Audi Q5 (FY) — US → EU Rear Turn Signal Conversion

OEM-safe lighting logic with preserved factory behavior
 

🎯 Target Result

(PUBLIC)
Achieve EU-spec amber rear turn signals on a US-spec Audi Q5 while fully preserving:
  • Factory dynamic turn indicator
  • Separate brake and turn signal behavior
  • No errors in BCM or instrument cluster
  • Full Intelligent Light functionality
 
This solution focuses on OEM behavior, not visual modification.
 

⚠️ Problem Summary

(PUBLIC)
US-spec Audi Q5 vehicles use a combined brake/turn logic in the rear lighting system.
When converting to EU amber indicators, most common approaches result in:
  • Loss of dynamic indicator animation
  • Brake/turn signal conflicts
  • BCM or cluster error messages
  • Partial or complete loss of Intelligent Light functions
 

❌ Why Standard Solutions Fail

(PUBLIC)
Most conversion attempts rely on:
  • Simple long coding changes
  • Direct reassignment of lighting channels
  • Aftermarket signal separation
 
These methods do not account for US-specific BCM logic, where brake and turn signals share control paths that conflict with EU amber indicator behavior.
As a result, OEM lighting logic is broken even if the visual outcome initially appears correct.
 

📸 Evidence

(PUBLIC)
Screenshots:
  • BCM status overview — no active DTCs
  • Lighting function mapping confirmation
 
Video proof (30 sec):
  • Hazard lights
  • Left / right turn signals
  • Brake lights
  • Night mode with Intelligent Light active
 
(Video shows final behavior only — no coding screens.)
 

🧠 Root Cause

(PUBLIC)
The issue is not the tail lights themselves.
The root cause is a logic conflict inside the BCM, caused by differences between:
  • US brake/turn signal control architecture
  • EU amber indicator channel separation
 
Without resolving this conflict at the logic level, it is impossible to preserve both dynamic indicators and Intelligent Light behavior.
 

🔒 PAID CONTENT BELOW 🔒

 

🛠 Solution Logic

(PAID)
This solution applies a non-standard BCM logic configuration that:
  • Properly separates brake and turn signal functions
  • Maintains the factory dynamic indicator output
  • Preserves Intelligent Light system dependencies
 
The approach avoids any workaround that would introduce diagnostic errors or system inconsistencies.
This is a logic-level solution, not a cosmetic or wiring-based modification.
 

🔐 Expert Notes

(PAID)
  • The majority of available solutions sacrifice either dynamic indicators or Intelligent Light logic.
  • This configuration preserves all OEM behaviors simultaneously.
  • Applicable only to vehicles with OEM dynamic rear indicators and Intelligent Light package.
 

🧩 Compatibility & Limits

(PAID)
Tested on:
  • Audi Q5 FY (US-spec)
  • OEM rear lights with dynamic indicators
 
Not applicable to:
  • Vehicles without Intelligent Light
  • Aftermarket rear light assemblies
  • Simplified BCM configurations
 

⚖️ Legal Note

(PUBLIC)
For professional use only.
This documentation is provided for informational purposes and does not constitute step-by-step repair instructions.
No liability is assumed for misuse or improper application.