Keyless Entry And Burglar Alarm
Remote Keyless Entry System
The aim of this function is to receive the key fob signal and decode it. There are 4 different data included in the radio frequency frame sent by the RKE to the IPM module:
- Central door lock
- Central door unlock
- Panic function
- Tailgate unlock
Each vehicle can have at most 4 programmed RKE transmitters. The transmitter is physically separated from the key itself (separate device).
Description
The RF signal from the key is received by a special IPM daughter board. This signal (RKE signal) is transmitted to the micro controller where the RKE function is in charge of decoding it.
Lock/Unlock with key
When the key Lock (respectively Unlock) button is pressed, a Lock command (respectively Unlock) is issued for all doors by IPM.
In the following description "all doors" means driver door, assist door, left rear door, right rear door and tailgate.
Central lock/unlock with key is independent of door lock status.
In all cases, when IPM issues lock/unlock command, it does not check monitoring switches to make sure command was successful.
2-Turn Unlock
The 2-turn unlock process divides the unlocking of all doors into 2 steps. The first unlock command unlocks only the driver door, the second one unlocks the assist and rear doors and the tailgate.
Remote Keyless Entry Panic
When the key fob panic button is pressed, the siren and also the horn depending on the country are switched on and the hazard lamps are activated.
Function
IPM
Lock / Unlock
Lock
2 turn Unlock
Unlock
Multiple Lock / Unlock within 500 ms
Panic
Tailgate Unlock
Burglar Alarm system
Alarm
Description
The Burglar Alarm function purpose is to prevent intrusion in the vehicle when it has been locked. Burglar Alarm system is armed after all doors have been closed and locked (by key fob or driver/assist door key cylinder) and key is not inserted in ignition key cylinder.
Once it is armed the system considers an attack as any entrance (doors, hood and tailgate) opened.
For the rest of this document the following terms are used:
All doors: Driver door, Assist door, LH Rear door, RH Rear door, Tailgate
Mech. Key: Driver door key cylinder lock/unlock, Assist door key cylinder key lock/unlock
Entrance: All doors and hood
Functional Diagram
Function
IPM
T1 : 27 sec (-0, + 3 sec)
T2 : 10 sec (-0, + 3 sec)
T3 : 0.5 ± 0.1 sec
FAM
RKE Learning System
Description
This is the procedure for the RKE key learning and synchronization for HM Program.
The IPM and the RF keys are delivered by separated logistic flow and are not linked when they are delivered to the assembly plant.
The learning of the keys must be done in two steps:
- First by learning Fix Code of the Key.
- Second by synchronizing Rolling Code between IPM and key, by the first frame received outside the learning procedure.
The RF transmitter (inside the key) is programmed in supplier line on the base of a 24 bits serialized number, which determines the Identifier and Start code value, insuring that all codes are different.
The learning procedure uses the RF frame emission to transmit the RF code data from the key, and a diagnosis tool to control the procedure (Hi-Scan - using the K line).
This learning can be done on Customer dealers or in the garages.
Functional Diagram
IPM
Example : Learning Process Results for Four Key fobs
RKE Synchronization
Description
Once the learning procedure is finished, the operator has to push RF key button of each learnt key to check keys are operational; a door locking/unlocking action is done as feedback.
This first reception and processing of a rolling code data after the learning procedure is the first synchronization (between key and IPM, from a rolling code point of view).
NOTE:
A key is said "active" (learnt), when it has been learnt by way of a learning procedure.
A key is said "synchronized" (operational), when it has been synchronized after the learning procedure
(i.e. validated by a locking/unlocking action with Scan tool connected)
IPM
