Terminator X gives Gen III GM 4.8/5.3/6.0 truck engines complete standalone engine control, replacing a junkyard ECU and cumbersome tuning interface with real-time fuel learn and Holley EFI's proven tuning technology at a budget-friendly price. It comes fully loaded with base maps for common LS engine combinations to get you on the road fast.
Key Features:
- Designed for GM LS engines with 24x crank reluctor and Multec 2 injectors
- Real-time fuel map learn removes the guesswork from tuning the base fuel table
- High-impedance injector drivers safely power most stock LS and Holley EFI injectors
- Bosch LSU 4.9 wideband oxygen sensor included for accurate AFR feedback
- MAP sensor vacuum hose adapters included (1/8, 1/4, and 3/16 in.)
- 4 programmable inputs (12V, ground, 5V, frequency) for extra sensors, nitrous triggers, or a trans brake
- 4 programmable outputs for fans, boost control, nitrous control, IAC, and more
- Boost control strategies: vs. time, vs. gear, vs. RPM, vs. speed, plus boost safeties
- Single-channel wet or dry progressive nitrous control with rich/lean safeties
- On-board diagnostic LEDs for ECU power, engine run, wideband status, TPS calibration, crank/cam signal
- Advanced tables: 4x 1D, 1x 1D per gear, 4x 2D, 1x 2D per gear for custom tuning needs
- Includes 3.5 in. touchscreen handheld with calibration wizard, data logging, and gauge display
- Compact ECU mounts virtually anywhere (LEDs must face up)
- Plug-and-play compatible with Holley EFI gauges, shift lights, and dash accessories (P/N 553-106, 553-111, 553-112)
- Free EFI tuning software for full laptop control
Specifications:
- Engine: Gen III GM Truck (4.8/5.3/6.0)
- Crank Reluctor: 24x, Cam Signal: 1x
- Injector Connector: Multec 2
- MAP Sensor: 1-bar, integrated
- Drive-By-Wire: No | Transmission Control: None
- Handheld Included: Yes, 3.5 in. touchscreen
- Includes: 24x LS Engine Main Harness, Multec 2 Injector Harness, Terminator X ECU, ECU Main Power Harness, Bosch LSU 4.9 Wideband O2 Sensor, I/O Harness, vacuum adapters
- Part Number: 550-904
Terminator X ECUs are designed to be mounted with the LEDs facing up.
FAQ
What engines is the 550-904 Terminator X system designed for?
It's built for Gen III GM 4.8/5.3/6.0 truck engines with a 24x crank reluctor and Multec 2 injectors.
Does this kit include a handheld for tuning?
Yes, it includes a 3.5 in. touchscreen handheld with a calibration wizard, data logging, and a customizable gauge display.
What injectors does this system support?
It's set up for Multec 2 style injectors and uses high-impedance injector drivers compatible with most stock LS and Holley EFI injectors.
Can I add boost or nitrous control with this ECU?
Yes, it has 4 programmable inputs and outputs supporting boost control strategies and single-channel wet or dry progressive nitrous control.
How should the ECU be mounted?
The Terminator X ECU should be mounted with its diagnostic LEDs facing up.