Power Locks - Operation

OPERATION

POWER LOCK SYSTEM

The power lock system uses non-switched battery current received through a fused B(+) fuse in the Body Control Module (BCM) (also known as the Common Body Controller/CBC) so that the system remains operational regardless of the ignition switch position. The BCM is the primary power lock system controller. The power lock switches are hard wired to their respective Driver Door Module (DDM) or Passenger Door Module (PDM). The BCM, the DDM and the PDM all communicate with each other and with other electronic modules in the vehicle over the Controller Area Network (CAN) data bus.

When a door module receives an input from a power lock switch, it sends the appropriate electronic Lock Request or Unlock Request message to the BCM over the CAN data bus. The BCM responds to these request messages by providing the appropriate outputs to each of the power lock motors that lock or unlock the doors, ram box latches and the tailgate. The BCM also stores the power lock system Customer Programmable feature settings received over the CAN data bus from the Electronic Vehicle Information Center (EVIC). The BCM 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 microprocessor and software contained within the BCM, the DDM and the PDM. When one of these modules 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.

REMOTE KEYLESS ENTRY SYSTEM

The Remote Keyless Entry (RKE) system uses non-switched battery current received through a fused B(+) fuse in the Body Control Module (BCM) (also known as the Common Body Controller/CBC) so that the system remains operational regardless of the ignition switch position. The Radio Frequency Hub (also known as the RF Hub) is the primary RKE system controller as well as the Radio Frequency (RF) RKE receiver. The RF Hub validates the vehicle access code of each RKE transmitter (also known as FOB with Integrated Key/FOBIK) from which it receives RF signal inputs. It ignores requests from any transmitter for which it has no stored vehicle access code.

The RF Hub communicates and shares resources with the BCM and many other electronic modules in the vehicle over the CAN data bus. The RF Hub also stores the RKE system Customer Programmable feature settings received over the CAN data bus from the Electronic Vehicle Information Center (EVIC). When the RF Hub receives an input from a valid transmitter source, it uses these settings and internal programming to send the appropriate electronic request messages to the BCM 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 microprocessor and software contained within the RF Hub. When the RF Hub monitors a problem in any of the RKE system circuits or transmitters, it stores a Diagnostic Trouble Code (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.

ROLLING CODE

The rolling code feature changes part of the transmitter message each time that it is used. The transmitter message and the receiver message increment together. Under certain conditions with a rolling code system, such as pressing a button on the FOBIK transmitter over 255 times outside of receiver range or replacing the battery, the receiver and transmitter can fall out of synchronization. To re-synchronize, press and release the UNLOCK button on the FOBIK transmitter repeatedly (it may take up to eight cycles) while listening carefully for the power door locks in the vehicle to cycle, indicating that resynchronization has occurred.

The lock function works from the FOBIK transmitter even in an out of synchronization condition, therefore it could be verified by pressing the LOCK button on the FOBIK.