Power Locks: Description and Operation
POWER LOCKSPower Locks System
Two different power lock Systems are offered as optional factory-installed equipment on this model. Both power lock systems are offered only on models that are also equipped with power windows. On models without the optional Remote Keyless Entry (RKE) system, a base version of the Central Timer Module (CTM) is used. In this version of the power lock system, the power lock switches provide the only control over the operation of the power lock motors. On models with the optional RKE system, a high-line or premium version of the CTM is used to provide many electronic features and conveniences that are not possible with the base version CTM. In this power lock system, the power lock motors are controlled by the microprocessor-based high-line or premium version of the CTM based upon the CTM programming and electronic message inputs received from other electronic modules in the vehicle over the Chrysler Collision Detection (CCD) data bus network, Radio Frequency (RF) inputs received from the RKE transmitters, as well as many hard wired inputs.
Both versions of the power lock system include the following major components, which are described in further detail elsewhere:
- Power Lock Motors - A reversible electric motor integral to the door latch of each front door locks or unlocks the front door latch when provided with the appropriate electrical inputs.
- Power Lock Switches - A power lock switch integral to the power window/lock switch unit located near the forward end of the arm rest on each front door trim panel allows the power door lock system to be operated by either the driver or the front seat passenger.
On those models equipped with the optional RKE system, the power lock system also includes the following components, which are described in further detail elsewhere:
- Central Timer Module - The high-line or premium Central Timer Module (CTM) is located under the driver side end of the instrument panel, inboard of the instrument panel steering column opening. The high-line or premium CTM contains a microprocessor and software that allow it to provide the many electronic functions and features not available with base version of the power lock system.
- 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.
Some of the additional features of the power lock system found in vehicles with the RKE system option include:
- Automatic Door Lock - The high-line/premium CTM provides an optional automatic door lock feature (also known as rolling door locks). This is a programmable feature.
- Central Locking - The high-line/premium CTM provides an optional central locking/unlocking feature.
- Door Lock Inhibit - The high-line/premium CTM provides a door lock inhibit feature.
- Enhanced Accident Response - The high-line/premium CTM provides an optional enhanced accident response feature. This is a programmable feature.
Hard wired circuitry connects the power lock 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 power lock 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.
Many of the electronic features in the vehicle controlled or supported by the high-line or premium versions of the CTM are programmable using the DRB III scan tool. In addition, the high-line/premium CTM software is Flash compatible, which means it can be reprogrammed using Flash reprogramming procedures. However, 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 high-line or premium versions of the CTM or the CCD data bus, the use of a DRB III scan tool is required. Refer to the appropriate diagnostic information.
All versions of the power lock system allow both doors to be locked or unlocked electrically by operating the power lock switch on either front door trim panel. On vehicles that are also equipped with the optional Remote Keyless Entry (RKE) system, both doors may also be locked or unlocked using a key in either front door lock cylinder, or by using the RKE transmitter. On vehicles with the RKE system, if certain features have been electronically enabled, the locks may also be operated automatically by the high-line or premium Central Timer Module (CTM) based upon various other inputs. Those features and their inputs are:
- Automatic Door Lock - If enabled, the high-line/premium 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 both doors have been closed for at least five seconds. If this feature is enabled and a door is opened after the vehicle is moving, the CTM will also lock the doors five seconds after both doors are closed.
- Central Locking - Vehicles equipped with a high-line/premium CTM also have a resistor-multiplexed door cylinder lock switch mounted to the back of the door 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 both front doors when either front door is locked or unlocked using a key.
- Door Lock Inhibit - The high-line/premium 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 - If enabled, the high-line/premium 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 the 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.
All versions of the power lock system operate 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, in both versions of the power lock system, each power lock switch receives battery current independent of the other. In vehicles with the base version of the power lock system, the driver side power lock switch receives ground through the body wire harness, A single wire take out of the body wire harness with an eyelet terminal connector is secured by a ground screw to the lower left B-pillar (regular cab, extended cab) or lower left quarter inner panel (quad cab). The passenger side power lock switch receives ground through the driver side power lock switch in the base version of the power lock system. The base version power lock switches direct the appropriate battery current and ground feeds to the power lock motors. In the power lock system for vehicles with the RKE system, the power lock switches direct a battery current Lock or Unlock request signal to the high-line or premium CTM, and the CTM energizes internal relays to direct the appropriate battery current and ground feeds to the power lock motors.
Remote Keyless Entry System
A Remote Keyless Entry (RKE) system is an available option on this model. The Remote Keyless Entry (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 ELECTRICAL/VEHICLE THEFT SECURITY - DESCRIPTION). The RKE system includes the following major components, which are described in further detail elsewhere:
- Central Timer Module - The high-line or premium Central Timer Module (CTM) is located under the driver side end of the instrument panel, inboard of the instrument panel steering column opening. The high-line or premium 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:
- 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 (twenty or forty milliseconds) can also be selected.
- Illuminated Entry - This feature turns on the courtesy lamps in the vehicle for a timed interval (about thirty seconds) each time a valid Unlock signal has been received from the RKE transmitter.
- Panic Mode - This feature allows the vehicle operator to cause the vehicle horn to pulse, the headlights to flash, and the courtesy lamps to illuminate for about three minutes 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 miles-perhour) 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 high-line or premium version of the Central Timer Module (CTM) receives the transmitted signal, 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 provides the programmed features.
