Holley Terminator X service ECU 554-152 with yellow wire on a white background, featuring &
A black side-view dimensioned drawing of a replacement Terminator X ECU with red measurement lines and labels showing 5.1 inches, 4.
Holley EFI standalone service controller dimensioned drawing top view of a black electronic control box with mounting hole details and measurements on a white background.
Terminator X ECU replacement module with two sockets and a yellow cable on a white background
Holley ECU for Terminator X harness with yellow wire on a white background
Black Terminator X ECU harness with yellow wire on a white background
Black replacement Terminator X ECU with a yellow cable on a white background
Holley Terminator X service ECU 554-152 with yellow wire on a white background, featuring &
A black side-view dimensioned drawing of a replacement Terminator X ECU with red measurement lines and labels showing 5.1 inches, 4.
Holley EFI standalone service controller dimensioned drawing top view of a black electronic control box with mounting hole details and measurements on a white background.
Terminator X ECU replacement module with two sockets and a yellow cable on a white background
Holley ECU for Terminator X harness with yellow wire on a white background
Black Terminator X ECU harness with yellow wire on a white background
Black replacement Terminator X ECU with a yellow cable on a white background

Holley EFI Terminator X Service ECU – Replacement Controller

554-152

$913.95
/
Shipping calculated at checkout.

The Holley EFI Terminator X Service ECU – Replacement Controller is a standalone replacement electronic control unit designed for use with compatible Terminator X harnesses. This service ECU restores the core engine-management functions of an existing Terminator X installation without requiring the purchase of a complete EFI system.

The ECU supports real-time fuel learning, high-impedance injectors, Bosch LSU 4.9 wideband control, an internal 1-bar MAP sensor, advanced boost and nitrous strategies, data logging, and four programmable inputs and outputs. Eight built-in multi-color diagnostic LEDs provide quick visual feedback for power, sensor, crank, cam, throttle-position, and oxygen-sensor related issues.

Includes:

  • (1) Holley EFI Terminator X Service ECU
  • Integrated 1-Bar MAP Sensor
  • Integrated Bosch LSU 4.9 Wideband Controller
  • Eight Built-In Multi-Color Diagnostic LEDs
  • Mounting Hardware, Harnesses, Sensors, and Oxygen Sensor Sold Separately
Specifications
Specification Details
Manufacturer Holley EFI
Part Number 554-152
Product Type Service ECU
Harness Compatibility Compatible Terminator X Harnesses
Injector Support High-Impedance Injectors
Wideband Control Bosch LSU 4.9
LSU 4.2 Compatibility No
Internal MAP Sensor 1 Bar
Programmable Inputs 4
Programmable Outputs 4
Diagnostic LEDs 8 Multi-Color LEDs
Boost Control Yes
Progressive Nitrous Control Yes
Multi-Stage Nitrous Control No
CAN-BUS Support Yes
Data Logging Yes
E85 Support Yes
Traction Control Support Yes
Terminal Gender Male
Terminal Quantity 62
Mounting Holes 4
Length 7.45"
Width 5.00"
Height 1.63"
Weight 1.15 lbs
Fitment
Application Compatibility
Holley Terminator X Harnesses Compatible
Holley Terminator X Max Functions Not Listed for This ECU
Wideband Oxygen Sensor Bosch LSU 4.9 Only
Vehicle Use Racing Use Only Vehicles
Marine Applications Not Recommended

Fitment Notes

  • Intended as a service replacement ECU for compatible Holley Terminator X harnesses.
  • Verify the existing harness, ECU connector, engine configuration, ignition type, injector type, and software setup before ordering.
  • This listing describes the Terminator X service ECU identified as PN 554-152.
  • Although the source information also discusses Terminator X Max features, it does not confirm that PN 554-152 provides transmission control or drive-by-wire control.
  • Requires a genuine Bosch LSU 4.9 wideband oxygen sensor and will not operate with an LSU 4.2 sensor.
  • The internal 1-bar MAP sensor can be disabled when using a compatible external MAP sensor on boosted applications.
  • Legal for sale or use only on vehicles used exclusively for competition that are not registered and may never be used on public roads.
  • Not recommended for marine applications.
  • Off-road installations should keep the ECU dry, protected from heat, and mounted with proper wiring support and strain relief.
Tech Insight

1. Is this a complete Terminator X EFI kit?

No. This is a standalone service ECU intended to replace the controller in an existing compatible Terminator X installation. Harnesses, sensors, wideband oxygen sensor, power wiring, and other EFI components are not listed as included.

2. Can this ECU be used with a Bosch LSU 4.2 oxygen sensor?

No. The ECU is designed for a genuine Bosch LSU 4.9 wideband oxygen sensor and will not operate with an LSU 4.2 sensor.

3. What do the four inputs and four outputs support?

The programmable inputs can accept 12-volt, ground, 5-volt, and frequency-based signals for sensors and activation triggers. The outputs can provide ground or PWM control for devices such as electric fans, boost-control solenoids, nitrous systems, and compatible idle-air-control hardware.

4. Can this ECU be used on a boosted engine?

Yes. The ECU supports advanced boost-control strategies. For combinations that exceed the range of the internal 1-bar MAP sensor, the internal sensor can be disabled and a compatible external MAP sensor can be used.

5. How do the built-in diagnostic LEDs help during installation?

The eight multi-color LEDs provide visual status information that can help identify setup and sensor problems, including failed throttle-position autoset, crank or cam signal faults, and possible wideband oxygen-sensor issues.

Related Products