Description And Operation

DESCRIPTION 

Courtesy of CHRYSLER GROUP, LLC

The power lock system can contain the following components:

1.	Refer to REMOTE KEYLESS ENTRY (RKE) .
2.	Refer to INSTRUMENT PANEL CLUSTER .
3.	Refer to UCONNECT® TOUCH SCREEN - RRM .
4.	Refer to POWER LOCK SWITCH .
5.	Refer to SMART HANDLE .
6.	Refer to POWER LOCK MOTOR . Refer to AJAR SWITCH  - Integrated into the latch.
7.	Refer to LOW FREQUENCY ANTENNA .
8.	Refer to FUEL LID MOTOR .
9.	Refer to RADIO FREQUENCY HUB .
10.	Refer to BODY CONTROL MODULE .
11.	Refer to AJAR SWITCH  - Plunger Switch.
12.	Refer to AJAR SWITCH  - Hood Latch.
13.	Refer to ELECTRONIC STEERING LOCK (ESL) .
14.	Refer to KEYLESS IGNITION NODE (KIN) .
-	Refer to HORN .

OPERATION 

Remote Keyless Entry Operation 

The RKE system uses non-switched battery current received through a fused B(+) fuse so that the system remains operational regardless of the ignition switch position. The BCM is the primary RKE system controller as well as the Radio Frequency (RF) RKE receiver. The BCM validates the vehicle access code of each RKE transmitter from which it receives RF signal inputs. It ignores requests from any transmitter for which it has no stored vehicle access code. When the BCM receives an input from a valid transmitter source, it uses internal programming to provide the appropriate hard wired outputs to invoke the proper RKE system features and responses.

The RKE system circuits and transmitter inputs are continually monitored by the BCM. When the BCM monitors a problem in any of the RKE system circuits or transmitters, it stores a DTC in its memory circuit.

Passive Entry System Operation 

In the Passive Entry Keyless Go (PEKG) system the doors are unlocked passively; however, they must still be locked actively after exiting the vehicle using the tactile Lock  button on either front door smart handle. When the system senses a hand approaching the capacitive switch in the door Smart handle pull or detects a button press of the liftgate release switch, it sends out challenge messages through the Low Frequency (LF) antennas to authenticate the presence and location of a valid FOBIK.

The FOBIK responds by sending a Very High Frequency (VHF) message back to the receiver within the RFH. If the RFH determines the FOBIK is valid and that it is located outside the vehicle in the same zone or vicinity as the door handle or liftgate switch being activated, it sends an electronic Unlock Request  message over the Controller Area Network (CAN) data bus to the BCM to automatically unlock and allow entry.

The PEKG system circuits and FOBIK inputs are continually monitored by the software contained within the RFH. When the RFH monitors a problem in any of the PEKG system circuits or FOBIK inputs, it stores a Diagnostic Trouble Code (DTC) in its memory circuit.

Refer to COMPONENT INDEX .

In order to perform a lock or unlock command, the BCM has to detect if a door, trunk or hood is open or closed.

Ajar Switch Status: 

• Driver side door switch: if the door is closed the switch is open; if the door is open the switch is closed
• Passenger side door switch: if the door is closed the switch is open; if the door is open the switch is closed
• Rear door switches: if the doors are closed the switches (left and right) are open; if the doors are open, the switches are closed
• Tailgate switch: if the tailgate is closed, the switch is closed; if the tailgate is open, the switch is open
• Hood switch: if the hood is open the switch is open; if the hood is closed the switch is closed

Refer to COMPONENT INDEX .

Is located behind the instrument panel above the left kick panel

Acts as the central gateway module for the CAN bus

The BCM receives an input from the ajar switches to wake the module.

The door unlocking/locking management strategy is carried out by the BCM which controls the effective status of the locks by means of the signals that arrive from the switches in the locks themselves: in this way, the locking command is only carried out if the doors are properly shut and the locks unlocked; conversely, the unlocking command is only carried out if the locks are locked.

The power lock switch (also known as the door inhibit switch) is hard wired to the BCM.

When the BCM receives an input from the power lock switch, it provides the appropriate hard wired control outputs to energize or de-energize the power lock relays soldered onto its printed circuit board. The relays control the flow of battery current and ground to each of the power lock motors to lock or unlock each of the doors.

The BCM also stores the power lock system customer programmable feature settings received from the circuitry of the IPC. The BCM uses these settings and internal programming along with hard wired and electronic message inputs to determine the proper outputs needed to produce each of the appropriate power lock system features.

The power lock system circuits are continually monitored and controlled by the BCM. When the BCM monitors a problem in any of the power lock system circuits or components, it stores a fault code or Diagnostic Trouble Code (DTC) in its memory circuit.

