There are 9 owner-reported electrical system complaints for the 2005 Audi A6in NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
START ACCESS CONTROL UNIT (J518) MALFUNCTION. CAR WILL NOT START. AUDI DEALER CLAIMS THAT WHOLE STEERING COLUMN MUST BE REPLACED. QUOTE $2,400.
VERY COMMON PROBLEM - "IGNITION MODULE DEFECTIVE" CODE AT 190,000 MILES. TEMPORARY REPAIR OF THE ISSUE WITH DTC RESET. FULL LOGGING OF CAR DATA VIA OBD-II PORT REVEALS ZERO FAULTS WHILE CAR IS RUNNING, AND DIAGNOSTIC TRAFFIC ON THE CAN BUS AT STARTUP SHOW ZERO FAULTS. ONCE KEY IS INSERTED IN DASH AND TURNED TO "ACCESSORY", MODULE FAULTS OUT WITHOUT ANY TRAFFIC SENT/RECEIVED. HAPPENS INTERMITTENTLY AND DEALERSHIP STATES THIS IS A KNOWN PROBLEM. DEALERSHIP-ONLY REPAIR, PER MULTIPLE AUDI SERVICE TECHNICIANS, AUDI OF AMERICA REFUSES TO COMPLY WITH MASSACHUSETTS RIGHT TO REPAIR LAW BY MAKING AVAILABLE TO INDEPENDENT REPAIR SHOPS, THE NECESSARY TOOLS AND EQUIPMENT TO ACCESS THE IMMOBILIZER HARDWARE. DEALER ESTIMATES/QUOTES RANGE FROM $2100-$3700 TO REPLACE ENTIRE STEERING COLUMN WITH THE ATTACHED AND SEPARABLE IGNITION MODULE (ACCESSIBLE VIA 2 SCREWS AND 1 RIVET). DEALERSHIPS REFUSE TO REPLACE/RE-CODE ONLY THE IGNITION MODULE, STATING THE ENTIRE STEERING COLUMN NEEDS REPLACED. MULTIPLE REPORTS OF THE SAME ISSUE WITH OTHER C6 BODY AUDI A6 OWNERS CONFIRM THE SAME DETAILS. NOTHING IS PHYSICALLY WRONG WITH THE IGNITION SWITCH OR MODULE, AND CLEARING DIAGNOSTIC TROUBLE CODES ALLOW THE VEHICLE TO START IMMEDIATELY. SUSPECT PLANNED OBSOLESCENCE OF THE PART IN QUESTION.
MY CAR WAS RUNNING PERFECTLY, NEXT TIME I WENT TO DRIVE IT, IT WOULDN'T START. THE WHEELS AND SHIFTER ARE LOCKED UP .THE LIGHTS AND BELLS WORK, BUT IT TURNS OUT THAT THE MODULE THAT RECOGNIZES THE KEY HAS FAILED. I HAVE BEEN ON JUST ABOUT EVERY AUDI FORUM TO INVESTIGATE THIS, AND THIS IS AN INCREDIBLY COMMON COMPLAINT. THE PART THAT IS BROKE CANNOT BE FIXED, RATHER THE ENTIRE STEERING COLUMN HAS TO BE REPLACED AT A COST OF AT LEAST $2000, IN SOME CASES OVER $3000. THIS IS AN OBVIOUS DESIGN DEFECT AND AUDI NEEDS TO BE HELD RESPONSIBLE. PAYING THOUSANDS OF DOLLARS FOR A MODULE THAT FAILS TO RECOGNIZE A KEY IS BEYOND RIDICULOUS. THERE WERE NO WARNING LIGHTS WHATSOEVER TO INDICATE THAT THIS PART WAS FAILING. LUCKILY IT IS CURRENTLY STUCK IN MY DRIVEWAY. IT COULD HAVE LEFT ME STRANDED ANYWHERE.
