Door Lock Heating (TSH/ZKE)

Door Lock Heating (TSH/ZKE):

General Block Diagram:

Notes:

These instructions apply only when a ZKE general module is installed.

Functional Description:

The door lock heating system (TSH) is controlled by the general module (GM) of the central body electronics (ZKE). The door lock heating relay is located in the relay module (RM). The working circuit is protected by the external fuse relay. Also refer to Central Body Electronics (ZKE).

Operating Principle:

The door lock heating is activated by the door handle contact of the driver's door. Mounted on the door lock of the driver's door is a heating ring which heats up and prevents the lock from icing up. Certain switch-on conditions must be met to activate the door lock heating system.

Switch-On Conditions:

1. Vehicle locked with central locking system.
2. At least 35 seconds must have elapsed after locking.
3. Driver's door handle lifted.

After lifting the handle for 5 seconds, the door lock heating system switches on for approx. 40 seconds. After this period, it can be switched on again by lifting the handle. However, the door lock heating system can be activated only 3 times within a period of 10 minutes. An inhibit function is then active for 16 minutes but it can be reset prematurely by unlocking and locking the vehicle.

Switch-Off Conditions:

1. Automatically after 40 seconds.
2. Vehicle is unlocked.
3. Ignition lock in position R or 15.