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Holley Terminator X Engine Management Systems 550-903 Systems, X, Up to 8-Injectors, 8-Coils, Analog input, CANBUS, Sensors, Controller, Chevy, 5.7L, 1x Cam, 24x Crank, Kit

SKU: HLY550-903

Engine Management Systems

Holley Terminator X Engine Management Systems 550-903 Systems, X, Up to 8-Injectors, 8-Coils, Analog input, CANBUS, Sensors, Controller, Chevy, 5.7L, 1x Cam, 24x Crank, Kit

SKU: HLY550-903

Engine Management Systems
A$3,360.31
IN STOCK! Est Ship 4-7 days. In stock at 2 locations (more than 10 available)

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Description

Engine Control Module - Terminator X - 3.5 in Touchscreen - Wiring Harness - 24x Reluctor Wheel - GM LS-Series - Kit


Data: v2 - Desc: v4.2 - Upd: 2026-11-08 02:15:11

Data: v4.2 - Upd: 2026-11-09 03:49:14

Features

Vehicle Compatibility and Return Conditions.

This item was designed and engineered in the USA for US domestic vehicles. OBD tools, ECUs, dongles, programmers, and tuners may have limited compatibility with vehicles outside the USA due to regional differences in emission standards and system configurations. Some features and functionality may vary depending on the vehicle and location.

Some electronic tuning devices and programmers require activation, registration, or pairing with a specific vehicle’s VIN (Vehicle Identification Number). Once activated or paired, these devices may become permanently associated with that vehicle, restricting or preventing their use on another vehicle, resticting our ability to offer returns or exchanges.

Please review the product details and images to ensure it meets your needs. For clarification or assistance, feel free to contact a StreetFX agent. Note: Returns are not accepted for special order or tuning products unless the unit is deemed faulty.

(keyword: controller)

Images are supplied by the manufacturer and may be generic. While all efforts are made to provide accurate pictures, there may be differences in the actual product, such as colour, quantity, version, or included components. Please carefully review the description and specifications for details on inclusions or any variations. Some items may be sold individually or in sets, and images may occasionally depict additional products or quantities not included in your purchase. For assistance or clarification, please contact customer support.

Specifications

Reference Information

Reference Data (Provide these details to our support team)
Brand Name/s Holley, Hilborn, Holley Efi, Retrobright, Terminator X
StreetFX SKU hly550-903
SFX Item ID 4782419
Accounting SKU hly-550-903
Manufacturer SKU 550-903
Manufacturer UPC 090127060797
Alternative References 550-903, HLY-550-903, HOL550-903

Engine Management Systems, Terminator X, Up to 8-Injectors, 8-Coils, Analog input, CANBUS, Sensors, Controller, Chevy, 5.7L, 1x Cam, 24x Crank, Kit

Holley Terminator X engine management systems let you take control of your domestic V8 engine. These kits give you complete charge of your engine and self-learning fuel strategies, along with the proven, race-winning technology of Holley EFI—all at a budget-friendly price! Every MPFI Terminator X features real-time fuel learn, high impedance injector drivers, an integrated one-bar MAP sensor—and four programmable inputs and outputs, ideal for electric fans, boost control solenoids, progressive nitrous control, and much more. All systems come fully loaded with base maps for common engine combinations to get you out of the garage and onto the road or track fast.

Features include:
• Holley EFI industry-leading, easy-to-use software suite allows full laptop access for advanced users
• Real-time fuel map learn—takes the guesswork out of tuning your base fuel table
• High-impedance injector drivers will safely power most standard injectors and Holley EFI injectors. (Will not control low-impedance injectors)
• Bosch LSU 4.9 wideband relays AFR information to the ECU for accurate reading and precise tuning control
• On-board one-bar MAP sensor is perfect for N/A or nitrous engine combos
• MAP sensor vacuum hose adapters
• 4 inputs: 12 V, ground, 5 V, and frequency
• 4 outputs: Ground, PWM for accessories
• Boost control: boost vs. time, boost vs. gear, boost vs. rpm, boost vs. speed, and boost safeties
• Nitrous control: single channel of wet or dry, progressive or non-progressive, rich/lean safeties, and target closed loop AFR; adjustable through touch screen
• Advanced tables: 4 x 1D tables, 1 x 1D per gear table, 4 x 2D tables, 1 x 2D per gear table
• On-board diagnostic LEDs allow you to identify any critical engine issues at a glance
• The compact ECU size allows you to mount it virtually anywhere. Remember, diagnostic LEDs must face up!
• Plug-and-play compatible with more Holley EFI accessories
• Available with or without a 3.5 in. touch screen LCD hand-held with easy-to-use calibration wizard; allows you to quickly build a base tune for most domestic V8 engines, as well as tuning and gauge display functions (not available with every kit)

Product Attributes
BrandHolley
Manufacturer's Part Number550-903
Part TypeEngine Management Systems
Product LineHolley Terminator X Engine Management Systems
UPC090127060797
Transmission Controller IncludedNo
Boost ControlYes
Traction ControlNo
High Impedence InjectorsUp to 8
Fuel Injector Connector StyleJetronic/Minitimer/EV1
CoilsUp to 8
Ignition Coil ConnectorGM LS/LT 4-pin
Analog Inputs4
Wideband ControllerYes
Wideband Channels1
CANBUS EnabledYes
CANBUS Networks1
Knock ControlYes
Knock Channels2
Drive-By-Wire CapableNo
VVT ControlNo
Nitrous ControlYes
Launch ControlNo
Engine ProtectionYes
Flex Fuel CompatibleYes
Multi-fuel CapableNo
Data LoggerYes
Oxygen Sensor IncludedYes
Reluctor Wheel Tooth Quantity24
Display IncludedYes
Handheld Controller IncludedYes
RemanufacturedNo
QuantitySold as a kit.
NotesTo use E85 fuel a flex fuel sensor must be purchased. Fits LS1 and LS6 engines with a 24x crank trigger, 1x cam, 1bar MAP sensor, and EV1 injector harness. Includes a 3.5 inch touchscreen display. Cable operated throttle body. Cannot program through EFI Standalone Digital Dash Kits. This kit does not operate variable valve timing (VVT) or displacement on demand (DOD) systems.

Compatibility

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