The movement of the key cylinder on the driver door handle is detected by a switch connected electrically to the BCM. If the vehicle is being manually locked or unlocked using a bladed key inserted into the key cylinder, the BCM acquires the variation of resistance level and actuates the lock/unlock motor accordingly.

Refer to COMPONENT INDEX .

The door lock cylinder is a mechanical device allowing the customer to unlock or lock the vehicle with a bladed key.

Centralized locking or unlocking using a bladed key is available. The movement of the key cylinder on the driver door handle is detected by a switch connected electrically to the BCM. If the vehicle is being manually locked or unlocked using a bladed key inserted into the key cylinder, the BCM acquires the variation of resistance level and actuates the lock/unlock motor accordingly.

Remote and Passive Entry Specific:

In the event that the vehicle is not equipped with PEKG, the BCM receives data signals from the RKE transmitter. These data signal can include the number of button presses, the pressure used during the button press and which button was pressed to determination the requested event. The BCM reads this data to provide the appropriate hard wired outputs to invoke the proper RKE system features and responses.

In the event that the vehicle is not equipped with PEKG, the BCM interprets a rolling code from the RKE transmitter to validate that the transmitter is programmed to the vehicle.

The BCM sends the output for horn activation when a remote request for lock is detected and performed.

The BCM sends a request for the turn signal lamps to flash when a remote request for lock is detected and performed, or deadlocking is activated, or if liftgate unlock or release is detected and performed.

The BCM receives deadlocking requests and commands all of the doors locked and sets the deadlock activation.

The BCM will deactivate the deadlocking on request. Deactivation is always managed in parallel for all doors.

On remote start requests, the BCM performs a central locking command.

Refer to COMPONENT INDEX .

The Electronic Steering Lock (ESL) locks and unlocks the steering column when a valid RKE signal is received by the RFH.

Refer to COMPONENT INDEX .

The fuel lid is managed in parallel with the driver door. As soon as a central lock or unlock command is required, the BCM commands the fuel lid to lock or unlock.

Refer to COMPONENT INDEX .

If the vehicle is equipped with an alarm system or if a lock request is sent using the keyless entry transmitter, the horn is activated to "chirp" by receiving the request from the BCM.

Refer to COMPONENT INDEX .

The LED indicator for the door status is controlled by the IPC.

The illumination request is received by the IPC from the BCM and performed by the IPC.

The BCM is connected via the CAN line to the IPC to which it sends a signal that switches on the "door open" warning light and activates the buzzer to give an acoustic signal.

The instrument panel acquires the door status signal via the CAN and switches on the "doors open" warning light and, at the same time, the information is shown on the display; in addition, if one of the doors is open and the speed of the vehicle exceeds around 4 km/h, an acoustic warning is also emitted.

Using the "Set up Menu" on the instrument panel, you can activate or turn off the auto door lock function. This function allows the automatic locking of the doors to be activated when the speed exceeds 20 km/h (25 mph).

Refer to COMPONENT INDEX .

The KIN in conjunction of the RFH will inhibit door lock with a valid key left inside the vehicle if the button on the Smart Handle is pressed to lock the doors.

Refer to COMPONENT INDEX .

There are 5 LF antennas located on this vehicle:

• Driver rear door
• Passenger rear door
• Center console
• Rear fascia
• Rear cargo area

The LF antennas allow the transmitter within the RFH to communicate with a FOBIK that is located inside the vehicle or, at most, about 0.7 meters (2.5 feet) horizontally in all directions around the outside of the vehicle.

The RFH uses communication through the antenna units to wake up and challenge a FOBIK that is within range in order to authenticate whether that FOBIK is valid (programmed) to the vehicle.

The RFH communication with the FOBIK is on 125 kilohertz using Frequency-Shift Keying (FSK) modulation.

Each antenna unit has two dedicated connections to the RFH. One connection is the LF antenna output circuit, while the other connection Is the LF antenna return circuit. These circuits to each antenna unit are a twisted pair to help reduce the potential for induced electrical interference. The RFH continuously monitors all of the antenna units and will store a Diagnostic Trouble Code (DTC) for any fault that it detects.

Refer to COMPONENT INDEX .

The PEKG system makes use of two door locking buttons on the front door handles, through which car users can request door locking. Inside the handles are capacitive sensors (one per handle) which allow the RFH to determine whether the user's hand is near the inside of the handle.

The RFH detects the vicinity of the key to the vehicle through the vehicles various LF antennas. The key recognition and authentication stage begins when the vehicle user brings their hand towards the inside of the handle. At that moment, the RFH reads the key ID and the secret code stored in it. If the RFH identifies it as the key encoded in its memory, it sends the request to unlock the doors or the driver door only (depending on the setting in the "my car" menu) to the BCM.

The smart door handle provides the status for the unlock sensor, the lock sensor, the handle pull status and an error status to the RFH.

