Power Locks: Description and Operation
POWER LOCKSPower Locks
A power operated door lock system is available factory-installed equipment on this model. The power lock system allows all of the doors to be locked or unlocked electrically by operating a switch on either front door trim panel. The power lock system receives non-switched battery current through a fuse in the Integrated Power Module (IPM), so that the power locks remain operational, regardless of the ignition switch position.
This vehicle also offers several customer programmable features, which allows the selection of several optional electronic features to suit individual preferences.
The power lock system for this vehicle can also be operated remotely using the available Remote Keyless Entry (RKE) system radio frequency transmitters, if equipped.
Certain functions and features of the power lock system rely upon resources shared with other electronic modules in the vehicle over the Programmable Communications Interface (PCI) data bus network. For proper 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 instrument cluster locks or unlocks the doors when an actuation input signal from a door lock switch or Remote Keyless Entry Module (RKE) is received. The instrument cluster turns on the output drivers and provides a voltage level to the door lock motor for a specified time. All passenger doors can be locked or unlocked using a mechanical button mounted on the door trim panel. The front passenger doors can be locked or unlocked by using the key cylinder.
Automatic Door Locks
The instrument cluster locks the doors automatically when the vehicle is driven beyond the speed of 25.7 Km/h (15 mph), all doors are closed and throttle position exceeds 10 %. If a door is opened the Automatic Door Lock feature shall reset and the Instrument Cluster will lock the doors when the above conditions are met. This feature is programmable by the customer or the DRB III. The rolling door lock feature can be disabled if desired.
Central Locking/Unlocking
The instrument cluster will lock all doors when a cylinder lock switch is activated in the "lock" position. When the instrument cluster receives an unlock command from one of the cylinder lock switches, it will unlock only that door. If the instrument cluster receives a second command within a 5 second period, it will unlock all the remaining doors. The illuminated entry will activate during door unlock.
Enhanced Accident Response
Upon detection of an airbag deployment by way of the PCI bus, the instrument cluster will:
- Immediately disable the power door lock output.
- Unlock all doors by activating the door unlock output for approximately 300 milliseconds.
- After actuating the door unlock output, allow the door lock motors to be activated if the door lock input has been inactive (not erratic) for 2 seconds since the reception of the airbag deployment message.
Remote Keyless Entry
A Radio Frequency (RF) type Remote Keyless Entry (RKE) system is an available factory-installed option on this model. The RKE system allows the use of a remote battery-powered radio transmitter to signal the instrument cluster to actuate the power lock system. The RKE receiver operates on non-switched battery current through a fuse in the Integrated Power Module (IPM), so that the system remains operational, regardless of the ignition switch position.
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 25.7 kilometers-per-hour (15 miles-per-hour) 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.
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 a total of four transmitters. The transmitter codes are retained in the RKE module 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.
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 Sequence - Allows the option of having only the driver side front door unlock when the RKE transmitter Unlock button is depressed the first time. The remaining doors unlock when the button is depressed a second time within 5 seconds of the first unlock press. Another option is having all doors unlock upon the first depression of the RKE transmitter Unlock button.
- 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 and Unlock - Allows the option of having the park lamps 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.
- Programming Additional Transmitters - Allows up to a total of four transmitter vehicle access codes to be stored in the receiver memory.
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. 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.
- LOCK: - Pressing the LOCK button locks all doors, sounds horn (chirp) once if enabled, flashes the park lamps once if enabled, and arms the Vehicle Theft Security System (VTSS), if enabled. The chirp verifies that the RKE module has sent a message to the instrument cluster for door lock operation. If a door has not been closed before pressing the LOCK button, the vehicle may not be secured and the VTSS (if equipped) will not arm until the door is closed.
- UNLOCK: - Pressing the UNLOCK button once will unlock the driver's door first if enabled, flashes the park lamps twice if enabled, activates the illuminated entry system, and disarms the Vehicle Theft Security System (VTSS), if equipped. Pressing the UNLOCK button twice within five seconds will unlock all doors, if driver's door first is enabled.
- PANIC: - Pressing the PANIC button sounds the horns at half second intervals, flashes the exterior lamps, and turns ON the interior lamps. The panic alarm will remain ON for three minutes, or until the PANIC button is actuated again or the vehicle speed exceeds 25.7 Km/h (15 mph) will cancel the panic event.
The Remote Keyless Entry Module is capable of retaining the transmitter Vehicle Access Code(s) in its memory even after vehicle power has been interrupted.
Automatic Door Locks
When the automatic door locks are ENABLED the door locks will lock when the vehicle is moving at about 25.7 Km/h (15 mph), all doors are closed and the accelerator pedal is depressed. This feature can be switched ON or OFF as desired. When the system is DISABLED the door locks will operate normally, but will not lock automatically when the vehicle is rolling. Once the automatic door locks have been actuated, they will not try to lock the doors again until a door is opened.
Door Lock Inhibit
If the key is in the ignition, in any position, and either front door is ajar, the doors can not be locked, but the unlock function still operates. Pressing the RKE lock/unlock button under these conditions will result in a normal lock/unlock activation.
After the key is removed from the ignition switch, or the doors are closed, the power door locks will operate normally
Door Lock Circuit Protection
If the door lock switch is actuated continuously for more than five seconds the instrument cluster will turn the output driver OFF (the instrument cluster would consider the switch stuck). Each lock motor is protected with a Positive Temperature Coefficient device that prevents motor burn out.
DOOR LOCK MOTOR
The lock mechanisms are actuated by a reversible electric motor mounted within each door The power lock motors are integral to the door latch units.
The power lock motors cannot be adjusted or repaired and, if faulty or damaged, the door latch unit must be replaced.
