Description And Operation

DESCRIPTION 

Courtesy of CHRYSLER GROUP, LLC

The Radio Frequency Hub (RFH) (1) is located in the rear overhead compartment of the vehicle. The RFH:

• Is secured in place with two nuts
• May have two or three connections
  • A 16 way connector
  • A 20 way connector
  • A pink coaxial connector (remote start only)

The RFH overview:

• The RFH is an integrated receiver (base station) in the vehicle that interfaces with the Remote Keyless Entry (RKE) FOB using both Radio Frequency (RF) and Low Frequency (LF).
• The RFH contains the controlling logic for the PEKG feature, and the Keyless Ignition Node (KIN) lighting.
• The RFH communicates on the Controller Area Network (CAN) -C bus as well as a dedicated K-line with the KIN.
• The RFH is also hard wired to the vehicle's door handles and multiple LF antennas for purposes of providing PEKG functionality.

The RFH contains the following features:

• Remote Keyless Entry
• Keyless Go
• Passive Entry
• Keyless Ignition Node (KIN) dimming control
• Remote Start
• Tire Pressure Monitoring (TPM)

The RFH will, at a minimum, receive the following information from the KIN:

• Start/Stop Button states
• Transponder authentication in back up mode

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

• Start/Stop Button backlighting LED control
• Ignition Status Ring LED control
• RKE/FOBIK authorization to the Sentry Key Immobilizer System (SKIS)

The RFH cannot be adjusted or repaired and, if damaged or ineffective, it must be replaced.

OPERATION 

The RFH supports the following standard and optional vehicle features or systems.

• Keyless Go Ignition Systems  - In backup mode, the KIN communicates with the FOBIK through LF signals (125 KHz) then communicates it to RFH through a private serial K bus. The RFH then sends data over the bus to the BCM for IGNITION status after a valid key is verified. The RFH also contains the controlling logic for the back lighting features.

  Courtesy of CHRYSLER GROUP, LLC

• Passive Entry  - The RFH uses a high security encryption system called "AES" for Passive Entry. If the Smart door handles or exterior release switches are activated, the RFH signals the five LF antennas. The LF antenna wakes up the FOBIK then sends the challenge to confirm if it is the correct key, the FOBIK will respond with the RF with the challenge response. When a valid FOBIK is recognized by the RFH a CAN-C data bus message is sent to BCM to lock or unlock the vehicle by the RFH. A Smart door handle is identified by a smart sensor (magnet) (1) located in the door handle cap.
• Remote Keyless Entry  - The RFH receives and analyzes RF signals from the RKE FOBIK transmitter; and after a valid key is verified, relays the appropriate electronic messages to the BCM module over the CAN-C data bus to support the features of RKE functions.
• Remote Start System  - The RFH receives and analyzes RF signals received through the remote start antenna (longer range) from the RKE transmitter or the PEKG FOBIK; and after a valid key is verified, relays the appropriate electronic messages to BCM over the CAN-C data bus to support all RKE functions including optional remote start function.
• Immobilizer System SKIS  - The Immobilizer system RFH uses a high security encryption system called "AES" for Immobilizer System (IS). The system marries FOBIKs, RFH, PCM with unique secret keys for each vehicle. Swapping parts ARE NOT ALLOWED in the new system. Replacing any part of the system shall be done only in authorized dealers using the diagnostic scan tool.
• Tire Pressure Monitor System  - The RFH is an RF receiver that analyzes RF signals received from the TPM sensors and then relays the appropriate electronic messages to other electronic modules in the vehicle over the CAN-C data bus to support the features of the TPM system. The RFH will send a warning if the tire pressure is below or over the set value. If the vehicle is equipped with remote start and Passive Entry (PE) the tire pressure sensor signal is received from the external remote start antenna.

The RFH is connected to a fused B(+) circuit and has a path to a clean ground at all times. These connections allow it to remain functional regardless of the ignition switch status. Any input to the RFH that controls a vehicle system function that does not require that the ignition switch status be ON such as depressing a button on an RKE or FOBIK transmitter, prompts the RFH to wake up and transmit on the CAN-C data bus.

RFH uses On-Board Diagnostics (OBD) to monitor all of the Functions and circuits it controls, then sets active and stored Diagnostic Trouble Codes (DTC) for any monitored function faults it detects. RFH will also send electronic message requests to the Instrument Panel Cluster (IPC) for the display of certain textual warning messages related to some detected functions conditions or faults.