Standard Ignition NS-646 Neutral Safety Switch

Brand Standard Ignition NS-646
Color Black
Connector Gender Female
Finish Plastic
Material Metal
Mounting Type Bolt Mount
Terminal Gender Male
Terminal Type Blade
Fits Acura and Honda · 13 vehicles

Bolt-mount design. Installs securely with a simple bolt-on attachment method.

Metal construction. Built with a durable metal body for dependable operation.

12V electrical part. Made for standard 12-volt systems with blade terminals.

Cross-references Standard Ignition NS-646, 28900RCT014 and CWS543 for the same application. See all 5.

$179.84Free shipping
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Free returns within 60 days if it doesn't fit when fitment is verified.

Neutral Safety Switch for Acura TSX and Honda Fit

Standard Ignition NS-646 is a 12V neutral safety switch built with a metal body, black plastic finish, and a rectangular female connector. It is a bolt-mount replacement for select Acura TSX and Honda Fit applications, with 10 male blade terminals for direct electrical connection.

Key Features

  • Neutral safety switch for automatic transmission starting circuit control
  • Fits 2009-2014 Acura TSX
  • Fits 2010-2013 Honda Fit
  • 12V electrical rating
  • 10-terminal design with male blade terminals
  • Single rectangular female connector
  • Bolt-mount attachment method
  • Metal construction with black plastic finish
  • Standard Ignition NS-646 replacement part

Detailed Description

The Standard Ignition NS-646 neutral safety switch is used in the transmission start-inhibit circuit to help ensure the vehicle starts only in the proper gear position. This part cross-references Monroe Shocks & Struts (e.g., 172286, 182286) for the same application. For drivers searching for a 2009-2014 Acura TSX neutral safety switch or a 2010-2013 Honda Fit neutral safety switch, NS-646 provides the specified connector layout, terminal count, and bolt-mount design needed for a direct replacement.

What It Helps Address

  • No-crank condition when the shifter is in Park or Neutral
  • Intermittent starting caused by a worn transmission range switch
  • Incorrect starter engagement due to switch misalignment or internal wear
  • Electrical connection issues at the transmission-mounted switch
  • Transmission start-circuit faults on Acura TSX and Honda Fit models

Installation Notes

Verify the connector shape, terminal count, and mounting style before installation. This NS-646 switch uses a bolt-mount design and does not include mounting hardware or gaskets. Confirm the transmission range adjustment after installation so the starter circuit operates correctly.

Quality Assurance

Standard Ignition manufactures replacement electrical components for automotive service applications. NS-646 is built to match the listed fitment and electrical specifications for the confirmed vehicle applications.

This part fits 13 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelSubmodelTransmissionLitersCylindersPositionNotes
2014AcuraTSX——2.4LL4N/A—
2013AcuraTSX——2.4LL4N/A—
2013HondaFit——1.5LL4N/A—
2012AcuraTSX——2.4LL4N/A—
2012HondaFitBase———N/A—
2012HondaFitSport———N/A—
2011AcuraTSX——2.4LL4N/A—
2011HondaFitBase———N/A—
2011HondaFitSport———N/A—
2010AcuraTSX—Automatic——N/A—
2010HondaFitBase———N/A—
2010HondaFitSport———N/A—
2009AcuraTSX—Automatic——N/A—
Directly replaces or cross-references 5 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
Standard Ignition — NS-64628900RCT014CWS543NS7048SW8738