Seat Temperature Element: Description and Operation

Heated Seats

Note: This description applies up to and including 1990.

Functional Description:

The seat heating system is effective in the seat cushion and back rest of the driver's and passenger's seat. Rear seat heating is also available as an optional extra.

The heated seats consist of the following components:
- Back rest heating element
- Seat cushion heating element
- Seat heating switch

Additionally for rear heated seats:
- Seat heated relay

Additionally as of model year 1989:
- Seat heating relay, also for front heated seats

Operation Standby up to Model Year 1989:

The seat heating system is ready for operation as of ignition switch position "ignition ON". The green indicator lamp in the switch indicates that the seat heating is on.

Operation Standby as of Model Year 1989:

The seat heating system for the driver's seat is ready for operation only when the engine is running (detected by terminal 61).

In addition, the seat belt must be buckled (detected by microswitch in belt buckle).

The green indicator lamp in the switch signals that the seat heating is active.

Operating Principle:

- Switch setting 1 continuous heating - symbol 1 heating coil element - the heating elements of the seat cushion and back rest are connected in series = reduced heating capacity.
- Switch setting 2 heating-up - symbol 3 heating coil elements - the heating elements of the seat cushion and back rest are connected in parallel and therefore receive the full battery voltage = full heating capacity.

The seat heating switches are illuminated when the parking light is switched on. The switch light becomes brighter when seat heating is switched on.