Mercedes-Benz GLC43 AMG front turn signal uses 12174NA bulb size while rear turn signal requires 12496 bulb size. The replacement bulb chart covers 2017 to 2020 production years with corresponding specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz GLC43 AMG uses two distinct bulb types across its front and rear turn signal positions for the 2017-2020 model years: the 12174NA for the front and the 12496 for the rear.
The 12174NA is identified by its OEM part number and features natural amber glass, meaning the amber color is built into the glass envelope rather than achieved through a coating or lens filter.
The front turn signal application of the 12174NA is conditional, applying only to vehicles equipped with halogen capsule headlamps. GLC43 AMG units fitted with non-halogen headlamp systems do not use this bulb in the front turn signal position.
Both the 12174NA and the 12496 operate on a 12V electrical system, which is standard for passenger vehicle lighting circuits.
The 12496 carries a Philips/Osram part number, indicating it originates from the aftermarket or OES supply chain rather than a strictly OEM designation.
The 12496 is classified as a specialty application halogen bulb, a designation that typically indicates a non-standard base type, envelope shape, or wattage configuration compared to common automotive bulb families.
Because the front turn signal fitment of the 12174NA is tied to a specific headlamp configuration, substituting this bulb without confirming the headlamp type on a given vehicle risks an incorrect fitment.
The rear turn signal position on the GLC43 AMG uses the 12496 across all four model years without any noted conditional variants, indicating a uniform rear fitment for 2017-2020.