by a certiefied volkswagon tech chances are the mechanics used the wrong adapter cable or reader card. your smog problem could be that your evap canister is clogged therfore gives a bad reading.unfortunately you have to have a scan done but try an independant small shop that delas exclusively with foreign cars such as porche andd mercedez. the will have the correct scan tool and will be much cheaper than a dealership. your cost should be no more than 50 dollars US ... please rate this. thanks

Not a solution: This is my problem...
I needed to get my car smogged, but the check engine light was on. Took to to a local smog station that had replaced a sensor for me in the past in order to pass smog. They could not fix it. Put car in dealership garage for repairs and to date, the transmission module sensor (computer) went out and the ignition sensor was out also. The mechanic replaced both and now the code P1702 comes up. What does that code mean? My car still won't pass smog....