One problem related to wiring has been reported for the 2003 Audi A6. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Audi A6 based on all problems reported for the 2003 A6.
Brake light switch failure. Had it fixed, but the problems seems to be not in the brake light switch itself, but the wiring or sockets to the switch. Used same switch, but soon as car is turned off and turned back on, switch tends to work only for a couple of days and abs system shows up again with no brakes lights at all. Took to Audi dealer in which they said that there has been many problems within this system. But to totally fix the problem would run anywhere from 700. 00 to 1200 dollars on a 35. 00 to 45. 00 part. No brakes could lead to serious accidents not knowing that your brakes lights are actually out. Please please recall this issue on all Audi's.