My 02 VW Jetta,car wont start and only battery light appears,and before 5 or 6 lights would come on when i tried to start it,now they dont,and what causes this,seems its lost the power to bring the other lights up,and it tries to start but cuts off after 3-seconds,all the fuses check out good,so need to know why lights wont come on and why it wont start-thank you,hope you have some ideas

SOURCE: 02 VW engine light that stays on

You probably need to replace the glow plug harness. The contacts in the boots that connect to the glow plugs get corroded and throw off the resistance of the circuit. The controller in the VW measures whether your glow plugs are good or not by testing the resistance in the circuit. Test all the glow plugs like DickyIV1 stated and if they are all good try cleaning out the crud on the contacts in the glow plug harness. You will then either need to clear the error code or wait several trips for it to clear itself. If it never clears itself or if it comes back on after you clear it then the glow plug harness is too much of a mess. This is really common on the TDIs (mine needs to be changed but i have been putting it off and ignoring the mil light). When I first tried cleaning the harness on my car it didn't give me a problem for another year and a half. But I knew I'd eventually be changing it.
The other thing to keep in mind is that you should change out glow plugs as a set. It causes less problems in the long run since if one failed you will probably find other will soon fail and it keeps all the resistance close to the same value.

SOURCE: 1999 VW jetta TDI

p1248 is in the same error codes as the rest now i have been a mechanic for plenty of years and i will tell you it will be the glow plugs they have a certin limit to glow to start the car if they are worn or nearly gone they wont hold all the fire in them ,,,,Injection start control deviation means the car is not getting even to kick start it it maitanes and shuts the engine down if there is a problem i suggest you changed the plugs and see how you go here is a link to see http://www.patentstorm.us/patents/5778852/description.html

SOURCE: Oil light flashing & beeping

This usually indicates that the oil pressure is low, but you need to get it checked out whether it's just a pressure sensor fault or connection issue, or it actually has got low oil pressure. The last one is the most concerning, because it could be causing internal damage if there is not enough oil pressure. Hopefully with a relatively late model car it will just be a sensor issue, but I would get it checked out ASAP, and preferably not use the car in the meantime.
Hope this helps, Mark.

SOURCE: electronic immobilizer

most likely cause is the gauge cluster, this will have to be tested and service by your local dealership because the dash cluster and keys have to be coded. I have seen the immobilizer loose it's coding for apearantly no reason. therefore have them recode cluster and see if problem goes away, if it doesn't the gauge cluster will have to be replaced.

SOURCE: 02 VW GTI Radio says CHECK

This worked for me (radio in 2003 VW Golf):
Radio says "CHECK" but is otherwise unresponsive. Turning car or radio on/off doesn't help.
On the far right of the radio, there's a round TUNER button. Press it for 5 seconds. Your screen will then show some digits, but the unit is still unresponsive.
Press tuner button again for 5 seconds. Radio should now be 100% again. Let me know if this works for you.