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POWER LOCKSA power lock system is optional factory-installed equipment on this model. The power lock system is offered only on models that are also equipped with power windows. On vehicles equipped with power locks, the power lock motors are controlled by a microprocessor-based Central Timer Module (CTM). The CTM is used to provide many electronic features and conveniences that are not possible with a conventional hard wired power lock system. The CTM microprocessor is able to control power lock system operation based upon the CTM programming and electronic message inputs received from other electronic modules in the vehicle over the Programmable Communications Interface (PCI) data bus network, Radio Frequency (RF) inputs received from the optional Remote Keyless Entry (RKE) system transmitters, as well as many hard wired inputs.
The power lock system includes the following major components:
- Central Timer Module - The Central Timer Module (CTM) is located on the left cowl side inner panel under the driver side outboard end of the instrument panel. The CTM contains a microprocessor and software that allow it to provide the many electronic functions and features not available with conventional hard wired power lock systems.
- Driver Door Module - A power lock switch is integral to the driver door module unit located near the forward end of the arm rest on the driver side front door trim panel and allows the power lock system to be operated by the driver.
- Power Lock Motors - A reversible electric motor integral to the door latch of each door locks or unlocks the latches when provided with the appropriate electrical inputs.
- Power Lock Switch - An individual power lock switch is secured to a switch bezel near the forward end of the arm rest on the passenger side front door trim panel and allows the power lock system to be operated by the front seat passenger.
On those models equipped with the optional Vehicle Theft Security System (VTSS), the power lock system also includes the following components:
- Door Cylinder Lock Switches - A resistor-multiplexed switch located on the back of each front door lock cylinder allows the power door lock system to be operated using a key inserted in either the driver or passenger front door lock cylinder.
The power lock system allows all doors to be locked or unlocked electrically by operating the power lock switch on either front door trim panel. The power locks can also be operated using the RKE transmitter, and on vehicles that are equipped with the optional Vehicle Theft Security System (VTSS) the power locks can also be operated using a key in either front door lock cylinder. If certain features of the power lock system have been electronically enabled, the power locks may also be operated automatically by the Central Timer Module (CTM) based upon various other inputs.
Some of the additional features of the power lock system in this model include:
- Automatic Door Lock - If enabled, the CTM will automatically lock the doors when it receives a message from the Powertrain Control Module (PCM) indicating that the vehicle speed is about 24 km/h (15 mph) or greater.
The CTM also monitors the door ajar switches, and will not activate the automatic door lock feature until all doors have been closed for at least five seconds. If this feature is enabled and a door is opened after the vehicle is moving at 24 km/h (15 mph) or greater, the CTM will lock the doors again five seconds after all doors are again closed.
- Central Locking - Vehicles equipped with the optional VTSS also have a resistor-multiplexed door cylinder lock switch mounted to the back of the lock cylinder within each front door. The CTM continually monitors the input from these switches to provide the central locking/unlocking feature. The CTM will automatically lock or unlock all doors when either front door is locked or unlocked using a key.
- Door Lock Inhibit - The CTM receives inputs from the key-in ignition switch, the headlamp switch, and the door ajar switches. The logic within the CTM allows it to monitor these inputs to provide a door lock inhibit feature. The door lock inhibit feature prevents the power lock system from being energized with a power lock switch input if the driver door is open with the headlamps on or the key still in the ignition switch. However, the locks can still be operated with the manual door lock button or with a key in the door lock cylinder, and the power locks will still operate using the RKE transmitter while the driver door is open with the headlamps on or a key in the ignition.
- Enhanced Accident Response - The CTM provides an enhanced accident response feature. This feature uses electronic message inputs received by the CTM from the Airbag Control Module (ACM) to determine when an airbag has been deployed. The CTM also monitors the state of the power lock system and the vehicle speed messages from the PCM in order to provide this feature. If an airbag has been deployed and the vehicle has stopped moving, the CTM will automatically unlock the doors, prevent the doors from being locked, and turn on the courtesy lamps inside the vehicle. Of course, these responses are dependent upon a functional battery and electrical circuitry following the impact.