THE LEFT DRIVERS SIDE BREAK LIGHT/SIGNAL WILL STOP WORKING INTERMITTENTLY. I HAVE NOTICED THAT IT TENDS WEATHER DEPENDENT. I HAVE READ AUDI FORUMS WHOM HAVE SAID THAT THE ELECTRICAL WIRING WHEN EXPOSED TO HEAT (70 DEGREES FAHRENHEIT AND ABOVE) WILL SHORT CAUSING THE LED BREAK/SIGNAL LIGHT TO NOT WORK. MY MECHANIC STATED THAT IT IS ALSO BECAUSE OF A FAULTY "LIGHT CONTROL MODULE + WIRING." DUE TO THE INTERMITTENCY AND HIGH COST OF THE JOB IT HAS NOT BEEN SOMETHING THAT I HAVE BEEN ABLE TO FIX. I AM AFRAID THAT EVENTUALLY NONE OF THE TAIL LIGHTS WILL WORK OR EVEN AFTER REPAIRING IT, THE SAME ISSUE WILL ARISE. I FIRST NOTICED THIS IN MAY OF 2015, HOWEVER IT WAS FINE THROUGH THE FALL AND WINTER. I AGAIN NOTICED IT RANDOMLY THROUGH THE SUMMER MONTHS (JUNE-AUG).
WE HAVE A 2005 AUDI A6 PURCHASED CPO IN 06. WE RECENTLY HAD ISSUES WITH BRAKE MODULE ISSUES THAT ARE STILL THERE BUT WAITING ON THE RECALL FOR THIS ISSUE. NOW WE HAVE AN ISSUE WITH OUR MMI SYSTEM WHICH IS THE ENTERTAINMENT PART OF THE CAR. IT CONTROLS THE MUSIC, NAVIGATION, AND SOME CONVENIENCE FEATURES. I HAVE SEEN A LOT OF AUDI OWNERS WITH THIS MMI PROBLEM AS WELL. THERE SEEMS TO BE A TREND WITH AUDI VEHICLES NOW. I WOULD THINK WHEN YOU MAKE A LUXURY PURCHASE SUCH AS THIS YOU WOULD NOT HAVE THESE KINDS OF ISSUES. CERTAINLY IF YOU ARE NOT ABUSING THE CAR IN ANY WAY. THIS ALSO NEEDS TO BE A PART OF A RECALL. THE FIRST INDICATION WAS I COULD NOT RESET THE BATTERY AFTER THE REPLACEMENT WHICH WAS NOT DONE BY AUDI. THEN I TOOK IT TO THEM TO RESET THE BATTERY LEVEL AND RECODE THE MMI AND AUDI COULD NOT DO IT? THERE IS AN ISSUE HERE.... *TR
AUDI 2005 A6 STARTED TO HAVE INTERMITTENT WARNING FOR ABS, STABILITY, HAND BRAKE AT ~55K MILES. TOOK CAR TO DEALER TO DIAGNOSE IT . DEALER CALLED WITH AN ESTIMATE OF $2800 TO REPLACE ABS MODULE. HE ALSO PROVIDED AN ESTIMATE OF $1100 FOR ANOTHER ERROR CODE FOR AIRBAG TO REPLACE THE CENTER REAR SEAT BELT. I'M NOT UNDERSTANDING WHY THESE WARNING CODES COME SO RANDOMLY AND CLEAR SO RANDOMLY. NOT SURE WHY AN AUDI A6 WILL NEED SUCH REPAIRS THAT CLEARLY POINT TO FLAWS IN DESIGN AND UNRELIABLE PARTS AFTER ONLY 55K MILES. THERE ARE TONS FOR ONLINE COMPLAINTS FROM AUDI DRIVERS THAT USE THE BOSCH 8.0 ABS MODULE. AUDI SHOULD EITHER RECALL THIS PART OR OFFER TO PAY FOR THE REPAIRS. WHEN I COMPLAINED TO AUDI USA, BASICALLY THEY ASKED IF I WAS FIRST OWNER AND IF I TAKE IT TO DEALER FOR MAINTENANCE. THE ANSWERS FOR BOTH IS NO. I'M THE 2ND DRIVER. BOUGHT THE CAR WITH ONLY 20K MILES AND SINCE RELOCATING TO HOUSTON, I TAKE THE CAR TO A LOCAL GARAGE FOR OIL CHANGE. I'M LOOKING FOR SAFECAR.GOV TO RECTIFY THE ISSUE WITH AUDI. AUDI DOESN'T EVEN SELL THE ABS MODULE PART ALONE. YOU WILL HAVE TO BUY THE BRAKE PUMP AS WELL. *TR
IGNITION KEY CANNOT BE REMOVED FROM THE IGNITION. CAR MUST BE LEFT UNLOCKED WITH KEY IN IGNITION, LEADING TO POSSIBLE THEFT AND/OR OPERATION BY CHILDREN OR OTHERS. AUDI SERVICE DEPARTMENT ADVISES THAT CIRCUIT BOARD IS DEFECTIVE AND CHARGES MORE THAN $2500 BUT DOES NOT CARRY PARTS IN STOCK - NALLEY AUDI, ROSWELL, GA. *TR
MY SUNROOF WILL NOT RETRACT..
