Power Locks: Description and Operation
Central Locking System (ZV/ZKE):Notes:
This section is only applicable when a ZKE general module is Installed. Both central locking systems (ZV) are dealt with.
ZV with blocking of ZV drives
and
ZV with decoupling of ZV drives
Functional Description:
General Block Diagram:
The central locking system (ZV) is controlled by the general module (GM) of the central body electronics (ZKE). The relays for locking, unlocking and arresting are located in the relay module (RM). The system circuits are fuse-protected by means of an external fuse relay (refer to Central Body Electronics).
A differentiation is made between two locking systems:
1. Central Locking (ZV) with Blocking of ZV Drives:
The ZV drives are blocked internally in the arrest setting. In this case, it is not possible to pull out the locking buttons and thus unlock the door locks.
Installed in:
- 7 Series, E32: All models
- 5 Series, E34: All models up to and including model year 1991
2. Central Locking (ZV) with Decoupling of ZV Drives:
The ZV drives are decoupled internally in the arrest setting. Although it is possible to pull out the locking buttons, the door locks are still not unlocked (central locking system of 3 Series, E36)
Installed in:
- 5 Series, E34: All models as of model year 1992
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1. Central Locking (ZV) with Blocking of ZV Motor Drives:
1.1. Components:
Lock contacts:
Microswitches on door handles of the driver's door and passenger's door. Depending on the position of the door lock, they are activated via cams, they switch battery voltage (B+) to the general module and signal lock, unlock Or arrest.
Pin contacts:
Microswitches in the ZV motor drive (integral component). The pin contacts of the driver's door and passenger's door are activated by means of the lock
buttons, the contact of the rear lid via the rear lid lock.
The contacts switch battery voltage (B+) to the ZKE general module and signal lock Or unlock. From the passenger's door they signal only the unlock status. The pin contacts indicate the actual status of the doors (locked, unlocked). The rear doors are not equipped with pin contacts.
General module:
Processes the signals from the contacts and switches the relays in the relay module
Relay module:
Three relays are provided in the relay module for the central locking system.
ZV motor drives:
Electrical servo drive motors on the door locks. They are powered via the ZV relays in the relay module. The ZV drive is blocked internally in the arrest
status.
1.2. Central Locking (ZV) Functions:
The following functions are possible:
- Lock/arrest/unlock via door locks of driver's/passenger's door
- Unlock/lock via locking button of driver's door
- Unlock via locking button of passenger's door
- Lock/unlock via rear lid lock
- Workshop setting of rear lid (= vehicle unlocked, rear lid remains locked)
- Release via door locks of driver's/passenger's door
1.3. Door Lock of Driver's and Passenger's Door:
The lock contacts are operated by means of the door locks of the driver's and passenger's door. The following key positions are possible:
"1" Unlock/release:
The vehicle is unlocked and released, if applicable, the antitheft system is disarmed.
"2" Lock:
The vehicle is locked without being arrested. The lock buttons on the driver's and passenger's door can be pulled up from the inside and thus unlock the
vehicle.
The lock system is blocked mechanically to prevent locking when the driver's door is open. Locking can result in asynchronous setting of the door lock, see "5 Synchronization".
"3" Arrest:
The vehicle is arrested, the locking buttons are blocked and cannot be pulled out.
"4" Emergency unlocking, only passenger's door:
The passenger's door can be opened mechanically in the event of electrical faults. Raise door handle and turn door lock with vehicle key in "unlock" direction beyond the hard pressure point (position 4). To lock door, turn to right beyond hard pressure point (position 5).
After restoring normal electrical operation, the ZV drive must be Synchronized (synchronization between linkage and servo drive), see "5 Synchronization".
"5" Synchronization, driver's 8nd passenger's door
Turn door lock to right beyond hard pressure point (lock). Synchronization is necessary when:
- Vehicle was locked with driver's door open (driver's door asynchronous)
- Passenger's door was unlocked in emergency unlock mode (e.g. driver's door asynchronous)
1.4. Rear Lid Lock:
Function:
The pin contact in the ZV drive is operated by means of the rear lid lock. The vehicle can be locked and unlocked. If the vehicle is in arrest mode, the rear lid itself can be unlocked but the doors are not unlocked.
Workshop setting:
The key can be removed in the key position locked (9° to right). The rear lid can then be permanently locked even when the vehicle is unlocked electrically by means of the central locking system (workshop setting).
1.5. Locking Buttons:
The pin contacts in the ZV drives are operated by the locking buttons. The vehicle can be:
- Locked and unlocked via the locking button of the driver's door (driver's door closed!)
- Unlocked via the locking button of the passenger's door
Rear doors:
The locking buttons at the rear doors have no influence on the central locking system.
Important!
Driver's door:
The locking linkage of the central locking system is locked mechanically for as long as the driver's door is open.
Repeat lockout:
To avoid overloading, the central locking system is inhibited when the system is operated very often within a short period of time. The lockout feature is canceled after a defined waiting time.
Defect Information:
If a defect occurs In the central locking system (ZV), the driver is made aware of this by the central locking system reverting automatically to its initial status. The required function is performed only after operation for a second time.
Example: Vehicle is locked - driver's door defective, it is not locked - the central locking system (ZV) locks the doors, the doors are unlocked once again a short time later.
