Neutral Safety Switch / Transmission Range Sensor

Precision Gear Selection and Starting Safety for 2007–2019 GM HD Trucks

Ensure your heavy-duty truck starts reliably and only in the safe positions of Park or Neutral with this high-quality Neutral Safety Switch (also known as a Transmission Range Sensor). Specifically engineered for the Chevrolet Silverado and GMC Sierra 2500/3500 HD series equipped with the 6.6L Duramax Diesel engine, this switch serves as the critical communication link between your gear selector and the vehicle’s Engine Control Module (ECM).

A faulty switch is the primary cause of "no-crank, no-start" conditions, erratic reverse light operation, or a mismatch between the shifter position and the dashboard gear indicator. This replacement unit is built with high-temperature polymer housing and corrosion-resistant electrical contacts to withstand the extreme under-vehicle environment of a hard-working HD truck.

Fitment Verification and Vehicle Applications

This switch is specifically designed for Heavy Duty (HD) 2500 and 3500 series trucks with the 6.6L V8 Diesel engine:

• Chevrolet Silverado 2500 HD / 3500 HD: 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019.

• GMC Sierra 2500 HD / 3500 HD: 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019.

• Classic Models: 2007 Silverado/Sierra 2500 HD Classic and 3500 Classic (V8 6.6L).

• Fitment Note: This component is typically mounted externally on the driver's side of the transmission. Please verify your transmission model, as this switch is vital for the Allison and 6-speed heavy-duty variants.

Technical Specifications and Attributes

• Function: Enables engine cranking in Park/Neutral and controls reverse light activation.

• Housing Material: Reinforced high-strength plastic (Heat and Oil Resistant).

• Terminal Type: Multi-pin blade connector (Verify against your existing harness).

• Adjustability: Slotted mounting holes allow for precise alignment with the mechanical shift detents.

• Fitment Type: Direct Replacement.

What’s in the Box

• (1) Neutral Safety Switch / Transmission Range Sensor Assembly

Industry Cross-Reference Numbers

• General Motors: 29542692, 29541852

• Standard Ignition: NS691

• Airtex: 1S12272

• BWD: CSW588

• Duralast: SW9337

• Echlin: NS7093

Installation and Technical Tips

• The "Alignment" Check: If your truck fails to start in Park but starts in Neutral, the switch may simply be out of adjustment. When installing the new unit, ensure the gear indicator on the dash accurately reflects the physical shifter position before fully torquing the mounting bolts.

• Inspect the Harness: Because of its location near the road surface and exhaust, the wiring pigtail can often become brittle or corroded. Carefully inspect the connector pins for green oxidation or signs of melting. Using dielectric grease on the new connection is highly recommended to prevent moisture intrusion.

• Heat Shield Maintenance: If your truck is equipped with an exhaust heat shield near the transmission, ensure it is reinstalled correctly. The heat from a heavy-towing Duramax can damage the internal electronics of the switch if the shielding is missing or improperly positioned.

• Shift Cable Inspection: While you are underneath the vehicle, check the condition of your shift cable bushings. A worn or loose cable can cause the mechanical shifter to fall "between" gears, preventing the neutral safety switch from sending the correct start signal.