Components
The vacuum supply pump may also be known as the PSE Control Module (A37). Please refer to "Pneumatic System" for more information. Pneumatic System
1. Supply pump (M14/1, M14/2)
There are 7 versions of supply pumps:
a) Supply pump for the central locking and vacuum M14/1 (production up to 09/91).
Supply pump with 2 pneumatic connections.
Identification ZV: vacuum and pressure for central locking
Identification PU: vacuum for auxiliary consumers for supporting the intake manifold vacuum
b) Supply pump for the central locking with orthopaedic seat backrest, vacuum and interior central locking (special equipment up to 12/93).
Supply pump with 4 pneumatic connections.
Identification ZV: vacuum and pressure for central locking
Identification PU: vacuum for auxiliary consumers for supporting the intake manifold vacuum
Identification IZV: vacuum and pressure for interior central locking
Identification PU (#): pressure for the orthopaedic driver's seat backrest
c) Supply pump for central locking with vacuum and interior central locking (production as of 10/91 up to 12/93).
Supply pump with 3 pneumatic connections.
Identification ZV: vacuum and pressure for central locking
Identification IZV: vacuum and pressure for interior central locking
Identification PU (#): pressure for the orthopaedic driver's seat backrest
d) Supply pump for the central locking with vacuum and interior central locking and electrical actuation of starter lock-out relay (K38) (production as of 01/94 to 11/94).
Supply pump with 3 pneumatic connections.
Identification ZV: vacuum and pressure tar central locking
Identification IZV: vacuum and pressure for interior central locking
Identification PU (#): pressure for the orthopaedic driver's seat backrest
e) Supply pump for the central locking with orthopaedic seat backrest, vacuum and interior central locking and electrical actuation of starter lock-out relay (K38) (special equipment as of 01/94 to 11/94).
Supply pump with 4 pneumatic connections and electrical actuation of starter lock-out relay (K38).
Identification ZV: vacuum and pressure for central locking
Identification PU: vacuum for auxiliary consumers for supporting the intake manifold vacuum
Identification IZV: vacuum and pressure for interior central locking
Identification PU (#): pressure for the orthopaedic driver's seat backrest
f) Supply pump for central locking with vacuum and interior central locking as well as electrical input for CL interior control switch (standard as of 09/95).
Supply pump with 3 pneumatic connections and electrical input for CL interior control switch.
Identification ZV: Vacuum and pressure for central locking
Identification PU: Vacuum for auxiliary loads for manifold vacuum assist.
Identification IZV: Vacuum and pressure for interior central locking.
g) Supply pump for central locking with orthopedic backrest, vacuum and interior central locking as well as electrical input for CL interior control switch (special equipment as of 09/95).
Supply pump with 4 pneumatic connections and electrical input for CL interior control switch.
Identification ZV: Vacuum and pressure for central locking
Identification PU: Vacuum for auxiliary loads for manifold vacuum assist.
Identification IZV: Vacuum and pressure for interior central locking.
Identification PU (#): Pressure for orthopedic driver's backrest.
NOTE: Since the pin assignment in the electrical connector has been changed, supply pumps with/without output for control of the starter lockout relay (production breakpoint 01/94) and supply pumps with input for CL interior control switch (production breakpoint 09/95) are not interchangeable.
The control unit for the central locking
The supply pump is supplied with a negative control voltage for locking and a positive control voltage for unlocking from the actuators. The supply pump produces pressure for unlocking and vacuum for locking (about 600 mbar).
The change of the pressure direction is controlled by the clockwise or anti-clockwise running of the motor and the pump. It is thus ensured, that the command which was last issued is carried out.
In the event of serious leaks, the supply pump switches off after 25 - 30 seconds (safety switching time). The electronic control has several logic functions, which avoid faulty switching and disturbances. In addition the control unit has a leakage current detection, whereby the leakage current cannot result in automatic functions, since the control inputs concerned are switched off.
a) Distributor plug for the interior central locking and orthopaedic backrest (special equipment)
b) Distributor plug for the central locking and vacuum (production)
c) Electrical cable harness
Pneumatic connection
Distributor plug (a, b) with identification of the individual connections.
NOTE: Distributor plugs (a, b) are eliminated as of installation of pneumatic line sets produced using the stamping method (04/95).
Electrical connection
12-pin connector with insertion and removal aid. Connection and disconnection is effected with the help of a gripping device.
Assignment of the electrical connections of the M14/1 or M14/2 supply pump
List of the supply priorities
1. Emergency opening
2. Infrared remote operation
3. Central locking
4. Interior central locking
5. Vacuum for auxiliary consumers
After switching on the ignition, the vacuum supply can only begin after a delay period of 5 - 8 seconds.
6. Pressure for orthopaedic driver's seat backrest.
After switching on the ignition the pressure supply can only begin after a delay period of about 2 seconds.
Control unit for auxiliary consumers, vacuum
The M14/1 or M14/2 supply pump supports the units depending on intake manifold vacuum, e.g. automatic heating or air conditioning.
If the vacuum in the storage reservoir reaches a value of about 410 - 390 mbar, the supply pump starts up for 2 seconds when the ignition is switched on. In the event of severe leaks in the vacuum system the pump switches off after a continuous running period of 60 - 70 seconds. If the supply pump constantly switches on and off in time intervals shorter than 17 ± 2 seconds due to slight leaks, these switching operations are summated by a leakage detection system and the pump switches off after 31 switching operations. This process is interrupted by switching off the ignition and starts all over again. The summated switching operations are erased, as soon as the supply pump has not been switched on for longer than 17 ± 2 seconds.
