Land Rover Defender: Anti-Theft - Passive - Operation

PASSIVE START SYSTEM

The RFA prompts each of the internal LF antennas to output a signal. When the smart key is in the passenger compartment, the smart key detects the LF signals. The smart key responds with a data identification signal back to the RF receiver. The RF receiver sends the data identification signals to the RFA.

In addition the RFA sends a separate challenge, through the passive entry transceivers to the smart key. The RFA sends this data to authenticate and obtain the smart key position with accuracy.

When the data received matches that stored in the RFA, the RFA continues the passive start process by communicating a 'smart key valid' signal. The valid signal is received by the BCM/ GWM through the HS CAN body systems bus.

The BCM/ GWM receives the authorization and confirms the response with an internal calculation. The BCM/ GWM passes coded data to the IPC on the HS CAN Human Machine Interface (HMI) systems bus. Upon confirmation from the IPC, Power Mode 6 (ignition ON) is enabled.

The BCM/ GWM exchanges encrypted data with the Electric Steering Column Lock Control Module (VIM) mechanism.

The data authorizes the unlocking of the steering column. The IPC only provides a ground for the VIM motor. The BCM / GWM then sends a mobilization signal to the PCM.

The BCM/ GWM enables the fuel pump relay which provides a startup battery voltage supply to the Fuel Pump Driver Module (FPDM).

When the RFA fails to locate the smart key, a message is displayed in the IPC message center. The message is 'Place Smart Key as shown, and press start button'.

The keyless start backup process must be used to mobilize and start the vehicle.

PASSIVE START BACKUP

When the vehicle is unlocked with the emergency key or the vehicle does not detect a smart key. Using the passive start backup procedure is then necessary for the following:

• Disarm the alarm
• Start the engine.

The following passive start backup process must be followed in this event:

• Pressing the ignition switch when the RFA fails to locate the smart key. 'Place Smart Key as shown, and press start button' appears in the IPC message center.
• For vehicles with a manual or powered steering column, position the smart key under the lower steering column cowl. The switches on the smart key must face outwards.
• Pressing the ignition switch with the brake pedal pressed to start the engine.

NOTE: When the 'Place Smart Key as shown, and press start button' message is no longer displayed (only displayed for 10 seconds), the sequence has to be repeated.

The process bypasses the data exchange between the RFA and the BCM/ GWM. The process is an inductive process and operates even if the battery in the smart key is discharged. A transponder within the smart key is detected by the IAU. The IAU communicates this code with the BCM/ GWM through a LIN connection. The BCM/ GWM then initiates the vehicle start process in the normal manner.

ULTRA WIDE BAND OPERATION

With the introduction of ultra wide band technology, recognizing the position of the smart key requires 2 pieces of distance information. The 2 passive entry transceivers are located in the headliner, 1 at the front and 1 at the rear. The passive entry transceivers enable full coverage inside and outside of the vehicle.

The following process takes place to validate the smart key:

• The RFA receives a door lock/unlock request.
• When the RFA receives the door lock/unlock request, it sends out the challenge data through the LF antenna to the smart key. The data is sent at 125 kHz.
• The smart key responds to the LF signal, processing the received message and replies to the vehicle using a separate RF channel. Depending on market the RF channels are 433 MHz or 315 MHz.
• This response is received by the RF receiver.

In addition the RFA sends a separate challenge, through the passive entry transceivers to the smart key. The RFA sends this data to authenticate and obtain the smart key position with accuracy, using the following process:

• The challenge data is sent from the RFA through a LIN to the passive entry transceivers.
• The passive entry transceivers process and transmit the data, through a separate RF signal, at 3.99 GHz (4.5 GHz in China) to the smart key.
• On receipt of the signal the smart key responds with an authentication message back to the passive entry transceivers. The smart key responds by a RF signal through the LIN connection.

When the smart key is validated the system operates normally.

LOW FREQUENCY ZONES

The message contained in the beacon signals varies based on each transmitter zone. For example, the message varies based on when the zone is:

• Inside or outside the vehicle.
• The driver side, passenger side or the loadspace.

The capability allows the smart key to send specific answers, triggering actions such as opening the passenger door or starting the engine.

DIAGNOSTICS

The BCM/ GWM records any Diagnostic Trouble Code(s) (DTC) and related data. The DTC and related data are read using the Jaguar Land Rover (JLR) approved diagnostic equipment.

The JLR approved diagnostic equipment enables certain components to be activated and also read live data.

CONTROL DIAGRAM

CONTROL DIAGRAM - 1 OF 2 - PASSIVE START

A = HARDWIRED: O = LIN: AX = FLEXRAY: AZ = HS CAN BODY SYSTEM BUS: BA = HS CAN HMI SYSTEM BUS.

1. BCM/ GWM
2. RFA
3. IPC
4. PCM
5. VIM
6. Fuel pump relay
7. PCM
8. IPC
9. Ground
10. Power supply
11. Transmission Control Switch (TCS)
12. Ignition switch
13. IAU

CONTROL DIAGRAM - 2 OF 2 - SMART KEY RECOGNITION AND DETECTION

A = HARDWIRED: F = RF TRANSMISSION: O = LIN: W = LF TRANSMISSION: AZ = HS CAN BODY SYSTEMS BUS.

1. RFA
2. BCM/ GWM
3. LF antenna (quantity 6)
4. Smart key
5. RF receiver
6. Passive entry transceiver - Front
7. Passive entry transceiver - Rear
8. Lock/unlock request - Door handle
9. IAU

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