I PURCHASED A 2005 AUDI A6 3.2 QUATTRO IN AUGUST OF 2008 WITH 37,000 MILES. IN DECEMBER 2008 I TOOK THE CAR TO THE AUDI DEALER IN PASADENA BECAUSE THE LEFT REAR TAILLIGHT, LEFT REAR REVERSING LIGHT, AND LEFT REAR FOG LIGHT WERE SHORTING OUT OFF AND ON. SOMETIMES THEY WOULD WORK, SOMETIMES THEY WOULDN'T. THE DEALER SAID THE CONNECTORS TO THAT LEFT TAIL LAMP ASSEMBLY WERE MELTED AND IT WAS FIXED UNDER WARRANTY. THE FOLLOWING SUMMER, 2009, I TOOK THE CAR BACK TO THE DEALER THIS TIME IN SANTA MONICA, CA FOR THE SAME PROBLEM AND AN OIL CHANGE WHERE ONCE AGAIN THEY SAID THE CONNECTORS TO THE LEFT REAR TAIL LAMP, REVERSING LIGHT, AND FOG LIGHT WERE MELTED. I REFUSED TO PAY AND TOOK CAR TO AN INDEPENDENT SHOP FOR A DIAGNOSIS. THEY SAID THE VEHICLE HAS AN ELECTRICAL SHORT AND COULDN'T FIX IT. A WEEK OR TWO LATER, THE LIGHTS WERE WORKING AGAIN. THAT WAS SUMMER/FALL 2009. BY APRIL 2010, THE LIGHTS STOPPED WORKING AGAIN. I TOOK THE CAR INTO ANOTHER AUDI DEALER THIS TIME IN DOWNTOWN, LA. THEY DIAGNOSED THE PROBLEM SAYING THE ELECTRICAL SYSTEM IS SENDING TOO MUCH ELECTRICAL CURRENT TO THAT SIDE OF THE CAR AND IS CAUSING THE WIRING TO BURN AT THE CONNECTION POINT TO THE TAIL LAMP ASSEMBLY. I REFUSE TO PAY FOR SERVICE THAT WAS ALREADY REPAIRED I SAID JUST 15 MONTHS AGO AND ASKED WHY THIS IS ONLY HAPPENING TO THAT SIDE OF THE VEHICLE. THEY TOLD ME I WOULD HAVE TO PAY 385.00 TO FIX IT. I THEN TOOK THE CAR TO ANOTHER INDEPENDENT SHOP THIS WEEK AND THEY REFUSED TO FIX THE CAR BECAUSE THERE ARE BURN POINTS IN THE TRUNK WHERE THE WIRING IS FAULTY AND THAT AUDI SHOULD FIX THE ELECTRICAL SYSTEM IN THE VEHICLE AS IT WILL JUST KEEP HAPPENING OVER AND OVER AGAIN. I'VE ALSO HAD PROBLEMS WITH THE WINDOW SWITCHES NOT WORKING ON THE LEFT SIDE OF THE VEHICLE, AND THE LIGHTS SHORTING OUT IN THE CENTER CONSOLE. THIS IS NOT ONLY A BIG NUISANCE BUT I AM WORRIED THAT THIS COULD CATCH FIRE. PLEASE HELP IN THIS SITUATION, THANK YOU SO MUCH FOR YOUR TIME. *TR
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 26, 2026