Function description - ra80001400010x(0010)
A. General, B. Operation, C. Function, D. Components, E. Immobilizer stage Central Locking System Model 140
A. General
1st version up to 11/94, up to 08/95
The central locking can be locked or unlocked centrally from the driver's and front passenger's door and from the trunk lid by operating the key. The central locking can also be locked or unlocked via the central locking (CL) interior control switch (S85) if the vehicle was previously unlocked from outside. When a front door is opened, the vehicle unlocks centrally if it was previously locked via the central locking interior control switch. All the doors, the trunk lid and the tank flap are incorporated in the central locking.
2nd version as of 12/94, except
The central locking (CL), anti-theft alarm system (ATA) and convenience feature (CF) can no longer be actuated with the mechanical key on vehicles with infrared remote central locking as of 12/93 (except
).
For the function of the stage 1 immobilizer the pneumatic system equipment (A37, A37/1) has an electrical output (pin 1 on plug 2) to actuate the immobilizer relay (K38).
The central locking can be locked or unlocked centrally from the outside only by using the infrared transmitter key. The central locking can be locked or unlocked from inside the car using the CL interior control switch (S85) provided the car was unlocked beforehand using the IRCL. If a front door is opened, the car is unlocked centrally provided it was locked beforehand using the CL interior control switch. All the doors, the trunk lid and the fuel filler flap are integrated in the central locking.
3rd version as of 09/95
The central locking can be locked or unlocked centrally from the outside only by using infrared transmitter key or by operating the mechanical key. The central locking can be locked or unlocked from inside the car using the CL interior control switch (S85) provided the car was unlocked previously from the outside. If a front door is opened, the car is unlocked centrally provided it was locked beforehand using the CL interior control switch. All the doors, the trunk lid and fuel filler flap are integrated in the central locking.
B. Operation
1st version up to 11/94,
Driver's door
The central locking can always be operated when the driver's door is closed . Turn key clockwise as far as the stop to lock, turn key anticlockwise as far as the stop to unlock. When the handle in the door trim is pulled, the car unlocks centrally provided it was previously locked using the central locking interior control switch.
Front passenger door
The central locking can be operated from the closed or opened front passenger door using the key or handle in the door trim (as in the case of the driver's door).
Trunk lid
The central locking can be operated using the key when the trunk lid is open or closed.
Unlocking:
Turn key anticlockwise as far as the stop and withdraw vertically.
Locking:
Turn key clockwise as far as the stop and withdraw vertically.
Additional security:
Turn key clockwise as far as the stop and withdraw in the horizontal position. The trunk lid now remains locked even if the doors are unlocked centrally.
Emergency unlocking of fuel filler flap
If the central locking fails, the fuel filler flap can be unlocked manually using a red emergency release knob on the fuel filler flap actuator.
2nd version as of 12/94, except
The central locking, the ATA and the convenience feature can be operated from the outside only using the infrared remote control for the central locking.
Emergency unlocking of fuel filler flap
If the central locking fails, the fuel filler flap can be unlocked manually using a red emergency release knob on the fuel filler flap actuator.
C. Function
1st version up to 11/94,
Sequence of functions for unlocking car at driver's door
The electrical switch (SN1) in the lock is operated when the key in the lock cylinder is turned in the "open" direction. This switch then conducts a negative voltage along its control line to the pneumatic system equipment.
The pneumatic system equipment (A37, A37/1) operates and generates a pressure which flows along a system of lines to all the pneumatic actuators. The diaphragms in the actuators are pressed up, operate the locks via linkages and unlock them. The fuel filler flap actuator unlocks the flap directly.
A pressure switch switches off the supply pump if a pressure of about 450 mbar is reached in the system.
The pneumatic line system and the actuators are now depressurized again by the pneumatic system equipment (A37, A37/1) - the system is depressurized and the unlocking process is complete.
The locking process proceeds in a similar way to the unlocking process. However, when the key is turned clockwise, a second electrical switch (SN2) in the lock is operated. This switch also conducts ground along its control line to the pneumatic system equipment (A37, A37/1). The direction of rotation of the pump motor is reversed and it thus generates the vacuum required for locking.
2nd version as of 12/94, as of 09/95
Sequence of functions for unlocking the car using the infrared remote central locking (IRCL)
Aim the remote control with the transmitter output at the receiver in the interior mirror and press the transmission key. The infrared control module then supplies a negative voltage along its control line to the pneumatic system equipment.
The pneumatic system equipment (A37, A37/1) operates and generates a pressure which flows along a system of lines to all the pneumatic actuators. The diaphragms in the actuators are pressed up, operate the locks via linkages and unlock them. The fuel filler flap actuator unlocks the flap directly.
A pressure switch switches off the supply pump if a pressure of about 450 mbar is reached in the system.
The pneumatic line system and the actuators are now depressurized again by the pneumatic system equipment (A37, A37/1) - the system is depressurized and the unlocking process is complete.
The locking process proceeds in a similar way to the unlocking process. However, the next time the transmission key is pressed, ground is likewise conducted to the pneumatic system equipment (A37, A37/1) along the second control line of the infrared remote control module. The direction of rotation of the pump motor is reversed and it thus generates the vacuum required for locking.
Function diagram
1st version up to 11/94,
Function diagram
2nd version as of 12/94, as of 09/95
D. 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 (
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.
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).
| Pressure cut-off point of central locking | (mbar) | approx. 550 - 620 |
| Switching time of central locking | (s) | approx. 1 |
| Safety switching time if central locking leaks | (s) | 10 ± 1 |
| Safety switching time if auxiliary appliances leak | (s) | approx. 60 |
| Power consumption | (A) | max. 10 |
| Closed-circuit current draw terminal 30 | (mA) | < 2 |
| Closed-circuit current draw terminal 15 (auxiliary appliances) | (mA) | < 50 |
Door actuators
All actuators have a pneumatic connection (a) for a quick-fit connector.
Only with infrared remote control up to approx. 11/93 and/or anti-theft alarm system, does the driver's door central locking actuator have an electrical connection (arrow).
Trunk lid actuator
The trunk lid pneumatic actuator (6) is connected to the trunk lid lock via a locking linkage.
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).
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.
- Left front door
- Right front door
- Left rear door
- Right rear door
- Filler neck flap
- Trunk lid
E. Immobilizer stage 1 as of 12/93 up to 11/94
As of 12/93 up to 11/94 the pneumatic system equipment (A37, A37/1) will have an electrical output (pin 1 on plug 2) to actuate the immobilizer relay (K38) for the function of the immobilizer.
If the vehicle is unlocked from outside via one of the three operating points (convenience switch SN1 operates), the immobilizer output is switched to ground. After the ignition is switched on, the immobilizer relay (K38) picks up and closes the starter current circuit. The vehicle can be started.
If the vehicle is locked from outside via one of the three operating points (convenience switch SN2 operates), ground actuation for the immobilizer relay (K38) is open-circuited via the immobilizer output.
The starter current circuit is open-circuited as a result and the vehicle cannot be started.
Location of components for immobilizer stage 1
(shown on sedan)