2025 Audi Q5/SQ5 Headlight Defective Warning TSB 2078609/5
Owners of 2025 Audi Q5 and SQ5 vehicles may see a "Left/right main beam headlight defective" warning message and DTC C12FC01. This TSB addresses the software issue causing the warning.
Gilt auch für
- Audi SQ5
- 2025
Owners of certain 2025 Audi Q5 and SQ5 models may encounter a dashboard warning message stating, "Left/right main beam headlight defective. See owner's manual." This issue, which can trigger the DTC C12FC01, indicates a software-related problem rather than a physical malfunction of the headlights. Audi has released Technical Service Bulletin (TSB) 2078609/5 to provide guidance for technicians on how to resolve this specific concern.
This TSB, released on February 19, 2026, and last revised on December 13, 2025 (Revision 4), clarifies that the warning is due to a software anomaly. It also supersedes a previous bulletin, PSS 2078182, which covered the same warning lamp issue in the instrument cluster. The primary solution involves a software update to the vehicle's control modules.
Symptoms
If your 2025 Audi Q5 headlight defective warning appears, you will typically observe the yellow warning message "Left/right main beam headlight defective. See owner's manual" displayed in the instrument cluster while driving. While this warning is active, there are no functional restrictions or performance limitations with the main beam headlights themselves. The warning lamp may disappear after switching the ignition off and then on again, but it often reappears intermittently during subsequent drives.
Fault Codes / DTCs
When diagnosing this issue, technicians will likely find Diagnostic Trouble Code (DTC) C12FC01 stored in the vehicle's diagnostic system. This specific code is identified as "LED channel 4, electrical fault" with symptom code 139272. The fault is typically found in diagnostic address 0029, which corresponds to the Left light control unit, and/or diagnostic address 0039, which corresponds to the Right light control unit. Despite the
Weitere Revisionen dieses TSB
What Audi Q5 owners report
Counted from the records in our database across 18 model years.
- 1,386
- Owner complaints
- 35
- Recalls
- 4,663
- Service bulletins
- 68
- Crashes reported
- 13
- Fires reported
- 63
- Injuries reported
The 2025 model year
46 complaints, the 12th most of 18 model years on file. Owners reported 3 crashes, 0 fires and 3 injuries for this year, which also has 1 recall on file.
Electrical System, the system this article covers, accounts for 230 of 1,386 complaints (17%), including 21 for 2025.
Complaints by model year
| 2010 | 100 | |
|---|---|---|
| 2011 | 143 | |
| 2012 | 168 | |
| 2013 | 92 | |
| 2014 | 106 | |
| 2015 | 100 | |
| 2016 | 78 | |
| 2018 | 209 | |
| 2021 | 74 | |
| 2025 | 46 |
Most-reported systems
- Engine — 338
- Air Bags — 259
- Electrical System — 230
- Fuel/Propulsion System — 140
- Steering — 99
Latest recalls for the 2025 model year
- 26V266000 — Seat Belts (Apr 2026)
Recent owner reports about electrical system
The NEW vehicle keeps showing a warning light on the dash saying that the rear wheel bolts are loose two accidents have occurred in a 60 day period, the vehicle has been in for service multiple times and Audi has not found a fix for the safety light warning…
Read owner complaints →The 2025 Audi Q5 has a systemic problem with its Multi Meidia and driver assist features, such as cruise control, side mirrors, back up camera, directional maps, etc, which malfunction at inopportune times causing major distraction while driving.
Complaints are owner reports filed with NHTSA. They are unverified, and counts depend on how many vehicles were sold, so they are not a failure rate.
Related Articles
2025 Audi Q5 Health Check: TSBs and Software Updates
Explore common issues for the 2025 Audi Q5, including electrical system warnings, door malfunctions, and headlight defects, as detailed in manufacturer service bulletins. Learn about software updates and potential fixes.
2025 Audi Q5/SQ5 Door Won't Open from Outside TSB
A Technical Service Bulletin (TSB 2079914/3) has been issued for 2025 Audi Q5 and SQ5 vehicles addressing an intermittent issue where a door cannot be opened from the outside. This can be due to software or hardware issues, sometimes accompanied by DTC B122D29.
2025 Audi Q5/SQ5 Engine Warning Lamp TSB 2081184/1
A Technical Service Bulletin (TSB 2081184/1) has been issued for 2025 Audi Q5 and SQ5 models regarding an illuminated engine warning lamp or non-functional air conditioning. This issue is linked to DTCs U366500, P2D8800, or P2D8B00, caused by an incorrectly fitted earth connection.
2025 Audi Q5/SQ5 Door Cannot Be Opened From Outside
This Technical Service Bulletin (TSB 2079914/2) addresses an issue in 2025 Audi Q5 and SQ5 vehicles where one of the doors cannot be opened intermittently from the outside, often accompanied by DTC B122D29. The TSB outlines diagnostic steps and repair procedures.
2025 Audi Q5 Side Assist Warnings TSB 2078626/3
Audi Technical Service Bulletin 2078626/3 details a fix for 2025 Audi Q5 and SQ5 models experiencing false 'side assist issues warnings' and blind spot light activation. The solution involves a software update and calibration of driver assist control units.
Leave a comment
Comments are moderated and may take a moment to appear. Only your first name and the initial of your last name are shown publicly.
Comments
Be the first to comment.