Nexus S2 Plug ‘n’ Play Adapter Harness Kit – Mazda MX5 NA

Nexus S2 Integration Kit: NA Miata Solution

The Nexus S2 Plug ‘n’ Play Adapter Harness Kit is the complete entry point for integrating the Haltech Nexus S2 VCU into the Mazda MX-5 NA (1990-1995). This kit bundles the powerful Nexus S2 unit with the specific adaptor harness required for the B6/BP application. It offers a compact, cost-effective solution for modernizing the engine management of these iconic roadsters without the complexity of a full rewire.

Engineering for the Nexus S2

The Nexus S2 is a feature-rich VCU designed for 4-cylinder engines. This kit ensures it interfaces perfectly with the NA’s wiring. The adaptor harness routes the factory CAS and vehicle speed signals to the S2, while providing outputs for the factory tachometer and fuel pump relay. The kit includes an air temp sensor for Speed Density tuning, allowing the removal of the restrictive AFM. The S2’s onboard wideband controller (requires sensor) and data logging capabilities are fully accessible via this installation.

Operational Benefits

This kit simplifies the tuning process, providing a robust platform for everything from mild street builds to track-focused cars. The Nexus S2 offers advanced features like launch control, boost control, and flex-fuel support. The plug ‘n’ play nature of the kit means installation is quick and reversible, preserving the vehicle’s factory wiring integrity.

Fitment Guide

• Mazda MX-5 Miata: NA 1.6L & 1.8L (1990-1995)
• Transmission: Manual Only

Technical Specifications

Summary & Includes

Includes:

• 1 x Haltech Nexus S2 VCU
• 1 x Injection Molded Plug ‘n’ Play Adaptor Harness
• 1 x M14 x 1.5 Air Temp Sensor with matching plug and pins
• 1 x Auxiliary I/O 16 Pin Tyco plug and pins

Note: Manual transmission only. Not for OBDII models. TPS upgrade mandatory for 1.6L. Using S2 reduces some factory functionality compared to S3; consult guide.