The power lock system operates on battery current received through a fused B(+) circuit from a fuse in the Junction Block (JB) so that the system remains functional, regardless of the ignition switch position. Also, each power lock switch operates independent of the other and receives ground through a single wire take out of the body wire harness with an eyelet terminal connector that is secured by a ground screw to the lower left B-pillar. The power lock switches direct a resistor multiplexed ground Lock or Unlock request signal to the CTM, and the CTM energizes internal relays to direct the appropriate battery current and ground feeds to the individual power lock motors.
Many of the electronic features in the vehicle controlled or supported by the CTM are programmable using the DRB III scan tool. If any of the CTM hardware components are damaged or faulty, the entire CTM unit must be replaced. The power lock system components and the hard wired inputs or outputs of the CTM can be diagnosed using conventional diagnostic tools and methods; however, for diagnosis of the CTM or the PCI data bus, the use of a DRB III scan tool is required. Refer to the appropriate diagnostic information.
The power lock system allows all doors to be locked or unlocked electrically by operating the power lock switch on either front door trim panel. The power locks can also be operated using the RKE transmitter, and on vehicles that are equipped with the optional Vehicle Theft Security System VTSS) the power locks can also be operated using a key in either front door or the liftgate lock cylinder. If certain features of the power lock system have been electronically enabled, the power locks may also be operated automatically by the Central Timer Module (CTM) based upon various other inputs. Those features and their inputs are:
- Automatic Door Lock - If enabled, the CTM will automatically lock the doors when it receives a message from the Powertrain Control Module (PCM) indicating that the vehicle speed is about 24 km/h (15 mph) or greater. The CTM also monitors the door ajar switches, and will not activate the automatic door lock feature until all doors have been closed for at least five seconds. If this feature is enabled and a door is opened after the vehicle is moving at 24 km/h (15 mph) or greater, the CTM will lock the doors again five seconds after all doors are again closed.
- Central Locking - Vehicles equipped with the optional VTSS also have a resistor-multiplexed door cylinder lock switch mounted to the back of the lock cylinder within each front door. The CTM continually monitors the input from these switches to provide the central locking/unlocking feature. The CTM will automatically lock or unlock all doors when either front door is locked or unlocked using a key
- Door Lock Inhibit - The CTM receives inputs from the key-in ignition switch, the headlamp switch, and the door ajar switches. The logic within the CTM allows it to monitor these inputs to provide a door lock inhibit feature. The door lock inhibit feature prevents the power lock system from being energized with a power lock switch input if the driver door is open with the headlamps ON or the key still in the ignition switch. However, the locks can still be operated with the manual door lock button or with a key in the door lock cylinder, and the power locks will still operate using the RKE transmitter while the driver door is open with the headlamps ON or a key in the ignition.
- Enhanced Accident Response - The CTM provides an enhanced accident response feature. This feature uses electronic message inputs received by the CTM from the Airbag Control Module (ACM) to determine when an airbag has been deployed. The CTM also monitors the state of the power lock system and the vehicle speed messages from the PCM in order to provide this feature. If an airbag has been deployed and the vehicle has stopped moving, the CTM will automatically unlock the doors, prevent the doors from being locked, and turn ON the courtesy lamps inside the vehicle. Of course, these responses are dependent upon a functional battery and electrical circuitry following the impact.
The power lock system operates on battery current received through a fused B(+) circuit from a fuse in the Junction Block (JB) so that the system remains functional, regardless of the ignition switch position. Also, each power lock switch operates independent of the other and receives ground through a single wire take out of the body wire harness with an eyelet terminal connector that is secured by a ground screw to the lower left B-pillar. The power lock switches direct a resistor multiplexed ground Lock or Unlock request signal to the CTM, and the CTM energizes internal relays to direct the appropriate battery current and ground feeds to the individual power lock motors.
REMOTE KEYLESS ENTRY SYSTEM
A Remote Keyless Entry (RKE) system is on this model when it is equipped with the optional power lock system. The RKE system is a Radio Frequency (RF) system that allows the remote operation of the power lock system and, if the vehicle is so equipped, the Vehicle Theft Security System (VTSS). (Refer to VEHICLE THEFT SECURITY - DESCRIPTION). The RKE system includes the following major components, which are described in further detail:
- Central Timer Module - The Central Timer Module (CTM) is located on the left cowl side inner panel under the driver side outboard end of the instrument panel. The CTM contains a microprocessor, an RF receiver, and the software that allow it to provide the many electronic functions and features of the RKE system.
