Mercury Marine / Mercruiser OEM Ecm F30/40, 77-87843302S

Brand new, genuine Mercury Mercury Marine / Mercruiser OEM Ecm F30/40, 77-87843302S. This is a factory original equipment item, not aftermarket.

This is the genuine factory Mercury Marine ECM (Engine Control Module) for 30–40 HP 3-cylinder 4-stroke outboards (F30/F40). Fully engineered to OEM specifications, it controls critical engine functions—such as ignition timing, fuel injection, and sensor diagnostics—ensuring smooth performance and reliable operation in marine environments. The module is hermetically sealed, meeting rigorous environmental standards for vibration, temperature extremes, water spray, and corrosion. Packaged with GTIN packaging for authenticity (UPC 745061529014), this ECM directly replaces previous part numbers 878433A2 and 856178T3. Designed to plug into existing harnesses with no modifications, it’s a factory-direct solution for modernizing older engines or replacing failed units.

• OEM factory module—ensures exact performance and compatibility
• Sealed housing protects against moisture, vibration & corrosion
• Direct plug-and-play installation; controls ignition & fuel systems
• Supersedes part numbers 878433A2 and 856178T3

SKU# 77-87843302S

Fits:

Compatible with 30 HP and 40 HP 3-cylinder 4-stroke Mercury/Mariner outboards under specific serial-number ranges (e.g., 0P153500–1C018825). Confirm exact engine serial-number range via service manual or dealer lookup.