GM Service Manual Online
For 1990-2009 cars only

Remote Function Actuation (RFA) System


Object Number: 515892  Size: MF

The Remote Function Actuation (RFA) system performs the following functions:

    • Transmitter remote control of various vehicle systems without physical contact of any switches on the vehicle
       - Lock and unlock the both doors
       - Turn the panic alarm ON or OFF
       - Arm or disarm the theft deterrent system
       - Hatch or trunk release
       - Vehicle lamp control (approach, courtesy)
       - Activate memory features (with memory option only)
    • Tire Pressure Monitoring (TPM) system functions. Refer to Tire Pressure Monitor System Description .

The RFA system consists of a transmitter located on the operator's key fob, and a receiver (with an integral antenna) located over the LR wheelhouse. The receiver is capable of recognizing three transmitter codes. The RFA system does not directly control its functions, but relies on other systems in order to perform the transmitter's commands. The receiver receives and transmits various information from the following systems in order to perform specific functions.

    • The Body Control Module (BCM) -- in order to provide Theft Deterrent, hatch release, horn, and vehicle illumination control features.
    • The Door Control Modules (DCM) -- in order to provide all door lock and memory mirror functions.
    • The Seat Control Module (SCM) -- in order to provide memory seat features.
    • The Instrument Panel Cluster (IPC) -- in order to provide RFA system programming, display and vehicle personalization functions.

When the RFA system receives a command from a transmitter, a message is sent via the serial data line to the system module capable of performing the needed function.

The RFA system is intended to be used as a supplementary to the vehicles conventionally operated lock/unlock system. It is not intended to replace, but should be used in conjunction with the door lock key. The system could disable due to radio frequency interference or a low transmitter battery. Therefore, always maintain vehicle access with a door key.

RFA System Functions

The RFA system consists of the following major components:

    • A low power signal transmitter (key fob)
    • A receiver with integrated antenna

The RFA system allows the user to lock or unlock the vehicle through a transmitter located on the user's key fob. The RFA transmitter is a battery powered, water resistant, radio frequency signal generator. The RFA transmitter consists of four manual buttons. The operation of the keyless entry system is described below:

Manual Features

    • Door UNLOCK Button -- with a programmed transmitter in range, unlocks the driver and passenger doors (depending on personalized options selected), disarms the theft deterrent system, activates illumination and memory features (if equipped).
    • Door LOCK Button -- with a programmed transmitter in range, locks the driver and passenger doors, arms the theft deterrent system.
    • HATCH Button -- with a programmed transmitter in range/trans in park (Auto trans) parking brake applied (manual trans), releases the hatch or trunk, disarms the theft deterrent system.
    • PANIC Button -- with a programmed transmitter in range (key out of the ignition), activates the horns when pressed.

When the transmitter manual UNLOCK button is pressed once, the transmitter sends an identification code to the receiver to unlock the driver door. The receiver sends the message to the driver DCM on the serial data line to unlock the driver door. The DCM will then unlock the driver door. The BCM also responds to this message and disarms the theft deterrent system. The BCM will also activate the courtesy lamps if the ambient light is low. If the UNLOCK button is pressed again within 10 seconds, the receiver sends a second message to the passenger DCM to unlock the passenger door. The DCM then unlocks the passenger door.

When the transmitter manual LOCK button is pressed, the transmitter sends an identification code to the receiver to lock both doors. The receiver sends the message to both of the DCMs on the serial data line to lock both doors. Both DCM will then lock both doors. The BCM also responds to this message and arms the theft deterrent system.

When the manual HATCH button is pressed, the transmitter sends an identification code to the receiver to release the hatch or trunk. The receiver sends the message through the serial data line to the BCM. The BCM then disarms the theft deterrent system and activates the hatch or trunk release relay, and the hatch or trunk opens.

When the manual PANIC button is pressed, the transmitter sends an identification code to the receiver to activate the panic mode. The receiver sends the message through the serial data line to the BCM. The BCM activates the horn relay or flashes the lamps (depending on selected personalized options) for 90 seconds or until the panic button is pressed again.

Personalization

The user of the RFA system, will be able to choose from the following personalized options:

    • Whether or not the passenger door unlocks with the driver door.
    • Approach lights illuminate with UNLOCK command (Manual button press only).

System personalization can only be accessed through the DIC by performing the following procedure:

  1. Press the RESET button in order to clear any IPC warnings.
  2. Press the OPTIONS button on the DIC until the IPC displays PASSIVE UNLK.
  3. Using the RESET button, select PASSIVE UNLK DRIVER or PASSIVE UNLK BOTH.
  4. Press the OPTIONS button on the DIC until APPROACH LIGHTS is displayed.
  5. Using the RESET button, select ON or OFF.

Arming/Disarming Theft Deterrent

When the RFA system sends a lock command on the serial data line to the DCMs, the DCMs will lock the doors and the BCM will arm the theft deterrent system. The BCM then turns off the courtesy lamps and sound the horn, indicating that the theft deterrent system is armed. Whenever the doors are unlocked or the hatch is release, the BCM disarms the theft deterrent system.

To send a DISARM theft deterrent message to the BCM, the RFA system must see the following conditions:

    • A valid transmitter is in range.
    • The key is not in the ignition.
    • The receiver has identified an active unlock command or the hatch or trunk release command from a valid transmitter.

To send an ARM theft deterrent message to the BCM, the RFA system must see the following conditions:

    • Transmitter LOCK button has been pressed.
    • The key is not in the ignition.

RFA Operational Range

Operational range varies with the orientation of the transmitter. For best performance, hold the transmitter vertically, with the buttons facing you and the bottom cover of the transmitter towards the vehicle. As battery life decreases, so does the maximum operational range of the RFA transmitter. In most cases, the transmitter battery should only be replaced when the operational range has severely decreased. If the transmitter range decreases or the transmitter does not operate, test for the following conditions:

    • Test if battery replacement is necessary
    • Test for proper range (Rainy or snowy weather decreases range)
    • Test for obstructions (other vehicles or objects will decrease range)
    • Electrical interference (cellular phones, power lines, radio towers, garage door openers, etc.)
    • The transmitter is not programmed or synchronized to the vehicle

RFA Range Location


Object Number: 65707  Size: MH

Range

Transmitter Location

15.2-30.4 m

(50-100 ft)

A, B, C