Components

Pneumatic system equipment (A37, A37/1)
In addition to the familiar functions of central locking, the pneumatic system equipment assists the trunk lid remote control ((USA) only), the retractable trunk lid grip, backup assist, retractable rear head restraints, orthopedic seat backrest (lumbar support and multi-contour backrest) appliances as well as the appliances dependent on intake manifold vacuum, such as, for example, automatic heater or air conditioning.


NOTE: As of 01/94 up to 11/95 the pneumatic system equipment has an electrical output for the function of the immobilizer (pin 1 on plug 2) for the ground actuation of the immobilizer relay (K38).


(USA)
With the introduction of the trunk lid remote control model year 95 the pneumatic system equipment (A37, A37/1) has two additional electrical inputs (pin 9 trunk lid remote control switch S15, pin 10 vehicle speed signal), as well as one electrical output (pin 8 trunk lid remote control solenoid valve actuation Y65/3).






Technical data for pneumatic system equipment (A37, A37/1)







Tank flap actuator
Clip-type pneumatic actuator with direct locking linkage, anti-theft locking device and emergency release button.
A valve in the actuator prevents the locking mechanism from being able to be pushed back mechanically from the tank flap. The guide sleeve covers the locking linkage and prevents water reaching the linkage which may cause the actuator to freeze up in winter.

Pneumatic lines with quick-fit plug connection
The pneumatic lines have a plug at their ends which engages in the pneumatic connection bush of the actuators.

The pneumatic lines to the door actuators run to the actuators from the distributor plug on the pneumatic system equipment (A37, A37/1) via the door contact points.

The pneumatic lines to the tank flap actuator and trunk lid actuator run directly to the actuators from the distributor plug on the pneumatic system equipment (A37, A37/1).


NOTE: As of 8/94, pneumatic line sets will be used which are produced by means of a new manufacturing process, the so-called crimp-on technique. The pneumatic distributors which were previously mounted on the pneumatic system equipment will no longer be used. A pneumatic line mounted on the pneumatic system equipment leads to a 6-way distributor to distribute the bi-pressure of the central locking.

A separate pneumatic line runs to each of the central locking actuators from this 6-way distributor. Letters on the distributor indicate to which central locking actuator the pneumatic line leads.
A. Left front door
B. Right front door
C. Left rear door
D. Right rear door
E. Filler neck flap
F. Trunk lid