Hands Free Phone: Operation

WARNING: This page is about a different car, the 2020 Jeep Renegade. However, it is still accessible from the selected car via links, so may be relevant.

The Uconnect® Hands Free Phone system relies upon Bluetooth® technology to enable wireless connectivity between Bluetooth® compatible, paired and turned ON mobile devices and the on-board entertainment system components. This system also relies upon ASR software to enable voice commands to control the mobile device as well as the components and features of some other on-board systems.

The system will recognize up to 10 Bluetooth® compatible devices, each of which is identified within the system by the name acquired from the device during the pairing process. The Hands Free Phone system will communicate with a paired device that is anywhere within the vehicle. However, covering the paired device with a metal object may block the signal.

The Hands Free Phone system is operated in one of two ways: actively or passively. Active operation begins with the vehicle operator pressing a push button in the EVIC switch pod on the face of the left horizontal spoke of the steering wheel. The Uconnect® Voice Recognition (VR ) button is pressed for hands free voice command access to available features other than the phone, or the Uconnect® Phone (Phone is identified by a phone handset icon) button is pressed for hands free phone access.

The VR or Phone button press provides a resistor multiplexed input to the Local Interface Network (LIN) slave node integral to the EVIC switch pod. The LIN slave node sends an electronic switch press message to the LIN master node integral to the microcontroller of the BCM. The BCM is also a gateway to the CAN-IHS data bus and relays the message over the CAN-IHS data bus to the radio.

When the radio receives the electronic switch press message, the radio suppresses any current audio output and issues an audible beep to indicate that the VR hardware is prepared to receive a voice command. Part of the Uconnect® Hands Free Phone system hardware includes the VR microphone integral to the roof lamp unit in the headliner centered between the sun visors near the windshield. The microphone provides a hardwired input of voice commands to the VR engine within the radio, and the ASR software converts that input into an electronic instruction message broadcast over the CAN-IHS data bus to invoke the appropriate system response. If no appropriate voice command is received within a few seconds following the audible beep , the system will provide an audible verbal output listing a menu of the available Voice Recognition options.

Passive operation begins when an incoming cellular call is received. If the Bluetooth® phone is Short Message Service (SMS) text message capable and compatible with the Uconnect® system (see the Uconnect® web site), passive operation will also begin when an SMS text message is received. The call or SMS text message is relayed to the Bluetooth® transceiver embedded within the radio. The Bluetooth® transceiver then instructs the radio to announce the incoming call or message. The vehicle operator presses the Uconnect® Phone button in the steering wheel switch pod or the soft button that will appear in the radio display to accept the call or to accept the message.

The Bluetooth® transceiver connects the voices of the two phone parties using outputs through the audio system speakers and inputs through the Uconnect® hands free microphone. In the case of a text message, the Bluetooth® transceiver sends the message to the VR hardware and the ASR software converts the message from text to voice and plays it through the audio system speakers.

If the radio integrates the optional High-level Telematic Module (HTM), the text message can then be replied to by pressing the Uconnect® VR button and giving an SMS voice command to select from several predetermined short text phrase responses. If the radio does not have the HTM, it can receive and display SMS text messages, but it is not equipped to reply to text messages.

The Hands Free Phone system operates on battery current received through a fused B(+) circuit, but also monitors the ignition status through electronic messages received over the CAN-IHS data bus. If a call is in progress when the status of the ignition transitions to OFF, the system will continue to operate until the call has been completed.

The radio receives electronic message inputs over the CAN-IHS data bus related to the Hands Free Phone system. The radio is also connected to the CAN-Chassis data bus; however, the radio is not a CAN gateway. All electronic message outputs of the radio are carried over the CAN-IHS data bus. When the radio monitors a problem in any of the audio system circuits and components, or in any of the Bluetooth® transceiver circuits, it stores a fault code or Diagnostic Trouble Code (DTC) in its memory circuit.