Electronic Steering Lock Module: Notes
DESCRIPTION
The Electronic Steering Lock (ESL) system consists of the following components:
| 1. | Refer to BODY CONTROL MODULE (BCM) . |
| 2. | Refer to RADIO FREQUENCY HUB (RFH) MODULE . |
| 3. | Refer to KEYLESS IGNITION NODE (KIN) . |
| 4. | Refer to ELECTRONIC STEERING LOCK (ESL) . |
Models manufactured for Europe-Middle East-Africa (EMEA) markets have an electromechanical device called an ESL that locks (key OFF) and unlocks (key ON) the steering upon request by the BCM. The ESL module is located on the top side of the steering column near the heated steering wheel control module.
The ESL module transmits data and communicates with the other modules involved in the Sentry Key Immobilizer System (SKIS) via CAN-FD and has a dedicated hardwired connection with the Brake System Control Module (BSCM) for vehicle speed data.
Under normal operating conditions, the ESL module unlocks the steering column if, and only if, the FOBIK in the vehicle is identified by the SKIS as a valid key.
OPERATION
The RFH module and the ESL module are not linked electronically. During servicing, one can be replaced independently of the other.
Steering Column Locking
Before sending the steering locking request to the ESL module, the BCM checks the following parameters:
- Ignition status: the transition from ON or ON with engine running to OFF must be detected.
- Driver side door status: the transition from driver side door closed to driver side door open must be detected.
- Automatic transmission status: the transmission must be in Park ("P").
If one of the three conditions is not satisfied, the BCM will not send the steering column locking request to the ESL module.
The ESL module receives the vehicle speed signal from the BSCM. The acquisition of the vehicle speed signal continues even after the ignition switch is turned OFF.
Steering Column Unlocking
When the BCM receives the information that the Start/Stop button has been pressed from the RFH module, it requests that the RFH module carry out key recognition. If the key is identified as a valid key, the BCM will send a steering column unlocking request to the ESL module. If instead the key is identified as an invalid key or missing key, the BCM will not send any steering column unlocking request.