Besides operating the power lock system and arming or disarming the VTSS, the RKE system also controls the following features:
- 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 in the vehicle through a hard wired output circuit.
- Panic Mode - The CTM provides the horn pulse and headlight flash by internally pulling the control coils of the horn relay and headlamp relay to ground through hard wired circuit outputs. The CTM controls the current flow to the courtesy lamps in the vehicle through a hard wired output circuit. The CTM also monitors the vehicle speed through electronic messages it receives from the Powertrain Control Module (PCM) over the Chrysler Collision Detection (CCD) 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 high-line or premium versions of the CTM are programmable using the DRB III scan tool. In addition, the high-line/premium CTM software is Flash compatible, which means it can be reprogrammed using Flash reprogramming procedures. However, 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 high-line or premium versions of the CTM or the CCD data bus, the use of a DRB III scan tool is required. Refer to the appropriate diagnostic information.
DOOR CYLINDER LOCK SWITCH
A door cylinder lock switch is snapped onto the back of the key lock cylinder inside each front door of vehicles equipped with a high-line or premium Central Timer Module (CTM). The door cylinder lock switch is a resistor multiplexed momentary switch that is hard wired in series between a body ground and the CTM through the front door wire harness. The door cylinder lock switches are driven by the key lock cylinders and contain three internal resistors. One resistor is used for the neutral switch position, one for the Lock position, and one for the Unlock position.
The door cylinder lock switches cannot be adjusted or repaired and, if faulty or damaged, they must be replaced.
The door cylinder lock switches are actuated by the key lock cylinder when the key is inserted in the lock cylinder and turned to the lock or unlock positions. The door cylinder lock switch closes a path to ground through one of three internal resistors for the Central Timer Module (CTM) when the front door key lock cylinder is in the Lock, Unlock, or Neutral positions. The CTM reads the switch status through an internal pull-up, then uses this information as an input for both power lock system and Vehicle Theft Security System (VTSS) operation.
The door cylinder lock switches and circuits can be diagnosed using conventional diagnostic tools and methods.
POWER LOCK MOTOR
Models equipped with the optional power lock system have a power operated door locking mechanism located within each front door. The lock mechanisms are actuated by a reversible electric power lock motor that is integral to the door latch unit within each front door. A single short pigtail wire with a molded plastic connector insulator connects the door lock motor to the vehicle electrical system through a take out and connector of each front door wire harness.
The power lock motors cannot be adjusted or repaired and, if faulty or damaged, the entire door latch unit must be replaced.
On models with a base version of the Central Timer Module (CTM), the power lock motor is controlled by the battery and ground feeds from the power lock switches. On models with the high-line or premium versions of the CTM, the power lock motor is controlled by the battery and ground feeds from the power lock and unlock relays, which are integral and internal to the high-line and premium versions of the CTM. A positive and negative battery connection to the two motor terminals will cause the power lock motor plunger to move in one direction. Reversing the current through these same two connections will cause the power lock motor plunger to move in the opposite direction.
The power lock motors and circuits can be tested using conventional diagnostic tools and methods.
REMOTE KEYLESS ENTRY TRANSMITTER
The Remote Keyless Entry (RKE) system Radio Frequency (RF) transmitter is equipped with three buttons, labeled Lock, Unlock, and Panic. It is also equipped with a key ring and is designed to serve as a key fob. The operating range of the transmitter radio signal is up to 7 meters (23 feet) from the RKE receiver. The RKE receiver is integral to the high-line or premium Central Timer Module (CTM) in this vehicle.
Each RKE transmitter has a different vehicle access code, which must be programmed into the memory of the RKE receiver in the vehicle in order to operate the RKE system. The RKE receiver can retain the access codes for up to four transmitters in its memory. (Refer to POWER LOCKS/REMOTE KEYLESS ENTRY TRANSMITTER - STANDARD PROCEDURE - RKE TRANSMITTER PROGRAMMING).
The RKE transmitter operates on two Duracell DL2016, Panasonic CR2016 (or equivalent) batteries. Typical battery life is from one to two years. The RKE transmitter cannot be repaired and, if faulty or damaged, it must be replaced.
See the owner's manual in the vehicle glove box for more information on the features, use and operation of the Remote Keyless Entry (RKE) transmitters.
POWER LOCK SWITCH
The power lock system can be controlled by a two- way momentary switch integral to the power window and lock switch and bezel unit on the trim panel of each front door. Each power lock switch is illuminated by a Light-Emitting Diode (LED) that is integral to the switch paddle. The LED of each switch is illuminated whenever the ignition switch is in the ON position.
The power lock switches and their LEDs cannot be adjusted or repaired and, if faulty or damaged, the entire power window and lock switch and bezel unit must be replaced.
On models with a base version of the Central Timer Module (CTM), the power lock switches are hard-wired to the power lock motors. The power lock switch provides the correct battery and ground feeds to the power lock motors to lock or unlock the door latches.
On models with a high-line or premium version of the CTM, the power lock switch controls battery current signals to the lock and unlock sense inputs of the CTM. The CTM then relays the correct battery and ground feeds to the power lock motors to lock or unlock the door latches.