Description And Operation

Courtesy of CHRYSLER GROUP, LLC

DESCRIPTION 

The Radio Frequency (RF) Hub is located behind the rear trim panel attached to the cab panel. The RF Hub:

• is secured in place with three nuts
• can have either two or three connections: a pink coaxial connector for remote start only, a 16 way connector, and a 20 way connector.

The RF Hub is an integrated receiver (base station) in the vehicle that interfaces with the key fob using both RF and Low Frequency (LF) signals.

This model RF Hub has two connector receptacles integral to the RF Hub housing and are connected to the vehicle electrical system through dedicated take outs and connectors of the body wire harness. A remote start antenna is connected directly to the RF Hub through a third integral connector receptacle.

OPERATION 

The RF Hub is an integrated receiver (or base station) in the vehicle that communicates with other electronic modules in the vehicle over either the Controller Area Network (CAN) data bus or a private serial bus. The RF Hub is also hard wired to the vehicle's door handles and multiple LF antennas. Using the data bus network and the hard wired signals, the RF Hub supports the following standard and optional vehicle features:

• Keyless Go Ignition Systems  - In backup mode, the Keyless Ignition Node (KIN) communicates with the key fob through LF signals (125 KHz) then communicates the key fob information to RF Hub through a private serial K bus. The RF Hub then sends ignition status data over the bus to the Body Control Module (BCM) after a valid key fob is verified. The RF Hub also contains the controlling logic for the back lighting features of the KIN.
• The RF Hub will, at a minimum, receive the following information from the KIN:
  • START/STOP button states
  • Transponder authentication in back up mode

  The RF Hub will, at a minimum, transmit the following information to the KIN:

  • START/STOP button backlighting control
  • Ignition status ring back lighting control
• Immobilizer System  - RF Hub uses a high security encryption system called Advanced Encryption Standard (AES) for the Immobilizer System. The RF Hub marries itself to the BCM and Powertrain Control Module (PCM) with AES at first ignition ON in the assembly plant. Then the system marries the key fobs, RF Hub, BCM and the PCM with unique secret keys for each vehicle. Swapping any of the married parts ARE NOT ALLOWED in the new system.
• Passive Entry (PE)  - The RF Hub also uses AES for PE operation. If the Smart door handles or exterior release switches are activated, the RF Hub signals the LF antennas. The LF antenna wakes up the key fob then sends a challenge to confirm if it is the correct key fob. Then the key fob will respond to the RF Hub with the challenge response. When a valid key fob is recognized by the RF Hub, a CAN data bus message is sent to BCM to lock or unlock the vehicle by the RF Hub.
• Remote Keyless Entry (RKE)  - The RF Hub receives and analyzes RF signals from the key fob; and after a valid key fob is verified, relays the appropriate electronic messages to the BCM over the CAN data bus to support the features of RKE functions.
• Remote Start System  - The RF Hub receives and analyzes RF signals received from the key fob; and after a valid key fob is verified, relays the appropriate electronic messages to BCM over the CAN data bus to support all RKE functions including optional remote start function.
• Tire Pressure Monitor System (when NOT equipped with a Tire Pressure Monitoring (TPM) Module) - 
• Pre-June 7th 2021 Build 

  Vehicles built prior to June 7th will be equipped with a Tire Pressure Monitoring System (TPMS) Module.

  Post-June 7th 2021 Build 

  The Tire Pressure Monitoring system for vehicles built after June 7th 2021 is integrated by the Radio Frequency Hub (RF Hub). A "Dummy" TPMS module may be installed with the purpose of being a pass-through for the CAN communication lines. The "Dummy" TPMS module cannot be communicated with and is not a factor in the Tire Pressure Monitoring. The RF-Hub performs the same functions below when equipped.

  The RF-Hub is able to receive tire pressure, temperature, sensor ID and function code data via RF data transmitted from the sensors inside the wheel. The RF-Hub stores all warning and fault conditions, placard pressure values, low pressure threshold values, all wheel sensor IDs and locations, and faults in memory that can be accessed through diagnostic communication. The RF-Hub software is able to be re-flashed over the CAN bus through use of a diagnostic scan tool connected to the vehicle's diagnostic connector. The RF-Hub controls the TPM indicator lamp function including conducting a bulb check operation at every ignition ON key cycle.