Power Lock System Explanation

POWER LOCK SYSTEM OPERATION
The power lock system uses non-switched battery current received through a fused B(+) fuse in the Totally Integrated Power Module (TIPM) so that the system remains operational regardless of the ignition switch position. The TIPM is the primary power lock system controller. The power lock switches are hard wired to the TIPM. When the TIPM receives an input from a power lock switch, it responds by providing the appropriate outputs to each of the power lock motors to lock or unlock each of the door and swing gate latches.

The TIPM also stores the power lock system Customer Programmable feature settings received over the CAN data bus from the Electronic Vehicle Information Center (EVIC) circuitry of the Electro Mechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN). The TIPM uses these settings and internal programming along with hard wired and electronic message inputs to determine the proper outputs needed to produce each of the appropriate power lock system features.

The power lock system circuits are continually monitored and controlled by the microcontroller and software contained within the TIPM. When the TIPM monitors a problem in any of the power lock system circuits or components, it stores a fault code or Diagnostic Trouble Code (DTC) in its memory circuit.
The hard wired circuits between components related to the power lock system may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

However, conventional diagnostic methods will not prove conclusive in the diagnosis of the power lock system or the electronic controls or communication between other modules and devices that provide features of the power lock system. The most reliable, efficient, and accurate means to diagnose the power lock system or the electronic controls and communication related to power lock system operation, as well as the retrieval or erasure of a DTC requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.


POWER LOCK SYSTEM DESCRIPTION
A power operated door and swing gate lock system is standard factory-installed equipment on this vehicle. The power lock system allows all of the doors and the swing gate to be locked or unlocked electrically. Locking or unlocking the vehicle using the power lock system can be accomplished by two different methods:

Power Lock System - Operating a power lock system switch on either front door inside trim panel will lock or unlock the latches of the doors and the swing gate.

Remote Keyless Entry System - Depressing the Lock or Unlock button of the Remote Keyless Entry (RKE) system transmitter can also be used to lock or unlock the latches of the doors and the swing gate. The specific locks operated and the number of FOBIK button presses required varies depending upon the Customer Programmable settings chosen by the vehicle operator.


The power lock system includes the following major components, which are described in further detail elsewhere in this service information:
Electronic Vehicle Information Center - The Electronic Vehicle Information Center (EVIC) is a digital display integral to the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN), which is located on the instrument panel in front of the driver. Refer to CENTER, ELECTRONIC VEHICLE INFORMATION, DESCRIPTION .
Power Lock Motors - A reversible electric power lock motor is integral to the latch of each front and rear door and the swing gate.
Power Lock Switches - A power lock switch is located just forward of the arm rest of each front door inside trim panel.
Totally Integrated Power Module - The Totally Integrated Power Module (TIPM) is located in the engine compartment. Refer to MODULE, TOTALLY INTEGRATED POWER (TIPM), DESCRIPTION
.

These components and their controls are combined to provide the following power lock system central locking and unlocking features:

Automatic Door Locking - Automatic door locking (also known as rolling door locks) automatically locks any unlocked door when the vehicle speed exceeds about 25.7 kilometers per hour (15 miles per hour). This is a Customer Programmable feature.

Automatic Door Unlocking - Automatic door unlocking (also known as automatic unlock doors on exit) automatically unlocks the doors after they were automatically locked when the vehicle speed exceeded about 25.7 kilometers per hour (15 miles per hour), the vehicle speed has returned to zero, the transmission shift lever is in the Neutral or Park positions and the driver side front door is opened. This is a Customer Programmable feature.

Customer Programmable Features - The vehicle operator interfaces with the TIPM, which is the power lock system controller, using the EVIC. An EVIC switch pod located on the left horizontal spoke of the steering wheel allows the vehicle operator to set or change the power lock system Customer Programmable Features through the EVIC display.

Door Lock Inhibit - Prevents locking the doors using a power door lock switch or the Lock button of the Remote Keyless Entry (RKE) system transmitter if the key is in the ignition and the driver side front door is open.

Enhanced Accident Response System - In the event of a vehicle impact that causes airbag deployment but leaves vehicle electrical power intact, the Enhanced Accident Response System (EARS) automatically turns OFF the supply of fuel to the engine, turns ON the interior courtesy lamps, turns ON the hazard warning flashers and unlocks the doors after the vehicle speed has returned to zero. This helps emergency responders in their efforts to render the appropriate assistance. The courtesy lamps and hazard flashers remain ON as long as the battery has power or until the key is removed from the ignition.

Illuminated Entry - Automatic illumination of the interior courtesy lamps when the vehicle is unlocked using the power lock system.

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. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices and grounds.

