Lear Smart Key Fob (FCC ID CWTWB1U8) – PCF7952 315 MHz Key Guide

By Mohammad H. Abdelhadi, ALOA-Certified Master Locksmith, mobile automotive locksmith. Reviewed by Ray Obar, Master Locksmith. Updated June 1, 2026.

Used across several Nissan platforms spanning 2010 through 2022, the Lear Smart Key Fob (FCC ID CWTWB1U8) serves as the factory proximity-entry and push-to-start transmitter for models including the Cube, Juke, Sentra, Versa, and Sylphy. Each Lear Smart Key Fob (FCC ID CWTWB1U8) integrates a PCF7952 transponder chip paired with 315 MHz RF communication, enabling both passive immobilizer authentication and remote keyless functions. For automotive locksmiths, the fob presents a well-documented but multi-step enrollment process requiring compatible diagnostic hardware. Owners needing a replacement typically find that dealer programming costs and wait times make independent locksmith service an attractive alternative. A correctly paired Lear Smart Key Fob (FCC ID CWTWB1U8) will authenticate with the vehicle’s Body Control Module over 315 MHz and simultaneously pass immobilizer challenge-response via its embedded PCF7952 crypto element.

Technical Specifications of the Lear Smart Key Fob (FCC ID CWTWB1U8)

The FCC filing under ID CWTWB1U8 identifies this unit as a Lear Corporation product operating at 315 MHz, a frequency standard for the North American and select Asian-market Nissan models it supports. The PCF7952 transponder inside the fob handles the cryptographic handshake with the vehicle’s immobilizer system. This chip uses a rolling-code architecture that generates a unique response to each ignition-cycle challenge, preventing replay attacks. Unlike simpler transponder-only keys, this smart key performs dual-channel communication: a low-frequency (LF) antenna in the vehicle detects the fob’s presence for passive entry and push-button start, while the 315 MHz UHF channel carries lock, unlock, and trunk-release commands initiated by button presses on the remote.

Lear Corporation, a major Tier 1 automotive supplier, manufactured these units as original equipment for Nissan. The housing typically features a matte-black case with an integrated emergency key blade slot, though blade profile specifics vary by model and market. Technicians should note that the PCF7952 chip inside this device is soldered to the fob’s internal circuit board, meaning chip-swap procedures require micro-soldering skills and appropriate rework equipment if aftermarket shells are used.

Vehicle Fitments

The following Nissan models are validated fitments for this smart key fob:

• Nissan Cube — 2011 through 2014 model years
• Nissan Juke — 2010 through 2013, and 2014 through 2018 model years
• Nissan Sentra — 2013 through 2019 model years
• Nissan Sylphy — 2020 through 2022 model years
• Nissan Versa — 2012 through 2019 model years

These vehicles share a related electrical architecture under Nissan’s B-platform and related derivatives, which is why a single FCC-registered fob design covers such a broad range of models and production years. However, locksmiths should verify the specific part number stamped on the back of the original unit before ordering a replacement, since certain mid-cycle refreshes may have switched to updated housings or slightly different internal board revisions while retaining the same FCC ID.

Programming and Enrollment Procedures

Registering the Lear Smart Key Fob (FCC ID CWTWB1U8) to a compatible Nissan requires a diagnostic scan tool capable of accessing the vehicle’s Intelligent Key system through the OBD-II port. The enrollment sequence typically involves the following stages:

1. System access: Connect a compatible programmer (such as an Autel IM608 Pro, Xtool X100 PAD3, or equivalent) to the vehicle’s OBD-II connector. Navigate to the Nissan Intelligent Key registration menu.
2. Existing key verification: If at least one working smart key is available, the system will prompt the technician to place each registered fob on the dashboard or near the steering column antenna to verify existing credentials before adding new ones.
3. New fob registration: Follow the on-screen prompts to register the replacement unit. The PCF7952 transponder inside the device will undergo a seed-key exchange with the BCM, binding it to that specific vehicle.
4. Functional test: After registration, test passive entry by approaching the vehicle with the fob in a pocket or bag. Verify push-to-start ignition, remote lock, remote unlock, and panic functions.

If no working keys are available — commonly referred to as an all-keys-lost scenario — the procedure becomes more involved. The technician will typically need to extract security data (PIN or seed) from the BCM, which may require direct wiring access to the module depending on the diagnostic platform in use. Some tools support this extraction via OBD-II alone for these Nissan models, while others require a CAN-bridge connection. Always confirm tool compatibility with the specific model year before quoting the job.

Battery Replacement and Maintenance

The fob uses a standard CR2032 lithium coin cell. When the battery voltage drops below the operating threshold, the vehicle’s instrument cluster will display an “Intelligent Key battery low” warning. To replace the battery:

1. Release the emergency mechanical key blade from the back of the unit by pressing the small release button on the housing.
2. Use the tip of the removed blade — or a small flathead screwdriver wrapped in tape to prevent marring — to gently pry the two halves of the case apart along the seam.
3. Remove the depleted CR2032 cell and insert a fresh one with the positive (+) side facing the correct direction as marked on the circuit board.
4. Snap the case halves back together and reinsert the emergency blade.

Battery replacement does not erase the transponder registration. The fob will continue to operate normally with the new cell. However, if the battery has been dead for an extended period and the owner cannot start the vehicle using passive entry, pressing the start button with the fob held directly against it will allow the LF antenna to power the transponder inductively, enabling ignition even with a completely dead battery.

OEM vs. Aftermarket Considerations

Aftermarket versions of this smart key are available from multiple suppliers and typically cost significantly less than OEM units sourced through Nissan dealerships. When evaluating aftermarket options, locksmiths should confirm that the replacement includes a genuine PCF7952 transponder — counterfeit chips are occasionally found in the lowest-priced units and will fail during the registration handshake. A reliable test is to read the chip ID with a transponder identification tool before attempting vehicle registration; a legitimate PCF7952 will return the expected chip family identifier.

The housing quality of aftermarket fobs can vary. Common issues include loose battery contacts, slightly misaligned button pads, and emergency blade slots that do not grip the blade securely. For customers who prioritize fit and finish, OEM-sourced units remain the benchmark. For cost-conscious vehicle owners, a quality aftermarket unit programmed by a qualified locksmith delivers equivalent functional performance at a fraction of the dealer price.

When to Call a Locksmith

Vehicle owners with a Nissan Cube, Juke, Sentra, Versa, or Sylphy that uses this fob should consider professional locksmith service in any of these situations: a lost or stolen smart key requiring immediate replacement, a damaged unit with cracked housing or water intrusion, the need for a spare key to avoid the higher cost of an all-keys-lost scenario later, or persistent “key not detected” warnings despite a fresh battery. A mobile automotive locksmith equipped with Nissan-compatible diagnostic tools can typically complete the full replacement and programming process on-site, eliminating the tow-to-dealer step and reducing both time and expense.

Related help: Nissan auto locksmith, car key replacement, car key programming.

Compatible and related keys: Nissan 3-Button Remote Head Key, related key: Aftermarket Smart Key Fob, related key: Aftermarket Transponder Key, Lear Smart Key Fob (FCC ID CWTWBU735) (compatible fob), Nissan/Infiniti OEM Remote Key Fob, Nissan Transponder Key, compatible Continental Automotive Smart Key Fob (FCC ID KR5TXN7), Nissan Smart Key Fob.