Audi A4 Fog Lights: Specs, Fitment & Common Faults
On the A4, multiple lights failing together has genuinely been traced to a bad fuse box with several melted fuses inside — plus a confirmed Technical Service Bulletin for bi-xenon headlight flickering.
Illustration for editorial purposes
Opens live listings in a new tab.
Audi A4 Fog Lights: OEM Part Number
Audi A4 Fog Lights: Rarely Used, Easy to Forget About Until Needed
The Audi A4's fog lights sit idle for the vast majority of owners most of the year, which is exactly why a fault can go undetected for months — surfacing only on the one properly foggy morning when it matters most.
Audi A4 Fog Lights: What It Does
Front fog lights are angled and positioned to illuminate the road surface in low visibility conditions without creating the glare a standard headlight beam would in fog. Some higher trims of the A4 integrate fog lights into the same housing as cornering lights or daytime running lights, which affects both the part number and the complexity of any repair.
Fitment & Compatibility
Audi A4 Fog Lights: Generations, Derivatives & Fog Light Type
| Standard trims, halogen headlight cars | Front fog lights are conventional halogen units, and genuinely double as static cornering lights on cars without HID/adaptive headlights — this cornering function is coding-enabled rather than always active from the factory |
|---|---|
| R-Line/higher trims, LED headlight cars | Genuine LED fog lights become available, with cornering function built into the main headlight unit instead of the fog light on cars with the full adaptive lighting package |
Not every trim level of the A4 comes with fog lights fitted as standard, and the housing design often differs between trims that have them integrated with other lighting functions and those with a standalone unit. Always confirm your specific trim's fitment before ordering. Whether you're sourcing a replacement fog lights for your Audi A4 from a dealer, specialist, or online marketplace, always check compatibility against your registration or VIN before buying, and confirm you're ordering the correct side — driver's side (RH in the UK) or passenger side (LH in the UK) — since these are not interchangeable.
Opens live listings in a new tab.
A Genuinely Alarming, Real Finding Worth Knowing — Audi A4 Fog Lights
If multiple lights fail together, this is genuinely worth knowing: documented cases describe several lights going out around the same time being traced to a genuinely faulty fuse box, with individual fuses found melted inside it. It's also genuinely worth knowing a confirmed technical service bulletin exists covering certain models fitted with bi-xenon headlights, describing a xenon light sporadically flickering before going out, or failing permanently.
It's also genuinely worth knowing that a complete lack of power to the front fog lights has, in documented cases, simply been down to dirty contacts or a relay not fully seated in its socket, rather than a genuine component failure.
Audi A4 Fog Lights: Common Faults, DIY Difficulty & Aftermarket Advice
These are the same regardless of make or model — see our full Fog Lights Guide for common faults to check for (including exactly what fails an MOT), how easy this job is to DIY, and aftermarket advice.
More Audi Fog Lights
The same part, covered across other Audi models.