REMOTE KEYLESS ENTRY SYSTEM OPERATION
The Remote Keyless Entry (RKE) system uses non-switched battery current received through a fused B(+) fuse in the Totally Integrated Power Module (TIPM) so that the system remains operational regardless of the ignition switch position. The Sentry Key REmote Entry Module (SKREEM) (also known as the Wireless Control Module/WCM or the Sentry Key Immobilizer Module/SKIM) is the primary RKE system controller as well as the Radio Frequency (RF) RKE receiver. The SKREEM validates the vehicle access code of each RKE transmitter from which it receives RF signal inputs. It ignores requests from any transmitter for which it has no stored vehicle access code.
The SKREEM communicates and shares resources with the TIPM and many other electronic modules in the vehicle over the CAN data bus. The SKREEM also stores the RKE system Customer Programmable feature settings received over the CAN data bus from the EVIC circuitry of the CCN. When the SKREEM receives an input from a valid transmitter source, it uses these settings and internal programming to
send the appropriate electronic request messages to the TIPM and other electronic modules over the CAN data bus to invoke the proper RKE system features and responses.
The RKE system circuits and transmitter inputs are continually monitored by the microcontroller and software contained within the SKREEM. When the SKREEM monitors a problem in any of the RKE system circuits or transmitters, it stores a DTC in its memory circuit. The hard wired circuits between components related to the RKE system may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector
pin-out information and location views for the various wire harness connectors, splices and grounds.

However, conventional diagnostic methods will not prove conclusive in the diagnosis of the RKE system or the electronic controls or communication between other modules and devices that provide features of the RKE system. The most reliable, efficient, and accurate means to diagnose the RKE system or the electronic controls and communication related to RKE system operation, as well as the retrieval or erasure of a DTC requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

DOUBLE ACTIVATION UNLOCK PROCEDURE
1. Open the driver door, sit in the driver seat, and close the driver door.
2. Turn the ignition switch to the RUN position (without starting the vehicle) and then back to OFF. Repeat this step three additional times (for a total of four key ON/OFF cycles).
3. Within 10 seconds of switching the ignition switch to the OFF position for the last time (at the end of the fourth cycle in the above step), press the driver interior door lock switch to UNLOCK.
4. A single chime will be heard to verify that the customer programmable toggle of the double activation unlock was successfully completed.

NOTE: When toggling the double activation unlock feature (customer programmable), the toggle that happens will be from the last state of the double activation unlock. If the double activation unlock feature was enabled, after the toggle process, it will now be disabled and vice versa. There is no telltale to inform you of which state the double activation unlock feature is in.

AUTOMATIC DOOR LOCK AND UNLOCK (ROLLING LOCKS) PROCEDURE
1. Open the driver door, sit in the driver seat and close the driver door.
2. Turn the ignition switch to the ON position (without starting the vehicle) and then back to the
OFF position. Repeat this cycle three additional times for a total of four ignition switch cycles.
3. Within 10 seconds of switching the ignition switch to the OFF position at the end of the fourth cycle in the above step, press the driver interior door lock switch in the LOCK direction to lock the doors.
4. A single chime will be heard to verify that the customer programmable toggle of the automatic door locks was successfully completed.

NOTE: When toggling the automatic door lock (rolling lock) feature, the toggle that occurs will depend upon the last state of the automatic door lock feature. If the automatic door lock feature was enabled, it will now be disabled; and, if it was disabled, it will now be enabled. There is no telltale to inform you of the current state of the automatic door lock feature. The vehicle must be driven with the doors unlocked to a speed above 24 kilometers per hour (15 miles per hour) to confirm whether or not the automatic door lock feature is now enabled.
AUTOMATIC DOOR UNLOCK (UNLOCK ON EXIT) PROCEDURE
1. Open the driver door, sit in the driver seat and close the driver door.
2. Turn the ignition switch to the ON position (without starting the vehicle) and then back to the OFF position. Repeat this cycle three additional times for a total of four ignition switch cycles.
3. Within 10 seconds of switching the ignition switch to the OFF position at the end of the fourth cycle in the above step, press the driver interior door lock switch in the UNLOCK direction to unlock the doors.
4. A single chime will be heard to verify that the customer programmable toggle of the automatic door unlock was successfully completed.

NOTE: When toggling the automatic door unlock (unlock on exit) feature, the toggle that occurs will depend upon the last state of the automatic door unlock feature. If the automatic door unlock feature was enabled, it will now be disabled; and, if it was disabled, it will now be enabled. There is no telltale to inform you of the current state of the automatic door unlock feature. The vehicle must be driven with the doors unlocked to a speed above 24 kilometers per
hour (15 miles per hour) to lock the doors, then be brought to a full stop and the driver door opened to confirm whether or not the automatic door unlock feature is now enabled.