Honda OEM Smart Key Fob (FCC ID KR5434760) – Key Details & Info
Programming a Honda OEM Smart Key Fob (FCC ID KR5434760) requires a professional diagnostic platform capable of communicating with Honda’s immobilizer control module over the OBD-II port. The procedure begins with reading the current key registration status from the vehicle’s body control module, then initiating a cryptographic handshake between the Philips PCF7945A transponder embedded in the fob and the immobilizer ECU. Locksmiths enrolling the Honda OEM Smart Key Fob (FCC ID KR5434760) must ensure all previously registered keys are present during the process, as most Honda-family smart key systems re-register the full set in a single session. Once the device is enrolled correctly, it will communicate passive entry and push-to-start commands on the 315 MHz frequency band without additional configuration. Replacement units of this fob are available through OEM parts channels and can also be sourced as Honda OEM Smart Key Fob (FCC ID KR5434760) aftermarket-compatible shells paired with genuine circuit boards.
Technical Specifications for the Honda OEM Smart Key Fob (FCC ID KR5434760)
The core of this smart key is the Philips PCF7945A transponder chip, a well-established IC in the automotive security space. The PCF7945A combines a passive RFID transponder function for immobilizer authentication with an active RF section used for remote keyless entry and proximity detection. Operating at 315 MHz, the fob transmits rolling-code signals to the vehicle’s receiver module, which validates the encrypted payload before authorizing door unlock, door lock, or trunk release commands.
The FCC ID KR5434760 designation confirms that this unit has been tested and certified by the Federal Communications Commission for RF emissions compliance in the United States. This certification covers the 315 MHz transmission frequency, power output, and spurious emission levels — all of which must fall within Part 15 limits for intentional radiators. Locksmiths and vehicle owners should verify the FCC ID printed on the back of the fob when ordering replacements, as Honda uses different FCC IDs across model years and trim levels, and an incorrect unit will not pair with the vehicle.
Validated Vehicle Fitments
Based on verified compatibility data, this smart key is confirmed to fit the following Honda-family vehicles:
- Acura ILX — Honda’s compact luxury sedan, which uses a proximity-based smart key system across multiple model years. The ILX immobilizer module communicates with the PCF7945A chip during engine start authorization.
- Acura RDX — The compact luxury crossover SUV in the Acura lineup. The RDX’s passive entry system relies on the 315 MHz signal from this fob for walk-up unlock, push-button start, and liftgate release functions.
Both the Acura ILX and Acura RDX are manufactured under the Honda corporate umbrella and share underlying immobilizer architecture. This shared platform is why a single FCC ID covers both models, though locksmiths should always confirm the specific model year before ordering, as mid-generation refreshes can introduce updated electronics.
Programming Considerations for Automotive Locksmiths
Professional key programming tools from manufacturers such as Autel, Smart Pro, and XTOOL typically support the registration workflow for this fob. The general process involves the following stages:
- Key count read: Connect to the vehicle’s OBD-II port and query the immobilizer ECU for the number of currently registered keys.
- Gather all keys: All existing registered smart keys must be physically present and placed near the steering column or in the emergency start position during re-registration.
- Initiate registration mode: The diagnostic tool sends the appropriate seed request to the immobilizer, which responds with a challenge. The PCF7945A inside each fob computes a cryptographic response, and the ECU stores the new key ID upon successful validation.
- Proximity and RF verification: After transponder enrollment, test the 315 MHz remote functions — lock, unlock, and any additional buttons — to confirm the RF portion of the fob is communicating properly with the vehicle’s body control module receiver.
If only one key is being added to an existing set, the procedure typically completes in under five minutes. However, when performing a full key set reset — for instance, when the vehicle owner has lost all keys — the process may require a PIN code or security access credential obtained from Honda or Acura dealer records. Locksmiths without dealer access can often retrieve this information through authorized third-party databases.
OEM vs. Aftermarket Replacement Options
Genuine Honda OEM units carrying the KR5434760 FCC ID are the most reliable option for ensuring first-attempt programming success and long-term durability. OEM fobs use factory-spec PCF7945A chips that are pre-configured for Honda’s encryption protocol, eliminating compatibility variables that sometimes arise with third-party boards.
Aftermarket alternatives do exist, and many are built around the same Philips PCF7945A silicon. Quality varies significantly among aftermarket suppliers, however. Lower-cost units may use substitute transponder chips that mimic the PCF7945A’s behavior but lack full cryptographic compatibility, resulting in intermittent start failures or proximity detection issues. A qualified locksmith can test the transponder response before handing the key to the customer, catching these issues at the point of service rather than after the vehicle owner has left.
Regardless of source, the replacement fob must transmit on 315 MHz and carry the correct FCC ID to guarantee regulatory compliance and functional interoperability with the Acura ILX or Acura RDX receiver module.
Battery and Maintenance Notes
Smart key fobs of this type use a standard CR-series coin cell battery to power the active RF transmitter. When the battery weakens, the vehicle’s dashboard will typically display a key battery warning. Even with a dead battery, the PCF7945A transponder can still authenticate via the passive RFID channel if the fob is held against the push-button start switch — this is the emergency start procedure that Honda programs into all smart-key-equipped vehicles.
Replacing the battery is straightforward and does not require reprogramming. The fob shell separates along a seam, and the coin cell sits in an accessible tray. Care should be taken not to damage the internal antenna traces or the chip contacts during battery replacement.
Specifications and fitment
| Key type | Smart Key |
|---|---|
| Transponder chip | PCF7945A |
| Chip manufacturer | Philips |
| Frequency (MHz) | 315 |
| FCC ID(s) | KR5434760 |
| Region(s) | USA |
| Product type | Smart Key |
| Compatible makes | Acura |
Listed vehicle fitment
| Make | Model | Years |
|---|---|---|
| Acura | ILX | |
| Acura | RDX |
Fitment must be confirmed against the existing key’s FCC ID family and the vehicle’s exact configuration before cutting or programming. VIN or photo verification may be required.
Questions and answers
Which vehicles does Honda OEM Smart Key Fob (FCC ID KR5434760) fit?
Honda OEM Smart Key Fob (FCC ID KR5434760) is listed to fit Acura applications such as Acura ILX, Acura RDX. Confirm the exact year range and the existing key’s FCC ID family before ordering, since fitment can vary by trim and region.
Does Honda OEM Smart Key Fob (FCC ID KR5434760) need programming?
Yes. Because it carries a transponder/remote function (chip PCF7945A), it must be programmed (paired) to the vehicle’s immobilizer and, for remote functions, to the keyless-entry system. Many vehicles also require at least one working key to add a new one.
Does the blade need to be cut?
A push-to-start smart key has no traditional blade to cut in normal use, though many include an emergency insert key that can be cut separately.
Is Honda OEM Smart Key Fob (FCC ID KR5434760) OEM or aftermarket?
This listing is an aftermarket-grade replacement intended to match the original key’s electronic and mechanical specification. It is not required to carry a vehicle-brand logo and should be matched by FCC ID family and chip type rather than by appearance.
Check Fitment and Key Help
Low Rate Locksmith, a mobile automotive locksmith, can confirm whether Honda OEM Smart Key Fob (FCC ID KR5434760) matches an existing FCC ID family and coordinate cutting and programming when the vehicle configuration requires professional service. For dispatch and support, call (833) 439-8636 or email info@lowratelocksmith.com.
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