Keyless Entry: Description and Operation

REMOTE KEYLESS ENTRY SYSTEM
A Radio Frequency (RF) type Remote Keyless Entry (RKE) system is standard factory-installed equipment on this model. The RKE system allows the use of a remote battery-powered radio transmitter to control the power lock system. The RKE receiver operates on non-switched battery current through a fuse in the Power Distribution Center (PDC), so that the system remains operational, regardless of the ignition switch position.

In addition to Lock and Unlock buttons, the RKE transmitters are also equipped with a Panic button. If the Panic button on the RKE transmitter is depressed, the horn will sound and the exterior lights will flash on the vehicle for about three minutes, or until the Panic button is depressed a second time. A vehicle speed of about 24 km/h (15 mph) will also cancel the panic event.

The RKE system can also perform other functions on this vehicle. If the vehicle is equipped with the optional Vehicle Theft Security System (VTSS), the RKE transmitter will arm the VTSS when the Lock button is depressed, and disarm the VTSS when the Unlock button is depressed. If the vehicle is equipped with the optional Memory System, each of the two numbered and color-coded RKE transmitters can be used to recall the stored driver side front seat position, both outside power rear view mirror positions, and the radio station presets for the two assigned drivers.

The RKE system includes two transmitters when the vehicle is shipped from the factory, but the system can retain the vehicle access codes of up to four transmitters. The transmitter codes are retained in the RKE receiver memory, even if the battery is disconnected. If an RKE transmitter is faulty or lost, new transmitter vehicle access codes can be programmed into the system using a DRB III scan tool and the appropriate diagnostic information.

This vehicle also offers several customer programmable features, which allows the selection of several optional electronic features to suit individual preferences. Customer programmable feature options affecting the RKE system include:

- Remote Unlock - Allows the option of having only the driver side front door unlock when the RKE transmitter Unlock button is depressed the first time and the remaining doors and the liftgate unlock when the button is depressed a second time, or having all doors and the liftgate unlock upon the first depression of the RKE transmitter Unlock button.
- Remote Linked to Memory - If the vehicle is equipped with the Memory System, this feature allows the option of having the RKE transmitter Unlock button activate the recall of the stored settings, or having the recall function assigned solely to the memory switch on the driver side front door trim panel.
- Sound Horn on Lock - Allows the option of having the horn sound a short chirp as an audible verification that the RKE system received a valid Lock request from the RKE transmitter, or having no audible verification.
- Flash Lights with Lock - Allows the option of having the lights flash as an optical verification that the RKE system received a valid Lock request or Unlock request from the RKE transmitter, or having no optical verification.

This information covers the following components of the RKE system:
- RKE Receiver
- RKE Transmitter

Certain functions and features of the RKE system rely upon resources shared with other electronic modules in the vehicle over the Programmable Communications Interface (PCI) data bus network. The PCI data bus network allows the sharing of sensor information. This helps to reduce wire harness complexity, internal controller hardware, and component sensor current loads. At the same time, this system provides increased reliability, enhanced diagnostics, and allows the addition of many new feature capabilities. For diagnosis of these electronic modules or of the PCI data bus network, the use of a DRB III scan tool and the appropriate diagnostic information are required.

The other electronic modules that may affect RKE system operation are as follows:
- Body Control Module (BCM) - (Refer to BODY CONTROL/CENTRAL TIMER MODULE - DESCRIPTION).
- Driver Door Module (DDM) - (Refer to DOOR MODULE - DESCRIPTION).
- Electronic Vehicle Information Center (EVIC) - (Refer to ELECTRONIC VEHICLE INFO CENTER - DESCRIPTION).
- Passenger Door Module (PDM) - (Refer to DOOR MODULE - DESCRIPTION).
- Powertrain Control Module (PCM) - (Refer to POWERTRAIN CONTROL MODULE - DESCRIPTION).

Hard wired circuitry connects the RKE system components to the electrical system of the vehicle. These hard wired circuits are integral to several wire harnesses, which are routed throughout the vehicle and retained by many different methods. These circuits may be connected to each other, to the vehicle electrical system and to the RKE system components through the use of a combination of soldered splices, splice block connectors, and many different types of wire harness terminal connectors and insulators. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices and grounds.

