Understanding the system and symptoms
Modern Audi vehicles use multiple networked control modules. Low supply voltage, corroded connections, incorrect coding, module failure and bus communication faults can create overlapping warnings. A module listed in a scan report is not necessarily the failed component.
How a technician narrows down the cause
Record battery state of charge and charging voltage; perform a complete module scan before clearing codes. Separate active faults from historic low-voltage events, inspect power and ground at the affected module under load, and evaluate communication lines using the vehicle wiring diagram. For collision or water exposure, inspect connectors and harness routing before replacing modules.
Model-specific context: Audi A6; researched applications 2012–2014; platform A6 C7. Exact applicability should be checked against the vehicle identification number and equipment.
What owners may notice in researched cases
- Passenger-side cooling fan runs at high speed with key on and the check-engine light is illuminated
- Engine cooling fan continues running after the vehicle is switched off
- Right headlamp and daytime running lamp inoperative
Diagnostic observations from the source cases
The available technical cases describe checks such as Command Fan 1 with scan tool and test its supply; Inspect Fan 1 circuit protection; Command intercooler coolant pump V188; Test power and ground at V188. These checks help distinguish competing causes before recommending replacement.
Possible causes identified in individual cases
The underlying causes documented in individual cases included Blown Fan 1 supply fuse and failed intercooler coolant pump V188; Internally shorted J671 coolant-fan control module. These are examples of verified findings in those cases, not a prediction of what has failed on every Audi A6.
Repairs reported in the source cases
Repairs reported to resolve documented cases included Replace intercooler coolant pump V188 and clear codes; Replace J671 control module/fan assembly. A repair that succeeded on one vehicle should only be recommended for another after confirming the same fault.
Why confirmation matters
Why diagnosis matters: The research also recorded unsuccessful or temporary repair attempts, including Replace both headlamp modules and right bulb — unsuccessful. This illustrates why replacing a commonly suspected part without testing can waste time and money.
Fault codes recorded in the research
Codes mentioned in the research: P0691, P190D, P0481, 02897, 00979, 00927, P069100, P0693, P069300, P1B1C. Codes can have different interpretations depending on model and conditions.
Verification and next steps
After repair, verify communication with all affected modules, complete any required coding or basic settings, and check that warnings remain absent over repeated key cycles.
If your Audi A6 is showing these symptoms, Mich’s Foreign Cars in Hickory, NC can discuss an appropriate diagnostic appointment. Call 828-324-6012 and provide the year, engine, warning messages and any available fault codes.