Holley Dominator pinout and specs

Checked against the maker's documents 27 September 2026

Holley Dominator is a 172-pin wire-in Holley ECU on 6 connectors: J1A (34 pins), J1B (26 pins), J2A (34 pins), J2B (26 pins), J3 (26 pins) and J4 (26 pins).

It has 12 injector outputs and 12 ignition outputs. The injector drivers are peak-and-hold, so low-impedance injectors run without a resistor pack. The ignition outputs are logic-level. Smart coils plug straight in; dumb coils need an igniter in between.

There are 2 dedicated trigger inputs, each happy with a VR or a Hall sensor. Two knock inputs cover both banks of a V engine. It has 2 onboard wideband controllers, so a sensor wires straight in. MAP is an external sensor on an analog input.

It has H-bridge outputs labelled for an electronic throttle, so drive-by-wire runs from the ECU itself. Two CAN buses handle dashes, PDMs and expansion. 21 outputs can switch 12V as well as ground.

Spec sheet

Which builds it suits

Of the 58 swap presets in the planner, 28 fit as they are and 29 fit with add-ons; 1 does not fit at all. The add-on it asks for most often is an external igniter. Where it falls short, it is usually not enough knock inputs. The planner fills anything a preset leaves open with its ordinary defaults, so your own build may land differently.

It runs the GM LS L76 (Gen4 6.0 alum), Nissan VR38DETT (R35 GT-R), Subaru EJ/FA EJ20 turbo single-AVCS (EJ207 v7-9) and Mazda Rotary 13B-MSP Renesis (RX-8 auto, 4-injector) presets with nothing added. The Ford Coyote 5.0 Gen3 (2018-23) needs an external igniter. The Subaru EJ/FA FA20DIT (WRX turbo 2015+) needs a direct-injection driver module. It can't run the BMW S54 (3.2 NA I6, E46 M3): not enough knock inputs.

Plan a build around the Holley Dominator

Pin table

By connector: J1A carries 2 trigger inputs, 2 knock inputs and 8 analog inputs; J1B carries 8 injector outputs, 8 ignition outputs and 4 H-bridge outputs; J2A carries 19 analog inputs, 4 digital inputs and 8 wideband pins; J2B carries 4 injector outputs and 4 ignition outputs; J3 carries 9 analog inputs, 4 H-bridge outputs and 1 CAN bus.

Other Holley ECUs

The closest Holley unit is the Holley Terminator X Max. Against it, this one has 12 injector outputs (the Terminator X Max has 8), 12 ignition outputs (the Terminator X Max has 8), 2 wideband controllers (the Terminator X Max has 1) and 2 CAN buses (the Terminator X Max has 1).

• Holley Terminator X Max
• Holley HP EFI
• Holley Terminator X

Source: Holley documentation for the Dominator

Always verify against the manufacturer's manual and your tuner before wiring.