MechanMagic Smart Key Fob Remote for Nissan Sentra & Versa 2013–2019 — 4-Button CWTWB1U840, 46 Chip, 315MHz

MechanMagic Smart Key Fob Replacement (CWTWB1U840) is a ready-to-program 4-button keyless entry remote designed to replace the original Nissan Sentra and Versa push-start remotes from 2013–2019.

If your factory remote is lost, damaged, or the buttons stopped working, this MechanMagic replacement offers a cost-effective way to restore remote locking, trunk release, and push-start convenience without buying a full OEM unit. The fob ships brand-new with battery and tested electronics; it requires a qualified locksmith or dealership to cut and program the transponder before use. Double-check the FCC ID on your current remote—this unit matches CWTWB1U840 (not CWTWB1U815) and operates at 315 MHz with a 46 chip.

How do I confirm this fob fits my Nissan Sentra or Versa?

Compatibility hinges on the FCC ID and the physical button layout. Inspect your existing remote for FCC ID CWTWB1U840 and verify it’s a 4-button push-start style; if those match, this MechanMagic fob is engineered as a direct replacement.

• Check the original remote’s FCC ID: must be CWTWB1U840.
• Confirm your vehicle is a 2013–2019 Nissan Sentra or Versa.
• Ensure your vehicle uses a push-start (smart key) system.
• Use the vehicle fitment tool or product images to compare button layout.

What steps are required to get the remote working with my car?

This MechanMagic fob arrives pre-tested and with a battery, but it won’t function until the blade is cut and the transponder is professionally programmed. A locksmith or dealership can perform cutting and programming; they will sync the fob to your car’s immobilizer system so the push-start and remote functions operate normally.

• Have a qualified locksmith or dealer cut the emergency key blade.
• Ask the technician to program the 46 chip via dealer-level or locksmith tools.
• Test lock/unlock, trunk, and push-start recognition after programming.
• Retain your original fob until the replacement is confirmed to work.

What are the key technical details and quality assurances?

The MechanMagic remote complies with the specified RF and chip standards used by Nissan for the listed years. Each unit ships new, without manufacturer logos, and passes bench testing before leaving our facility to ensure consistent electronic performance upon programming.

• FCC ID: CWTWB1U840; IC ID: 1788D-FWB11U840.
• Operating frequency: 315 MHz; transponder chip: 46.
• Part numbers matched: 285E3-3SG0D / 285E33SG0D.
• Includes internal battery; fully bench-tested before shipping.

Are there any limitations or things to watch for?

This specific replacement only suits the CWTWB1U840 variant; it will not work if your existing key is model CWTWB1U815. Also, because programming involves vehicle immobilizer pairing, DIY programming is not recommended—professional tools are required to avoid lockouts or non-recognition.

• Not compatible with CWTWB1U815 remotes—match FCC ID carefully.
• Programming must be completed by a qualified locksmith or dealer.
• Designed for push-start vehicles only (smart key systems).
• Product ships with no manufacturer logo for aftermarket use.

Who this is for: Drivers of Nissan Sentra and Versa model years 2013–2019 who need an affordable, high-quality replacement for a lost or failing smart key fob. Ideal for owners who have confirmed their original remote’s FCC ID is CWTWB1U840, those who prefer a third-party replacement over an OEM-priced unit, and anyone planning to use a locksmith or dealer for cutting and programming. If you want a new, tested remote ready for professional programming that matches Nissan’s 315 MHz / 46-chip specification, this MechanMagic fob is built to meet that need.