Shaft Lock Module - Operation

OPERATION

The electronic circuitry within the shaft lock module contains all of the logic circuits and components to monitor and control the operation of the shaft locking bolt. The module uses a dedicated Local Interface Network (LIN) data bus for bi-directional communication with the Wireless Ignition Node (WIN). If the module detects a problem with the positioning or operation of the locking bolt, it sends an error message to the WIN. The WIN then stores a Diagnostic Trouble Code (DTC) and sends an electronic error message to the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN) over the Controller Area Network (CAN) data bus, and a SERVICE COLUMN LOCK textual message will appear in the instrument cluster reconfigurable dot matrix display.

The shaft lock module continuously monitors inputs from the WIN and energizes the electric motor to move the locking bolt to the locked or unlocked position based upon that input. If the WIN indicates that the FOB with Integrated Key (FOBIK) present in the ignition switch is invalid, the locking bolt remains in the locked position. When the WIN indicates that a valid FOBIK is present in the ignition switch, the shaft lock module operates a motor to move the locking bolt to the unlocked position. However, to prevent inadvertent column locking due to a failure while the vehicle is being operated, the module cannot move the locking bolt from the unlocked position to the locked position as long as a FOBIK remains in the ignition lock cylinder.

The shaft lock module receives ground at all times through a hard wired remote ground point. The module receives battery voltage to operate and to move the locking bolt in the unlocked direction on a fused B(+) circuit through a fuse in the Junction Block (JB), and receives battery voltage to operate the locking bolt in the locked direction only when the FOBIK is removed from the ignition switch. These connections allow the module to remain operational, regardless of the ignition switch position.

For added system security, the shaft lock module learns a unique Secret Key code from the WIN over the LIN data bus upon initialization. This code is stored in the memory of the module and cannot be changed. Therefore, if either the WIN or the shaft lock module requires service replacement, both the WIN and the shaft lock module must be replaced. Another security code, called a PIN, is used to gain access to the WIN Secured Access Mode. The Secured Access Mode is required during service to initialize a new shaft lock module.

The hard wired inputs to the shaft lock module may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the shaft lock module or the electronic controls or communication between other modules and devices that provide some features of the Vehicle Theft Security System (VTSS). The most reliable, efficient, and accurate means to diagnose the shaft lock module or the electronic controls and communication related to shaft lock module operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.