The PLGM provides a hard wired output to the BCM that indicates the liftgate ajar status based on the two switch inputs.

The ajar output will mimic an ajar switch that is typically used in other latches - a switch that is open when the liftgate is closed in the primary position and closed to ground when the liftgate is in any other position.

Refer to COMPONENT INDEX .

All the door locking motors are protected and managed by the BCM.

Inside the actuators are PTC elements in series with their motors. The PTC elements permits thermal protection in the event that the BCM continues to supply current to the motors due to a fault. The resistance of the PTC element increases as its temperature increases, consequently interrupting the electrical circuit.

Refer to COMPONENT INDEX .

The power lock system uses non-switched battery current received through a fused B (+) fuse so that the system remains operational regardless of the ignition switch position.

Both the driver and passenger door lock/unlock switch are able to centrally lock and unlock all door latches.

Both the driver and passenger door lock/unlock switches are disabled if the doors are locked from outside of the vehicle. The switches will be enabled again after an unlock operation is performed from outside of the vehicle or when an authenticated key is recognized at ignition ON  .

Refer to COMPONENT INDEX .

The RFH is located in the rear overhead compartment of the vehicle.

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 data bus.

If the vehicle is equipped with a mechanical key, the RFH only carries out the Tire Pressure Monitor (TPM) functionality. The key ID codes are then stored in the BCM instead.

The RFH is the primary RKE system controller as well as the BCM.

The RFH is hard wired to the vehicle's door handles and multiple LF antennas for purposes of providing PEKG functionality.

The RFH marries itself to the BCM and PCM with an Immobilizer Access Code using the Advanced Encryption Standard (AES) at first key on in the assembly plant. 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 data bus message is sent to BCM to lock or unlock the vehicle by the RFH

Refer to COMPONENT INDEX .

The RKE system transmitter is the battery powered, wireless and portable RF user controller for all of the features of the RKE system.

The RKE transmitter has 3 buttons that allow control of the locking system:

• a button for unlocking the doors
• a button for locking the doors
• a button for releasing the liftgate

The RKE transmitter, when a button is pressed, sends a signal to the BCM indicating what button was pressed, how many times and for how long. The BCM interprets these details to perform the proper requested function.

Refer to COMPONENT INDEX .

The Smart Handle (1) consist of a resistive membrane lock switch (3) which allows the user to actively lock the vehicle. The capacitive switch (2) senses a hand approaching the handle pull to passively unlock the vehicle. The Hall-effect switch (4) senses handle pull movement, a magnet (5) in the cap acts against the hall effect switch. An adaptation algorithm in the logic circuit of each handle can modify the sensitivity of the capacitive switches as well as system responses to the Hall-effect switch inputs to compensate for sensed repeated or continuous actuations.

The Smart Handle has a "play protection", In the event that seven (7) handle activations are made (in a row) where no valid FOB is found, the RFH will stop waking the vehicle on detection of a smart door handle and wait until a FOB is detected. After six hundred (600) wakeups where no FOB is found, the RFH will stop waking the vehicle until a smart door handle is pulled. Near the cap on the Smart Door Handle is a hall switch and a magnet in the cap, when the handle is pulled the circuit is closed and the RHF will send the signal to wake the system. In the event that the magnet or circuit is defective, the system may not see the handle activation and render the PE on that door inoperative. The smart door handle provides an error status. The error status generally means a switch is stuck. Any status with an error shall be ignored by the component handling door handles. The handle pulled status is only used to wake a sleeping door handle.

Each of the PE outside smart door or tailgate handle are powered by and provide a direct input to the Integrated Circuit (IC) of that handle. The IC of each PE outside door handle receives power from the RFH on a signal circuit, and a clean ground from the RFH on a return circuit. The PE handle IC and the RFH communicate with each other by modulating the current in the signal circuit.

The inputs from those three switches and the handle logic circuit allow each handle to send the RFH up to four different signals: Unlock Request, Hall, Lock Request and Error. The RFH determines the system response based upon the inputs it receives from each handle as well as the inputs it receives through the authentication process with each detected key fob.

The RFH detects the vicinity of the key to the vehicle through the vehicles various LF antennas. The key recognition and authentication stage begins when the vehicle user brings their hand towards the inside of the handle. At that moment, the RFH reads the Key Identification (KEY-ID) and the secret code stored in it. If the RFH identifies it as the key encoded in its memory, it sends the request to unlock the doors or the driver door only (depending on the setting in the customer programmable options menu) to the BCM.

The smart handle provides the status for the unlock sensor, the lock sensor, the handle pull status and an error status to the RFH.

The tactile switches are serviced separately from the smart handle.

Refer to COMPONENT INDEX .

The U-Connect touch screen radio can send valid panic, remote start, lock and unlock requests to the BCM. The BCM manages these requests.