Drive By Wire Harness GM

The Holley Drive By Wire Harness for GM (part number 558-406) is a purpose-built EFI wiring harness designed to integrate drive-by-wire throttle control with Holley's Dominator EFI management system on General Motors platforms. This harness eliminates mechanical cable linkage and replaces it with electronic throttle body command, enabling precise fuel and ignition management across the full RPM range.

The harness connects the Dominator EFI controller to the electronic throttle actuator and associated sensors on GM engines, translating driver input into digital throttle commands. This architecture improves cold-start response, idle stability, and transient throttle response compared to cable-controlled systems. The wiring is factory-pedigree quality, with proper gauge conductors and sealed connectors rated for engine bay heat and vibration. At 1.14 lbs and compact dimensions, the harness routes cleanly without interfering with engine bay components, reducing installation complexity on retrofit projects.

This harness is essential for builders converting carbureted or older fuel-injected GM engines to modern Dominator EFI control. It's used in street rods, restorations, performance swaps, and marine applications where OEM wiring is unavailable or incompatible. The drive-by-wire architecture also supports auxiliary functions like progressive nitrous control, boost management, and launch control integration when paired with compatible tuning software.

Holley Dominator systems are recognized in the EFI aftermarket for flexibility and tuning resolution. This harness is the critical interface between the controller and throttle body—installation accuracy and connector security directly impact drivability and reliability. Each harness is sold as a single unit and should be paired with the appropriate Dominator EFI baseplate and throttle body assembly for your engine platform.