- Keyless Entry Transmitter - The keyless entry transmitter is a small, battery-powered, RF transmitter that is contained within a molded plastic case that is designed to also serve as a convenient key fob.
Some additional features of the RKE system include:
- Driver Door Unlock Only - This is a programmable feature which allows the option of having a single press of the RKE transmitter Unlock button unlock only the driver door, or all doors. If the driver door only option is selected, a second press of the Unlock button will unlock the remaining doors.
- Horn Chirp - This feature provides a short, sharp chirp of the vehicle horn to give an audible confirmation that a valid Lock signal has been received from the RKE transmitter. This feature can be enabled or disabled and, if enabled, one of two optional horn chirp durations (20 or 40 milliseconds) can also be selected.
- Illuminated Entry - This feature turns ON the cargo lamp and courtesy lamps in the vehicle for a timed interval (about 30 seconds) each time a valid Unlock signal has been received from the RKE transmitter.
- Optical Chirp - This feature provides a flash of the vehicle park lamps to give an optical confirmation that a valid Lock or Unlock signal has been received from the RKE transmitter. The lamps flash once for a Lock signal, and twice for an Unlock signal. This feature can be enabled or disabled.
- Panic Mode - This feature allows the vehicle operator to cause the vehicle horn to pulse and headlights to flash for about three minutes, and the courtesy lamps to illuminate for about 30 seconds by depressing a Panic button on the RKE transmitter. Pressing the Panic button a second time will cancel the Panic mode. A vehicle speed of about 24 km/h (15 mph) will also cancel the panic mode.
On vehicles with the Remote Keyless Entry (RKE) system, the power locks can be operated remotely using the RKE transmitter. If the vehicle is so equipped, the RKE transmitter also arms and disarms the factory-installed Vehicle Theft Security System (VTSS). Three small, recessed buttons on the outside of the transmitter case labelled Lock, Unlock, and Panic allow the user to choose the function that is desired. The RKE transmitter then sends the appropriate Radio Frequency (RF) signal. An RF receiver that is integral to the Central Timer Module (CTM) receives the transmitted signal, which then uses its internal electronic programming to determine whether the received signal is valid and what function has been requested. If the signal is valid, the CTM then provides the programmed features.
Besides operating the power lock system and arming or disarming the VTSS, the RKE system also controls the following features:
- Driver Door Unlock Only - If this feature is enabled, the CTM unlocks only the driver side front door upon receipt of a first valid Unlock signal through a separate internal relay and control outputs to the driver side front door power lock motor. Then upon receipt of a second valid Unlock signal, the CTM unlocks all of the remaining doors through a separate internal relay and control circuits for those power lock motors.
- Horn Chirp - If this feature is enabled, the CTM provides a horn chirp by internally pulling the control coil of the horn relay to ground through a hard wired circuit output.
- Illuminated Entry - The CTM provides illuminated entry by internally controlling the current flow to the courtesy lamps and cargo lamp in the vehicle through a hard wired output circuit.
- Optical Chirp - If this feature is enabled, the CTM provides flashes of the park lamps by internally pulling the control coil of the park lamp relay to ground through a hard wired circuit output.
- Panic Mode - The CTM provides the horn pulse by internally pulling the control coil of the horn relay through a hard wired circuit output, then flashes the headlamps and illuminates the courtesy lamps through its internal high side control of these circuits. The CTM also monitors the vehicle speed through electronic messages it receives from the Powertrain Control Module (PCM) over the Programmable Communications Interface (PCI) data bus network.
The RKE system operates on battery current received through a fused B(+) circuit from a fuse in the Junction Block (JB) so that the system remains functional, regardless of the ignition switch position. The RKE system can retain the vehicle access codes of up to four RKE transmitters. The transmitter codes are retained in RKE system memory, even if the battery is disconnected. If a transmitter is faulty or is lost, new transmitter vehicle access codes can be programmed into the system using a DRB III scan tool. Refer to the appropriate diagnostic information. Many of the electronic features in the vehicle controlled or supported by the CTM are programmable using the DRB III scan tool. If any of the CTM hardware components are damaged or faulty, the entire CTM unit must be replaced. The hard wired inputs or outputs of the CTM can be diagnosed using conventional diagnostic tools and methods; however, for diagnosis of the CTM or the PCI data bus, the use of a DRB III scan tool is required. Refer to the appropriate diagnostic information.