Haltech NEXUS Rebel LS – Gen III LS Complete Standalone ECU Kit

The Easy Way to Put a Modern Standalone ECU on Your Gen III LS

Building an LS-swapped project shouldn't require weeks of wiring diagrams, custom harness fabrication, relay panels, and trying to figure out which sensor connector belongs where.

The Haltech NEXUS Rebel LS Gen III Complete Kit gives you a modern standalone engine management system, a fully terminated Gen III LS engine harness, wideband O2 sensor, air temperature sensor, transmission wiring, alternator adapters, and the hardware needed to get your LS-powered project up and running.

Designed specifically for Gen III GM LS engines, this package takes much of the complexity out of standalone ECU installation.

Perfect for:

• LS-Swapped Cars

• Hot Rods

• Muscle Cars

• Resto-Mods

• Drag Cars

• Road Race Cars

• Off-Road Builds

• Custom Trucks

• Boats

• Dedicated Competition Vehicles

If you're starting with a Gen III LS1, LS6, or compatible Gen III LS-based engine and want modern standalone control without building an engine harness from scratch, this is the package.

Complete Gen III LS Package

The Gen III Rebel LS kit includes the ECU and terminated harness system needed to control the engine.

Included in the Kit

• Haltech NEXUS Rebel LS ECU

• Gen III LS Main Engine Harness

• Cable Throttle + Idle Air Control Sub-Harness

• LS EV1 Injector Sub-Harness

• T56 Transmission Harness

• 2-Pin Bosch Alternator Harness

• 4-Pin Delco Alternator Harness

• 2-Pin Yazaki Alternator Harness

• Gen III Knock Sensor Adapter

• Bosch LSU 4.9 Wideband O2 Sensor

• Weld-On Wideband O2 Bung

• M14 x 1.5 Intake Air Temperature Sensor

• Weld-On Air Temperature Sensor Bung

Everything is designed to work together as a complete engine-management package for compatible Gen III LS combinations.

Designed Specifically for Gen III LS Engines

This version is intended for Gen III GM LS engines, commonly including applications based around:

• LS1

• LS6

• Other Compatible Gen III LS-Based Engines

The Gen III package is designed around the typical Gen III configuration including:

• Cable Throttle

• Idle Air Control Valve

• EV1 Injectors

• Gen III Knock Sensors

If your engine has been converted to Gen IV components such as drive-by-wire, EV6 injectors, or later sensors, Haltech's modular breakout harness system allows additional components to be integrated.

No Custom Engine Harness Required

One of the biggest advantages of the Rebel LS package is the terminated engine harness.

You do not have to start with a universal harness and individually wire:

• Injectors

• Coils

• Crank Sensor

• Cam Sensor

• Throttle Position Sensor

• Idle Valve

• Knock Sensors

• Coolant Temperature

• Intake Air Temperature

• Fuel Pump Control

• Cooling Fans

• Wideband

• Alternator

• Transmission Speed Sensor

The harness is already labeled and configured for its intended function.

Plug the labeled connectors into the corresponding engine components and complete the required vehicle-side power, ground, fuel-pump, fan, and supporting connections.

This dramatically reduces the amount of wiring and configuration required compared with a traditional universal standalone installation.

More Than Just an ECU

The Rebel LS was designed specifically to simplify LS swaps.

Instead of giving you a completely blank universal ECU where every pin has to be assigned manually, Haltech pre-configures the essential engine inputs and outputs.

That means less time spent:

• Building Pinouts

• Assigning ECU Outputs

• Configuring Trigger Inputs

• Creating Harnesses

• Troubleshooting Incorrect Wiring

• Wondering Which Output Should Control What

The system is designed to get you to the important part faster:

Getting the engine running and tuned.

Built-In Setup Wizard

When you first connect to the Rebel LS through Haltech NSP, the ECU includes an easy setup wizard.

The wizard asks for information about your combination such as:

• Engine Configuration

• Compression Ratio

• Camshaft

• Injectors

• Ignition Coils

• Other Engine Components

The ECU then uses that information to establish the initial configuration and starting fuel and ignition maps.

This gives you a much better starting point than beginning with a completely blank standalone calibration.

Advanced Long-Term Learning

The Rebel LS includes Haltech's long-term learning strategy.

The ECU can use information from areas such as:

• Air/Fuel Ratio

• Ignition Calibration

• Knock Feedback

• Idle Quality

to continuously refine applicable corrections while the engine operates.

This does not replace professional tuning, but it gives the Rebel LS another layer of adaptability that makes it particularly attractive for street-driven LS swaps and projects where drivability matters.

Built-In Wideband O2 Controller

A Bosch LSU 4.9 wideband O2 sensor is included with the kit.

