Ignition Key

IGNITION KEY





The ignition key is of the folding blade type, which is released from the stowed position by pushing the key release button on the key head. The key head is a sealed unit that contains a Printed Circuit Board (PCB) and a rechargeable battery. The PCB incorporates the electronics that generate RF signals for remote operation of the CLS and personalized feature. The PCB also incorporates the transponder for engine immobilization.

The battery is non serviceable, and recharges while the engine is running. If the battery charge is low, the remote operating range is reduced. The nominal life of the battery is approximately 14 years.

The key head has three buttons for operation of the CLS and the personalized feature, as follows:
^ A lock button, for locking and superlocking of the vehicle.
^ An unlock button, for unlocking the vehicle.
^ A personal button, for operating the personalized feature, which can be programmed to trigger a panic alarm,operate the headlamp courtesy delay or remotely raise and lower the suspension. Programming the personalized feature with a different function automatically overwrites the previous function. The personalized feature is programmed with the key removed from the ignition switch, as follows:
^ Panic alarm. Push and hold the personal button, then push and hold the hazard flasher switch. After a confirmation chime sounds on the instrument cluster speaker, release the personal button and the hazard flasher switch. Push and release the hazard flasher switch again, to cancel the hazard flashers.
^ Headlamp courtesy delay. Push and hold the personal button, then activate the main beam flash switch (pull switch towards you). After a confirmation chime sounds on the instrument cluster speaker, release the personal button and the main beam flash switch.
^ Suspension. Push and hold the personal button, then use the air suspension switch to select a different ride height. After a confirmation chime sounds on the instrument cluster speaker, release the personal button and the air suspension switch. Programming the personal button to operate the air suspension must take place within 60 seconds of turning the ignition off. The air suspension switch position is relayed to the CJB on the CAN systems, which power down 60 seconds after the ignition is switched off.

The ignition keys are externally identical for all markets, but differ in the frequency and power at which the RF transmitter in the key head operates. The RF transmitters operate at 433 MHz, 315 MHz or 315 MHz low power.

Each ignition key has a unique identification which is determined by the transponder in the key head. Every RF signal from the ignition key contains the identification code and a rolling code. The CJB checks the codes and only responds if the signal is from a valid ignition key. During vehicle production, the identification code of each ignition key supplied with the vehicle is programmed into the CJB, and the rolling codes in the ignition key and the CJB are synchronized. A total of 30 'slots' are available in the CJB software to allow for replacement and additional ignition keys. In service, T4 can be used to communicate with the CJB for the following:
^ Identify ignition key allocation within the CJB.
^ Enable new ignition keys.
^ Disable ignition keys.
^ Re-enable a previously disabled ignition key.

If the vehicle lockset is replaced, the keys supplied with the new lockset must be enabled and the old keys disabled.

If the rolling code of an ignition key loses synchronisation with the CJB, the remote operating functions will cease to operate. Synchronisation can be restored by starting the engine with the unsynchronized ignition key and allowing the engine to run for a minimum of 6 minutes.