Power Locks: Description and Operation
INTRODUCTIONPower door locks are optional factory-installed equipment on this model. Power windows are included on vehicles equipped with the power door lock option. The Remote Keyless Entry (RKE) system is also an available option on models equipped with power door locks.
POWER LOCK SYSTEM
Two different power lock systems are offered. Both power lock systems include the power lock switches on each door trim panel, and the power lock motors inside each door. On models without the optional Remote Keyless Entry (RKE) system, the power lock switches are hard-wired directly to the power lock motors, and a base version of the Central Timer Module (CTM) is used.
On models with the optional RKE system, a high-line or premium version of the CTM is used. The high-line and premium CTM incorporates the RKE receiver and logic, power lock control circuitry, and power lock and unlock relays. The power lock switches are hard-wired to the CTM, and the CTM controls the hard-wired output to the power lock motors.
The CTM controls the door lock actuator assemblies to handle locking and unlocking with the keyfob or interior switch. There is also a door lock inhibit feature that prevents power locking of the doors if the ignition is OFF and the key is in the ignition. Automatic or rolling locks are included as a DRB programmable feature. If the vehicle is moving approximately 15 mph and approximately 10 degrees of throttle opening is seen by the PCM, (the PCM will send this info to the CTM via the CCD bus) indicating acceleration, the CTM will cycle the lock actuators.
The power lock system allows both doors to be locked or unlocked electrically by operating the switch on either door trim panel. The power lock system operates on non-switched battery current supplied through a fuse in the junction block so that the system remains functional, regardless of the ignition switch position.
Following are general descriptions of the major components in the power lock system. Refer to the owner's manual in the vehicle glove box for more information on the features, use and operation of the power lock system.
REMOTE KEYLESS ENTRY SYSTEM
The Remote Keyless Entry (RKE) system is a radio frequency system that allows the use of a remote battery-powered radio transmitter to control the power lock system. On vehicles with the RKE option, the power locks can be operated by depressing the Lock or Unlock buttons of the RKE transmitter. If the vehicle is so equipped, the RKE transmitter also arms and disarms the factory-installed vehicle theft alarm. Refer to Vehicle Theft/Security Systems for more information on the optional vehicle theft alarm.
The RKE system includes an illuminated entry feature, which turns on the courtesy lamps for a timed interval (about thirty seconds), when the power door locks are unlocked using the RKE transmitter. The RKE system for this vehicle also features a programmable horn chirp and a panic feature. The programmable horn chirp feature allows the enabling or disabling of the horn chirp request that the RKE receiver issues as an audible indication that a valid Lock signal has been received from the RKE transmitter. The panic feature allows the vehicle operator to cause the horn to pulse, the headlights to flash and the courtesy lamps to light for about three minutes by depressing the Panic button on the RKE transmitter.
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 as described in the proper Diagnostic Procedures.
The RKE system consists of the key fob remote radio transmitter and a radio receiver with program logic, which is integral to the high-line or premium versions of the Central Timer Module (CTM).
Following are general descriptions of the major components in the RKE system. Refer to the owner's manual in the vehicle glove box for more information on the features, use and operation of the RKE system.
CENTRAL TIMER MODULE
Three versions of the Central Timer Module (CTM) are available on this vehicle, a base version, a high-line version and a premium version. The base version of the CTM is used on base models of the vehicle. It is also sometimes referred to as the Integrated Electronic Module (IEM). The base version of the CTM combines the functions of a chime/buzzer module, an intermittent wipe module, and an ignition lamp time delay relay in a single unit.
The high-line version of the CTM is used on high-line vehicles. The high-line CTM provides all of the functions of the base version CTM, but also is used to control and integrate many of the additional electronic functions and features included on the high-line models. The premium version of the CTM is the same as the high-line version, but is used only on models equipped with the heated seat option. The high-line and premium versions of the CTM contain a central processing unit and interface with other modules in the vehicle on the Chrysler Collision Detection (CCD) data bus network.
The CCD data bus network allows the sharing of sensor information. This helps to reduce wire harness complexity, reduce internal controller hardware, and reduce component sensor current loads. At the same time, this system provides increased reliability, enhanced diagnostics, and allows the addition of many new feature capabilities.
The high-line or premium CTM controls features and functions of the power lock, illuminated entry, and Remote Keyless Entry (RKE) systems. The high- line CTM receives hard-wired inputs from the power lock switches, CCD message inputs from the Power-train Control Module (PCM) and Airbag Control Module (ACM), and coded radio frequency inputs from the RKE transmitters. In response to those and many other inputs, the internal programming of the CTM sends the proper outputs to control the power lock motors, the headlamp (or security) and horn relays, and the courtesy lamps.
Some of the features and functions of the power lock, illuminated entry and RKE systems made possible because of the communication of the CTM on the CCD data bus network include:
- A door-lock inhibit feature which prevents the power lock system from being energized with a power door lock switch if the key is in the ignition and/or the headlamps are on. However, the locks can still be operated manually, with a key, or energized with the RKE transmitter.
- A Panic Mode feature which can provide additional personal security and protection. When the Panic button on the RKE transmitter is depressed the vehicle horn will pulse, the headlights will flash, and the interior lights will illuminate on the vehicle for about three minutes, or until the Panic button is depressed a second time. A vehicle speed of about 24 kilometers-per-hour (15 miles-per-hour) will also cancel the panic mode.
- A central locking feature. Central locking allows both doors on the vehicle to be locked when a key is used in either front door lock cylinder to lock either front door. Similarly, central locking will also unlock both front doors when the key is rapidly cycled twice to the unlock position in either front door lock cylinder. This feature uses inputs from the two door lock cylinder switches, which are components of the VTSS. Refer to Vehicle Theft Security System for more information on the door lock cylinder switches.
