Nexus S3 Plug ‘n’ Play Adapter Harness Kit – Mazda MX5 NB

Nexus Integration for the NB Miata: S3 Adaptor Harness

The Nexus S3 Plug ‘n’ Play Adapter Harness Kit is the essential link for installing Haltech’s Nexus S3 VCU into the Mazda MX-5 NB (1998-2005). This harness is engineered to leverage the S3’s advanced processing power on the BP-4W and BP-Z3 (VVT) platforms without the need for a custom wire-in installation. It connects directly to the factory ECU header, mapping the vehicle’s sensors and actuators to the Nexus S3’s inputs and outputs.

Engineering for the Nexus S3

This adaptor allows the Nexus S3 to take full control of the NB engine. It supports the variable valve timing (VVT) system on NB2 models and provides the necessary logic for the alternator control, which is ECU-driven on the NB chassis. The harness includes an auxiliary I/O connector, allowing users to easily add aftermarket sensors like wideband O2, fuel pressure, and oil pressure directly to the VCU. This data can then be used for advanced engine protection strategies and data logging.

Operational Benefits

With the Nexus S3 and this harness, you can unlock features like launch control, traction control, and flex-fuel tuning. The harness maintains the function of the factory dashboard, including the tachometer and check engine light. It is the cleanest way to install a Nexus S3 into an NB Miata, providing a professional, reversible installation that retains the reliability of the factory wiring loom.

Fitment Guide

• Mazda MX-5 Miata: NB1 (1998-2000) & NB2 (2001-2005)
• Engine: 1.8L BP-4W / BP-Z3
• Transmission: Manual Only

Technical Specifications

Summary & Includes

Includes:

• 1 x Nexus S3 ECU
• 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. Supports Factory Turbo models.