Combination Flasher
The combination flasher is a smart relay that functions as both the turn signal system and the hazard warning system flasher. The combination flasher contains active electronic Integrated Circuitry (IC) elements. This flasher can be energized by the BCM to flash all of the park/turn signal/front side marker lamps as an optical alert for the RKE panic function and, if the Flash Lights with Lock programmable feature is enabled, as an optical verification for the RKE lock event.

Horn Relay
The horn relay is a electromechanical device that switches battery current to the horn when the horn switch grounds the relay coil. The horn relay is located in the Power Distribution Center (PDC) in the engine compartment. This relay can be energized by the BCM to sound the horns as an audible alert for the RKE panic function and, if the Sound Horn on Lock programmable feature is enabled, as an audible verification for the RKE lock event.

Low Beam Headlamp Relay
The low beam headlamp relay is a electromechanical device that switches battery current to the headlamp low beams when the BCM grounds the relay coil. The low beam headlamp relay is located in the junction block in the passenger compartment. This relay can be energized by the BCM to flash the headlamp low beams as an optical alert for the RKE panic function.

The Passenger Door Module (PDM) contains the RKE system control logic and the RKE receiver. When the RKE receiver recognizes a Lock, Unlock or Panic message from a valid RKE transmitter, the RKE receiver provides that input to the PDM. The PDM circuitry and programming responds by sending the proper messages to the other electronic modules over the Programmable Communications Interface (PCI) data bus.

When an RKE lock message is received, the doors and the liftgate lock, the interior lighting is turned OFF, the horn chirps (if this feature is enabled), the exterior lamps flash (if this feature is enabled) and, if the vehicle is so equipped, the Vehicle Theft Security System (VTSS) is armed. When an RKE unlock message is received, the driver side front door (or all doors and the liftgate if this feature is enabled) unlock, the interior lighting is turned ON and, if the vehicle is so equipped, the VTSS is disarmed. If the vehicle is equipped with the Memory System and the RKE Linked to Memory feature is enabled, the RKE unlock message also recalls the driver seat, outside mirror and radio settings assigned to the RKE transmitter that sent the unlock signal.

When an RKE panic message is received, the driver side front door (or all doors and the liftgate if this feature is enabled) unlock, the interior lighting is turned on and, if the vehicle is so equipped, the VTSS is disarmed. The panic message will also cause the exterior lamps (including the headlights) to flash, and the horn to pulse for about three minutes, or until a second panic message is received. A vehicle speed of about 24 km/h (15 mph) will also cancel the panic event.

See the owner's manual in the vehicle glove box for more information on the features, use and operation of the RKE system.

REMOTE KEYLESS ENTRY
When the lock button on the transmitter is pressed, all locks will lock, illuminated entry will be turned OFF, (providing all doors are closed) and the vehicle theft security system (if equipped) will be armed. When the unlock button on the transmitter is pressed one time, the driver front door will unlock, the illuminated entry will turn ON the courtesy lamps, the vehicle theft security system (if equipped) will be disarmed. When the button is pressed a second time, the other doors will unlock, This feature is programmable to open all doors on one press using the EVIC or the DRB III.

The passenger door module (PDM) contains the RKE receiver. When the PDM receives a valid signal from the RKE transmitter, it will send a signal on the PCI bus to lock or unlock the doors. The RKE transmitter used radio frequency signals to communicate with the RKE receiver. If vehicle is equipped with the memory system, the memory message will be received as to which transmitter sent the signal (1 or 2).

Panic Function
When the panic button on the RKE transmitter is pressed it pulsates the headlamp, hazard lamps and horn relays and actuates the courtesy lamp relay. By pressing the button again the horn and exterior lamps will stop but the courtesy lamps will remain ON until the BCM times them out or the ignition is turned ON. The panic feature is able to be set if the ignition is ON but only if the panic button is pressed prior to the vehicle being started, it will continue for three minutes or until the vehicle has reached a speed of 15 MPH, if not canceled by the operator.