- An enhanced accident response feature will unlock both doors, then prevent the power door locks from locking the doors for a predetermined time interval, after receiving a CCD message from the ACM indicating a frontal impact of the vehicle requiring airbag deployment. This feature will also turn on the courtesy lamps ten seconds after receiving the ACM deployment message, if the CCD vehicle speed message from the PCM indicates that the vehicle is not moving. Of course, these responses are dependent upon functional battery power and wiring circuitry following the impact.
Rolling door locks is a programmable feature of the power lock system. This feature will automatically lock all of the doors after the vehicle reaches a speed of about 24 kilometers-per-hour (15 miles-per-hour) or greater. This feature will also lock the doors if a door is opened, then closed again, at any speed above 24 kilometers-per-hour (15 miles-per-hour).
A programmable feature of the RKE system is the enabling or disabling of the horn chirp following activation of the RKE Lock function. This feature can be enabled or disabled and, if enabled, the horn chirp duration (twenty or forty milliseconds) can be selected.
All versions of the CTM are mounted under the driver side end of the instrument panel, inboard of the instrument panel steering column opening. Refer to Central Timer Module in the Removal and Installation of Instrument Panel Systems for the service procedures.
The programmable features of the CTM can be enabled or disabled using the DRB III scan tool as described in the proper Diagnostic Procedures. Refer to Central Timer Module in the Diagnosis and Testing of for diagnosis of the base version of the CTM. For diagnosis of the high-line or premium version of the CTM or of the CCD data bus, a DRB III scan tool and the proper Diagnostic Procedures are recommended. The CTM cannot be repaired and, if faulty or damaged, it must be replaced.
POWER LOCK SWITCH
The power locks can be controlled by a two-way switch integral to the power window and lock switch and bezel unit on the trim panel of each front door. A Light-Emitting Diode (LED) in the paddle of each switch is illuminated whenever the ignition switch is in the ON position.
On models with a base version of the Central Timer Module (CTM), the power lock switches are hard-wired to the power lock motors. On models with a highline version of the CTM, the power lock switch controls the battery feeds to the lock and unlock sense inputs of the high-line CTM. The CTM then relays the correct battery and ground feeds to the power lock motors.
The power window and lock switch and bezel unit cannot be repaired and, if faulty or damaged, the entire switch and bezel unit must be replaced.
POWER LOCK MOTOR
In the power lock and Remote Keyless Entry (RKE) systems, the door latch lock mechanisms can be actuated by a reversible electric motor. The power lock motor is integral to the door latch mounted within each door.
On models with a base version of the Central Timer Module (CTM), the power lock motor direction 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 direction is controlled by the battery and ground feeds from the power lock and unlock relays, which are integral to the high-line and premium versions of the CTM.
The power lock motor cannot be repaired and, if faulty or damaged, the entire door latch unit must be replaced.
REMOTE KEYLESS ENTRY TRANSMITTER
The Remote Keyless Entry (RKE) system 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.
Each 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. See Remote Keyless Entry Transmitter Programming for more information.
The 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.
REMOTE KEYLESS ENTRY RECEIVER
The Remote Keyless Entry (RKE) receiver is a radio frequency unit that is integral to the high-line or premium version of the Central Timer Module (CTM). The CTM also contains the program logic and control circuitry for the RKE system. The CTM is mounted under the driver side end of the instrument panel, inboard of the instrument panel steering column opening.
The RKE receiver has a memory function to retain the vehicle access codes of at least one, but no more than four RKE transmitters. The receiver is designed to retain the transmitter codes in memory, even if the battery is disconnected.
The RKE receiver is energized by one of three radio frequency inputs from the RKE transmitter; Unlock, Lock, or Panic. The programming of the CTM responds to these RKE inputs, as well as many other inputs, by sending the proper control outputs to the power lock motors, the courtesy lamp circuit, the horn relay, and the headlamp (or security) relay.
For diagnosis or programming of the RKE receiver within the high-line or premium CTM, a DRB III scan tool and the proper Diagnostic Procedures are recommended. The RKE receiver is only serviced as a unit with the high-line or premium CTM and, if faulty or damaged, the CTM unit must be replaced.
HEADLAMP RELAY
The headlamp (or security) relay is a International Standards Organization (ISO) micro-relay. The terminal designations and functions are the same as a conventional ISO relay. However, the micro-relay terminal orientation (or footprint) is different, current capacity is lower, and the relay case dimensions are smaller than those of the conventional ISO relay.
The headlamp relay is a electromechanical device that switches battery current to the headlamps when the high-line or premium Central Timer Module (CTM) grounds the relay coil. See Headlamp Relay in the Diagnosis and Testing for more information.
The headlamp (or security) relay is located in the Power Distribution Center (PDC), in the engine compartment. Refer to the PDC label for relay identification and location.
The headlamp relay cannot be repaired and, if faulty or damaged, it must be replaced.
HORN RELAY
The horn relay is a International Standards Organization (ISO) micro-relay. The terminal designations and functions are the same as a conventional ISO relay. However, the micro-relay terminal orientation (or footprint) is different, current capacity is lower, and the relay case dimensions are smaller than those of the conventional ISO relay.
The horn relay is a electromechanical device that switches battery current to the horn when the horn switch or when the high-line or premium Central Timer Module (CTM) grounds the relay coil. See Horn Relay in the Diagnosis and Testing for more information.
The horn relay is located in the Power Distribution Center (PDC), in the engine compartment. Refer to the PDC label for relay identification and location.
If a problem is encountered with a continuously sounding horn, it can usually be quickly resolved by removing the horn relay from the PDC until further diagnosis is completed.
The horn relay cannot be repaired and, if faulty or damaged, it must be replaced.