Audi SQ5 Turn Signal Bulb Size

Additional Notes

• The front turn signal on the Audi SQ5 uses three distinct bulb types across its model years: the 12174NA for 2023-2024, the 12174SV for 2021, and the 12188 for 2014-2018. These are not interchangeable with one another, as each carries different optical and coating characteristics despite all operating at 12V.
• The 12174NA is an OEM-designated natural amber glass bulb rated at 12V. Its amber coloring is achieved through the glass itself rather than a coating, which is a different construction method from coated variants.
• The 12174SV is a Philips SilverVision halogen bulb rated at 12V. It uses an enhanced coating applied to the bulb surface to produce its output characteristics, distinguishing it from the natural amber glass construction of the 12174NA used in adjacent model years.
• The 12188 is a Philips halogen bulb rated at 12V and classified as a specialty application type. It serves as the front turn signal bulb across five consecutive model years, from 2014 to 2018, making it the most consistently used front turn signal bulb in the SQ5 lineup covered by these specifications.
• The rear turn signal on the Audi SQ5 uses the PY21W across multiple model years. This bulb follows the ECE standard used in Europe and worldwide markets. It is a single-filament amber bulb rated at 12V and 21W, and it uses a BAU15s bayonet base, which is an offset-pin base that prevents accidental installation of non-amber bulbs in amber-designated sockets.
• For model years 2014-2016, the rear turn signal assembly uses two separate bulb positions: the upper position takes a 7506 and the lower position takes a PY21W. These two positions are not served by the same bulb type and are not interchangeable within the assembly.
• The 2017 Audi SQ5 rear turn signal has a VIN-based split in its lower position specification. Units produced up to VIN FP-H-150 000 and those produced from VIN FY-H-000 001 both use a PY21W in the lower position, while the upper position uses a 7506 regardless of VIN range.
• The 2018 model year rear turn signal no longer lists separate upper and lower positions, with only a single PY21W specified for the rear turn signal, indicating a change in assembly configuration relative to the 2014-2017 model years.