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 serial data bus for bi-directional communication with the Wireless Ignition Node (WIN). The WIN then stores a Diagnostic Trouble Code (DTC) and sends an electronic error message to the Cab Compartment Node (CCN), over the Controller Area Network (CAN) data bus, and a SERVICE COLUMN LOCK message will appear in the instrument cluster 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 FOBIK present in the vehicle or 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 vehicle or 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 key remains in the ignition switch.

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 B(+) circuit, and receives battery voltage to operate the locking bolt in the locked direction only when the key 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 serial data bus upon initialization. This code is stored in the memory of the module and cannot be changed. Therefore, if the WIN requires service replacement, a new shaft lock module will also be required. 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 shaft lock module cannot be adjusted or repaired and, if ineffective or damaged the shaft lock module must be replaced. Whenever a shaft lock module is replaced the WIN must also be replaced. To remove a locked shaft lock module from a removed steering column Shaft Lock Module - Removal