PU Identification
Connection for auxiliary consumers, vacuum.
From the distributor plug on the supply pump, connection PU a vacuum line leads straight to the vacuum distributor block in the engine compartment.
Control of emergency opening
Emergency opening may only be carried out if the steering lock interrogation switch is open (key in place) and continuous earth (-) is applied to the emergency opening control input for atleast 0.1 seconds.
Thereafter the supply pump starts running in the direction "unlocking" after a delay of about 5 seconds.
Interior central locking control unit
The interior central locking is unlocked, when:
- The control unit of the interior central locking is earthed and remains in this condition independent of the central locking.
- The control input for the driver's door or passenger door is earthed and simultaneously the control unit for comfort/ATA is earthed for a short time.
- The control input of the trunk lid is earthed.
- The control input of the infrared remote control is earthed.
The interior central locking is unlocked, when:
- Positive voltage is supplied to the control input of the interior central locking.
- A positive voltage is applied to the control input of the driver's door or passenger door and when simultaneously the control unit of the comfort/ATA is earthed briefly.
- Positive voltage is applied to the control input of the trunk lid.
- Positive voltage is applied to the control input of the infrared remote control.
The interior central locking is connected to the central locking by a 3/2 directional control valve on the supply pump.
Actuation of the control input of the interior central locking will only ever operate the interior central locking.
If the interior central locking is operated indirectly by the central locking, then the central locking is always operated first.
In the event of severe leakage in the system the pump switches off after a continuous running time of 20 - 30 seconds.
Control unit for Infrared remote control
If the supply pump receives a positive signal via the control input of the infrared remote operation, it carries out an unlocking process. Likewise, the interior central locking unlocks, if necessary, provided that the control input of the interior central locking is earthed.
When there is a negative signal to the control input of the infrared remote control the central locking locks, and if need be, the interior central locking.
Control unit for the orthopaedic driver's seat backrest
The M14/2 supply pump produces the necessary pressure for the orthopaedic driver's seat backrest.
It applies pressure to the storage reservoir up to a maximum of 590 mbar.
If this pressure reduces to about 200 - 230 mbar the supply pump starts up again until the maximum pressure of 590 mbar has been reached again.
In the event of severe leakage in the pressure system (orthopaedic driver's seat backrest) the pump switches off after a continuous running period of 60 - 70 seconds.
If the supply pump constantly switches on and off in time intervals shorter than 17 ± 2 seconds due to slight leaks, these switching operations are added up by a leakage detection system and the pump switches off after 31 switching operations. This process is interrupted by switching off the ignition, and starts all over again. The added-up switching operations are erased, as soon as the supply pump has not been switched on for longer than 17 ± 2 seconds.
PU (#) Identification (special equipment)
Connection for orthopaedic driver's seat backrest.
2. Pneumatic line system and connections
Pneumatic lines with quick-fit connection
All pneumatic lines have a plug on their ends which lock into the pneumatic connecting bush of the elements.
a Distributor plug - interior central locking and orthopaedic backrest (special equipment)
b Distributor plug - central locking and vacuum (standard)
The pneumatic lines lead straight to the elements from distributor plugs on the supply pump
The ends of the pneumatic lines are identified. The identification indicates to which pneumatic element the line belongs.
Identification Element
VL Left door actuator
VR Right door actuator
HD Trunk lid lock actuator
KE Tank flap element
NOTE: As of 09/95 pneumatic line sets are used, which are produced using a new production method, the so-called stamping method. The pneumatic distributors used previously on the pneumatic control module have been eliminated. A pneumatic line plugged onto the pneumatic control module leads to a 6-way distributor for distribution of the dual pressure for central locking.
From this 6-way distributor a separate pneumatic line leads to each of the central locking elements. Letters on the 6-way distributor indicate the central locking element to which the pneumatic line leads. Connections C and D are plugged.
A. Left door
B. Trunk lid
C. Plugged
D. Plugged
E. Right door
F. Tank flap
Distributor plug - upper side
Distributor plug - under side
3. Pneumatic distributor plug
The connecting bushes on the distributor plug are identified.
The identification indicates to which pneumatic system the connected lines lead.
NOTE: The pneumatic distributor plugs have been eliminated as of the production breakpoint for the stamping production method (09/95).
Identification Pneumatic system
ZV Central locking
PU Vacuum - auxiliary consumers
IZV Interior central locking
PU (#) Orthopaedic driver's seat backrest
4. Ignition starter switch
Switch-steering lock Interrogation S2/1s2
This switch earths and thus activates the supply pump when the key is removed or is inserted again after removal, but has not been operated (key position "0" on the steering lock).
5. Switchover valve for venting central locking of the driver's door Y65/1 (passenger door Y65/2) (vehicles up to 12/93)
These valves are accommodated beneath the left and right driver's/passenger's seat. They vent the pneumatic line to the driver's and passenger door after locking or unlocking
NOTE: Since the pin assignment in the electrical connector has been changed, supply pumps with/without output for control of the starter lockout relay (production breakpoint 01/94) and supply pumps with input for CL interior control switch (production breakpoint 09/95) are not interchangeable.