The door lock motors are controlled by the instrument cluster. A positive and negative battery connection to the two motor terminals will cause the motor to move in one direction. Reversing the current will cause the motor to move in the opposite direction.
DRIVER DOOR MODULE
A Driver Door Module (DDM) is used on all models equipped with power locks, power windows, and power mirrors. The DDM houses the following switches:
- Power Lock Switch - The DDM includes a two-way, momentary, resistor multiplexed switch to control the power lock system.
- Power Mirror Selector Switch - A three-position rocker switch in the DDM selects the right or left power mirror for adjustment, or turns the power mirror system Off.
- Power Mirror Adjustment Switches - Four momentary, arrowhead shaped, directional switches allow the driver to adjust the selected power mirror in the Up, Down, Right, or Left directions.
- Power Window Lockout Switch - A two-way latching, push-button switch in the DDM allows the vehicle operator to lock out the power window switches on each passenger door so that the passenger door power windows may be operated only from the master switches in the DDM.
- Power Window Switches - The DDM houses a two-way momentary power window switch for the driver side front door. This switch also has a second detent in the Down direction and internal circuitry to provide an Auto-Down feature for the driver side front door power window. In addition to the power window switch for its own door, the DDM houses individual master switches for each passenger door power window.
The DDM also incorporates several green Light- Emitting Diodes (LED s) that illuminate the power lock and power window switch paddles, and the power mirror switch directional buttons to improve switch visibility in dark ambient lighting conditions. The DDM cannot be adjusted or repaired and, if faulty or damaged, the entire DDM unit must be replaced.
The Driver Door Module (DDM) combines a power lock switch, a driver power window switch with an Auto-down feature, master switches for each passenger door power window, a power window lockout switch, a power mirror selector switch, and four power mirror adjustment switches in a single unit. The switches in the DDM can be diagnosed using conventional diagnostic tools and methods.
Power Lock Switch
The DDM power lock switch circuitry is connected in series between ground and the driver door switch mux input of the instrument cluster. Each power lock switch position (Lock, Unlock, and Neutral) provides a different resistance value to the instrument cluster input, which allows the instrument cluster to sense the switch position. Based upon the power lock switch input, the instrument cluster controls the battery and ground feed outputs to the individual power lock motors to lock or unlock the door latches. The Light-Emitting Diode (LED) in the DDM power lock switch is connected to battery current through the power window circuit breaker in the Integrated Power Module (IPM) on a fused ignition switch output (run-acc) circuit so that the switch will be illuminated whenever the ignition switch is in the ON or Accessory positions.
Power Window Switches
The DDM power window switch circuitry is connected to battery current through a circuit breaker in the Integrated Power Module (IPM) on a fused ignition switch output (run-acc) circuit so that the power windows will operate whenever the ignition switch is in the ON or Accessory positions. Each two-way, momentary master passenger power window switch in the DDM provides battery current and ground to the individual power window switches on each passenger door so that the power window switch controls the battery current and ground feeds to its respective power window motor. The DDM switch for the driver side front door power window is labeled "Auto" and includes an auto-down feature. When this switch is depressed to a second momentary detent position and released, the driver door power window is automatically operated through an internal circuit and relay to its fully lowered position. The Auto-down event is cancelled if the switch paddle is depressed a second time in either the Up or Down direction. When the two position window lockout switch in the DDM is depressed and latched in the lockout position, the battery current feed to each of the individual passenger power window switches is interrupted so that the passenger door power windows can only be operated from the master switches in the DDM. The window lockout switch also controls the battery current feed for the LED in each passenger power window switch so that the switch will not be illuminated when it is locked out.
Power Mirror Switches
The DDM power mirror switch circuitry is connected to battery current through a fuse in the IPM on a fused B(+) circuit so that the power mirrors remain operational regardless of the ignition switch position. A rocker type selector switch has three positions, one to select the right mirror, one to select the left mirror, and a neutral Off position. After the right or left mirror is selected, one of four directional buttons is depressed to move the selected mirror Up, Down, Right or Left. The DDM power mirror switch circuitry controls the battery current and ground feeds to each of the four (two in each mirror head) power mirror motors. The Light-Emitting Diode (LED) in the DDM power mirror switch is connected to battery current through the power window circuit breaker in the IPM on a fused ignition switch output (run-acc) circuit so that the switch directional buttons will be illuminated whenever the ignition switch is in the ON or Accessory positions.
REMOTE KEYLESS ENTRY MODULE
When an RKE lock message is sent to the instrument cluster, the instrument cluster actuates the door locks, the interior lighting is turned OFF, the horn chirps (if this feature is enabled), the park 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 sent to the instrument cluster, the instrument cluster actuates the driver side front door (or all doors if this feature is enabled) unlock, the interior lighting is turned ON and, if the vehicle is so equipped, the VTSS is disarmed.
When an RKE panic message is sent to the instrument cluster, the instrument cluster actuates the driver side front door (or all doors 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 sent to the instrument cluster. A vehicle speed of about 25.7 kilometers-per-hour (15 miles-per-hour) will also cancel the panic event.
Refer to the owner's manual for more information on the features, use and operation of the RKE system.
Whenever the vehicle battery power is interrupted, the Remote Keyless Module (RKE) Module will retain all vehicle access codes in its memory. When replacing or adding a key fob transmitter (maximum of 4) a DRB III scan tool is required to program the RKE Module to accept the new Vehicle Access Code if a customer owned transmitter is not available.
If a functioning transmitter is available, (Refer to POWER LOCKS/KEYLESS ENTRY TRANSMITTER - STANDARD PROCEDURE).