Holley EFI Terminator X Max Service ECU – Replacement Controller
554-153
The Holley EFI Terminator X Max Service ECU – Replacement Controller is designed as a standalone service component for existing Terminator X and Terminator X Max installations. This replacement ECU provides real-time fuel learning, high-impedance injector control, Bosch LSU 4.9 wideband support, electronic transmission control, drive-by-wire throttle control, and advanced programmable engine-management functions.
The Terminator X Max ECU includes an integrated 1-bar MAP sensor, four programmable inputs, four programmable outputs, eight multi-color diagnostic LEDs, CAN-BUS support, data logging, boost control, progressive nitrous control, and advanced custom tables. It is compatible with all Terminator X harnesses, but the available functions still depend on the engine harness, transmission harness, throttle-body configuration, sensors, and calibration used in the installation.
Includes:
- (1) Holley EFI Terminator X Max Service ECU
- Integrated 1-Bar MAP Sensor
- Integrated Bosch LSU 4.9 Wideband Controller
- Eight Built-In Multi-Color Diagnostic LEDs
- Harnesses, Sensors, Wideband Oxygen Sensor, and Mounting Hardware Sold Separately
Specifications
| Specification | Details |
|---|---|
| Manufacturer | Holley EFI |
| Part Number | 554-153 |
| Product Type | Terminator X Max Service ECU |
| Part Type | Engine Control Module |
| Harness Compatibility | All Terminator X Harnesses |
| Injector Support | High-Impedance OEM and Performance Injectors |
| Wideband Control | Genuine Bosch LSU 4.9 |
| LSU 4.2 Compatibility | No |
| Internal MAP Sensor | 1 Bar |
| Programmable Inputs | 4 |
| Programmable Outputs | 4 |
| Drive-By-Wire Control | Yes |
| Transmission Control | Yes |
| 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 |
| EGT Support | Yes |
| Traction Control Support | Yes |
| Coil-Per-Cylinder Ignition Support | Yes |
| Terminal Gender | Male |
| Terminal Quantity | 114 |
| Mounting Hole Quantity | 4 |
| Length | 9.60" |
| Width | 5.00" |
| Height | 1.63" |
| Weight | 1.44 lbs |
Fitment
| Application | Compatibility |
|---|---|
| Holley Terminator X Harnesses | Compatible |
| Holley Terminator X Max Harnesses | Compatible |
| Drive-By-Wire Engine Families | GM LS and LT, Ford Coyote, and Mopar Gen V |
| GM Transmission Control | 4L60 and 4L80 Families |
| Ford Transmission Control | 4R70W |
| Wideband Oxygen Sensor | Bosch LSU 4.9 Only |
| Vehicle Use | Racing Use Only Vehicles |
| Marine Applications | Not Recommended |
Fitment Notes
- Designed as a service replacement ECU for compatible Terminator X and Terminator X Max installations.
- Compatible with all Terminator X harnesses, but available functions depend on the harnesses and components installed.
- Drive-by-wire control supports compatible GM LS and LT, Ford Coyote, and Mopar Gen V throttle-body systems.
- Transmission control supports compatible GM 4L60 and 4L80 families and Ford 4R70W applications.
- 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.
- Harnesses, sensors, throttle pedal, throttle body, transmission harness, wideband sensor, and mounting hardware are not included.
- Verify engine harness, crank and cam configuration, injector type, throttle-body compatibility, transmission type, and ECU calibration before ordering.
- 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.
- For off-road use, mount the ECU in a dry location protected from heat, impact, and excessive vibration, with proper wiring support and strain relief.
Tech Insight
1. Is this a complete Terminator X Max system?
No. This is a service replacement ECU intended for an existing Terminator X or Terminator X Max installation. Engine harnesses, transmission harnesses, sensors, wideband oxygen sensor, main power wiring, throttle components, and other system parts are sold separately.
2. What is the difference between the Terminator X and Terminator X Max ECU?
The Terminator X Max adds electronic transmission control and drive-by-wire throttle-body control. The usable functions depend on the correct engine, throttle, transmission, and input/output harnesses being installed and properly configured.
3. Can this ECU control a boosted or nitrous engine?
Yes. It supports boost versus time, gear, RPM, and speed strategies, along with boost safeties. It also supports a single wet or dry nitrous channel with progressive or non-progressive control, rich and lean safeties, and closed-loop air-fuel targeting.
4. What can the programmable inputs and outputs control?
The four inputs can accept 12-volt, ground, 5-volt, or frequency-based signals from pressure sensors, switches, nitrous triggers, trans brakes, and other devices. The four ground or PWM outputs can operate relays, fans, boost solenoids, nitrous controls, compatible IAC hardware, and other accessories.
5. What should be checked before replacing an existing ECU?
Confirm the original ECU type, harness compatibility, engine configuration, injector impedance, wideband sensor type, drive-by-wire components, transmission type, firmware, calibration file, and power and ground integrity. A wiring or sensor fault should be corrected before installing the replacement ECU.