The Rebel LS has an onboard wideband controller, meaning you do not need to purchase a separate standalone wideband controller for the primary sensor.

The wideband can be used for:

• Air/Fuel Monitoring

• Closed-Loop Fuel Control

• Tuning

• Datalogging

• Long-Term Learning

• Lean Protection

• Engine Safety Strategies

The system can also be expanded with additional Haltech CAN wideband controllers when needed.

Built-In 4-Bar MAP Sensor

The Rebel LS includes an internal 4-bar absolute MAP sensor, capable of measuring approximately 43.5 PSI of boost pressure above atmospheric pressure.

That makes it suitable for:

• Naturally Aspirated LS Builds

• Turbo LS Builds

• Supercharged LS Builds

• High-Boost Applications

For many combinations, there is no need to purchase an additional external MAP sensor.

Boost Control

Running a turbo or supercharged LS?

The Rebel LS provides 3D closed-loop boost control.

Depending on your configuration, your tuner can build strategies around:

• Boost Targets

• Engine RPM

• Throttle Position

• Other Operating Conditions

This provides far more control than a basic manual boost controller.

Flex Fuel Ready

The Rebel LS supports Flex Fuel.

Add a compatible ethanol-content sensor and your tuner can build a calibration that automatically compensates as ethanol percentage changes.

This can allow strategies for:

• Fueling

• Ignition Timing

• Boost

• Cold Starting

• Engine Protection

depending on your setup and calibration.

Advanced Engine Protection

One of the biggest advantages of replacing a simple factory LS ECU with modern standalone management is the ability to build real engine-protection strategies.

The Rebel LS supports multi-level engine protection.

With the appropriate sensors installed, protection strategies can be created around conditions such as:

• Low Oil Pressure

• Low Fuel Pressure

• Lean Air/Fuel Ratio

• High Coolant Temperature

• High Intake Air Temperature

• Excessive Boost

• Knock

• Sensor Failure

Instead of simply showing you that something went wrong after the fact, the ECU can be configured to react when a dangerous condition occurs.

Depending on the calibration, that can include strategies such as reducing power, limiting RPM, reducing boost, or other protective actions.

Dual Knock Control

The Rebel LS includes two pre-configured knock inputs.

This allows the ECU to monitor knock feedback from the Gen III LS knock sensor system.

When properly configured and tuned, knock information can be used as another layer of engine monitoring and protection.

Motorsport Features Included

The Rebel LS isn't limited to basic street-car engine control.

It also supports advanced motorsport functions including:

• Launch Control

• Traction Control

• Anti-Lag / Rotational Idle

• Flat Shift

• Nitrous Control

• Race Timer Functions

• Closed-Loop Boost Control

• Multi-Level Engine Protection

This means the same ECU can work on a mild street LS today and still have room for more advanced performance strategies as the vehicle evolves.

Additional User-Configurable Inputs & Outputs

Even though the essential LS engine functions are already assigned, Haltech still gives you additional configurable channels for custom features.

Available user-configurable channels include:

• 1 x 25A Output

• 5 x Digital Outputs

• 4 x Digital Inputs

• 2 x Analog Inputs

These can be used for additional sensors, switches, pumps, solenoids, warnings, and other custom functions depending on the build.

Fuel Pump & Cooling Fan Control

The Rebel LS includes dedicated high-current outputs for essential vehicle functions.

Dedicated 25A outputs are provided for functions including:

• Ignition / Injection Power

• Fuel Pump

• Cooling Fan

There is also an additional user-definable 25A output.

This helps simplify the electrical system on an LS swap by reducing the amount of external control hardware required for these functions.

T56 Transmission Harness Included

The Gen III kit includes a harness for the T56 transmission speed sensor.

The Rebel LS can also be used with other manual transmissions or mechanically controlled automatics such as:

• Powerglide

• TH350

• TH400

• Other Mechanically Shifted Transmissions

Important

This package should not be purchased under the assumption that it directly controls every factory GM electronically shifted automatic transmission.

Verify your transmission requirements before ordering.

CAN Expansion

The Rebel LS includes a dedicated Haltech CAN network.

This allows you to expand your vehicle with compatible Haltech CAN products such as:

• Haltech iC-7 Digital Dash

• Haltech CAN Keypads

• Haltech PD16 Power Distribution Modules

• CAN Wideband Controllers

• Other Compatible Haltech CAN Devices

This gives you the ability to start with a simple engine-management system and add more advanced vehicle electronics later.

32MB Onboard Datalogging

The Rebel LS includes onboard datalogging as well as laptop logging through NSP.

