Steering Column Lock Unit (708)

Steering Column Lock Unit (708)

Principal use
Locking the steering column to prevent attempted theft.

Type
The steering column lock (SCL) is an electronically controlled unit comprising the following components:







- Motorised locking pin.
- Motorised locking pin securement (only release, securement is by spring force).
- Hall sensor indicating locking pin is in locked position.
- Hall sensor indicating locking pin is in unlocked and secured position.
- Microprocessor

SCL is linked with the column integration module (CIM) and the ignition switch (ISM) and operates as follows:
- It locks the steering column in a two-stage procedure:
1. Releases the locking pin on command from CIM via a direct lead from ISM, which carries out an extra check for security reasons.
2. Inserts the locking pin into the steering column via a communication cable from CIM.
- It unlocks the steering column by extracting the locking pin on command from CIM via a communication cable.
- It indicates to CIM that the locking pin is in unlocked and secured position, partly via a communication cable direct to CIM and partly on a direct lead to ISM, which then forwards it to CIM via its own communication cable.

Connection
The steering column locking function is dependent on communication with ISM and CIM. CIM is the control module that governs the functions and ISM is used to prevent inadvertent SCL locking in case of a fault in CIM or SCL. CIM and SCL are married to each other. New units that are fitted must be married to each other and a unit that is removed for use on a new car must first be divorced from the old one.







SCL can only be removed from the steering column in unlocked position. An SCL malfunction that makes unlocking impossible means that the whole steering column must be changed.

Pin No. 1 - 6:

Wiring diagram, power supply