You can record important data such as:

• Engine RPM

• Air/Fuel Ratio

• Ignition Timing

• Knock

• MAP / Boost

• Injector Duty Cycle

• Coolant Temperature

• Intake Air Temperature

• Fuel Pressure When Equipped

• Oil Pressure When Equipped

• Additional Sensor Data

Datalogging makes troubleshooting and professional tuning significantly easier.

USB-C + Wi-Fi Connectivity

The Rebel LS communicates with Haltech NSP through high-speed USB-C and also includes onboard Wi-Fi.

One particularly useful feature is that the ECU can communicate with a laptop through USB without requiring the full vehicle electrical system to be powered.

That means much of the initial configuration can be completed before the first startup.

Gen III to Gen IV Component Flexibility

Have a Gen III engine but want to use later components?

Haltech's modular harness system makes upgrades easier.

For example, the Gen III package can be adapted for components such as:

• Drive-By-Wire Throttle

• Corvette Electronic Throttle Pedal

• EV6 Injectors

• Different Alternator Configurations

using the appropriate Haltech breakout harnesses.

This means you don't necessarily have to cut apart the supplied engine harness just because your combination uses a few later-model components.

Important — This Is NOT a Factory Vehicle Plug-In ECU

The term PNP / Plug-and-Play on an LS swap can be misleading, so this is important.

The NEXUS Rebel LS is not designed to replace the ECU in a complete factory GM vehicle while retaining all factory electronics.

It does not plug directly into the original vehicle ECU harness and is not intended to communicate with the factory vehicle CAN network in the same way the OEM ECU does.

Factory systems such as:

• Factory Instrument Cluster

• ABS

• Body Control Module

• Factory Vehicle CAN Functions

• Other OEM Modules

may not function as they did with the original ECU.

This system is designed primarily for LS swap and custom vehicle applications using the included terminated engine harness.

If you are trying to install a standalone ECU into an otherwise complete factory GM vehicle, contact us before purchasing.

Perfect for LS Swap Projects

The Rebel LS is especially well suited to combinations such as:

• LS-Swapped Fox Body Mustang

• LS-Swapped Honda

• LS-Swapped Nissan

• LS-Swapped BMW

• LS-Swapped Hot Rod

• Classic Camaro

• Classic Chevelle

• Classic C10

• Resto-Mod

• Drag Car

• Road Race Build

• Custom Truck

• Tube-Chassis Vehicle

If the goal is to put a Gen III LS into a project and control the engine with modern standalone management, this kit eliminates a huge amount of unnecessary complexity.

FREE Startup Support Included

When you purchase your Haltech NEXUS Rebel LS from Kugan Tuning, we include startup and setup support.

We can assist with:

• Haltech NSP Setup

• ECU Connection

• Initial Configuration

• Injector Setup

• Ignition Coil Configuration

• MAP Setup

• Wideband Setup

• Trigger Verification

• Sensor Verification

• Fuel System Setup

• First Startup

• Idle Setup

• Initial Datalog Review

• Basic Troubleshooting

Our goal is to help you get from:

“I have an LS sitting in my project”

to:

“The engine is running and ready to tune.”

Custom Tuning Available

Startup support and an initial configuration are not the same as a complete custom tune.

For maximum performance, drivability, and engine protection, we recommend professional tuning around your exact combination.

Custom tuning can account for:

• Engine Displacement

• Compression Ratio

• Camshaft

• Cylinder Heads

• Intake Manifold

• Injectors

• Fuel Pressure

• Fuel Type

• Turbocharger

• Supercharger

• Boost Level

• Exhaust

• Additional Sensors

Remote tuning and dyno tuning services are available separately.

Why Choose the NEXUS Rebel LS?

You could build a standalone system from scratch.

Buy an ECU.

Build a harness.

Wire relays.

Assign every input.

Assign every output.

Configure the triggers.

Wire the wideband.

Figure out the transmission speed sensor.

Find the correct alternator connector.

Then troubleshoot all of it.

Or you can start with a system Haltech designed specifically around the LS platform.

With the Rebel LS Gen III package you get:

• LS-Specific Standalone ECU

• Fully Terminated Engine Harness

• Gen III Sensor Compatibility

• Wideband O2 Included

• Intake Air Temperature Sensor Included

• T56 Speed Sensor Harness

• Multiple Alternator Harnesses

• Built-In 4-Bar MAP Sensor

• Flex Fuel Capability

• Boost Control

• Knock Control

• Launch Control

• Traction Control

• Engine Protection

• Datalogging

• CAN Expansion

• USB-C

• Wi-Fi

• Kugan Tuning Startup Support

Build Your Gen III LS the Easy Way.

Order the Haltech NEXUS Rebel LS Gen III Complete Kit and get a complete modern engine-management package designed to make your LS swap simpler, cleaner, and easier to tune.