Crash sensor:
(Inertia switch) installation location: Under left rear seat. The crash sensor is effective only when the ignition switch is set to R or 15 (position 1 or 2). At the point of impact, the sensor briefly switches a ground signal to the general module. The vehicle is unlocked/released, the interior lights are switched on (only in switch position automatic interior lights), the hazard warning system is activated (only if crash and alarm sensor is installed) and the central locking system is disabled.
Canceling the lockout function: By turning the door lock in the unlock direction.
Switching off the hazard warning system: Switch on and off hazard warning system in vehicle.
2. ZV with Decoupling of ZV Motor Drives:
2.1. Components:
Lock contacts:
Microswitch on door lock of driver's and passenger's door. Depending on the position of the door lock, they are activated via cams, they switch battery
voltage (B+) to the general module and signal the arrest command.
The model "E34 touring" features lock contacts also on the tailgate.
Pin contacts:
Microswitch in ZV servo motor drive (integral component). The pin contacts of the driver's and passenger's door are activated by means of the locking buttons. The contact of the rear lid is operated via the rear lid lock.
The contacts switch battery voltage (B+) to the general module and signal lock Or unlock/release. The pin contacts indicate the actual status of the doors (locked, unlocked). The rear doors are note equipped with pin contacts.
General module:
Processes the signals from the contacts and switches the relays in the relay module
Relay module:
Three relays are provided in the relay module for the central locking system.
ZV motor drives:
Electrical servo drive motors on the door locks. They are powered by means of the ZV relays in the relay module.
2.2. ZV Functions:
The following functions are possible:
- Lock/arrest/unlock/release via door locks of driver's/passenger's door
- Lock/unlock via locking buttons of driver's and passenger's door
- Lock/unlock via rear lid lock
- Workshop setting of rear lid (- vehicle unlocked, rear lid remains locked)
5 Series, E34, touring model:
Lock contacts are operated by means of the lock on the tailgate. The vehicle can therefore be
- locked
- unlocked
- arrested
- released
via the tailgate lock.
2.3. Door Lock of Driver's and Passenger's Door:
The vehicle can be locked, arrested and unlocked/released via the door lock of the driver's and passenger's door.
The following functions can be performed:
"1" Unlock/release:
The vehicle is unlocked and released, if applicable, the antitheft system is disarmed.
"2" Lock:
The vehicle is locked without being arrested. The locking buttons on the driver's and passenger's door can be pulled up from the inside, thus unlocking the vehicle.
The lock system is inhibited electrically to prevent locking when the driver's door is open (immediately unlocked after locking).
Only the passenger's door can be locked with the passenger's door open, the other doors are not locked.
"3" Arrest:
The vehicle is set in arrest mode, the locking buttons are uncoupled in the turn-catch lock from the opening mechanism. The door is not unlocked when the
locking buttons are pulled up.
Emergency unlocking:
The driver's and passenger's door can be unlocked mechanically (position "1") in the event of electrical faults. An uncoupled locking button (after arresting) remains uncoupled also after emergency unlocking.
2.4. Rear Lid Lock:
The pin contact in the ZV motor drive is operated by the rear lid lock. The vehicle can be locked and unlocked. If the vehicle is in arrest mode, the rear lid itself can be unlocked but the doors are not unlocked.
The key can be removed in the key position locked (900 to right). The rear lid can then be permanently locked even when the vehicle is unlocked electrically by means of the central locking system (workshop setting).
2.5. Tailgate Lock on "E34 touring":
Lock contacts (microswitches) are operated by the tailgate lock of the "E34 touring". The vehicle can be locked, arrested and unlocked/released.
The vehicle can be locked and unlocked electrically by means of the locking buttons on the passenger's and driver's door. The locking buttons on the rear
doors have no influence on the central locking module.
2.6. Locking Buttons:
The vehicle can be locked and unlocked electrically by means of the locking buttons on the passenger's and driver's door. The locking buttons on the rear doors have no influence on the central locking module.
Vehicle in arrest mode:
The locking buttons are uncoupled mechanically from the ZV motor drives when the vehicle is centrally arrested. This means:
Although the locking button can be pulled up the door is not unlocked. This function is effective on All doors.
Door open:
Driver's door:
If the locking button is pressed down when the driver's door is open, the vehicle is locked electrically and then unlocked automatically. This feature avoids the vehicle being locked unintentionally.
Passenger's door:
Only the passenger's door is locked mechanically if the locking button is pressed down while the passenger's door is open. Electrical locking of the vehicle does not take place.
Rear doors:
The locking buttons on the rear doors have no influence on the central locking system.
2.7. ZV Motor Drive:
Pin Assignments:
Pin Explanation
1,2,3 Wires to relay module, electric motor activation
4,5 Wires to general module, signaling lock(unlock
6 Wire to fuse, B+ for pin contact
Switching logic:
Pin Unlock Lock Arrest
1 from module B+ from module B- from module B-
2 from module B- from module B- from module B+
3 from module B- from module B+ from module B+
4 B+ open open
5 open B+ B+
6 B+ from fuse B+ from fuse B+ from fuse
2.8. Arrest Vehicle:
General:
The "arrested" status is intended to prevent the vehicle being opened by way of impermissible manipulation.
Since it is not possible to unlock and therefore open the doors from the inside in arrested status, this function is linked to a series of conditions.
Conditions:
Arresting is only possible when:
- Ignition and terminal R are switched oft, i.e. ignition switch in position "0",
- The driver's door was opened at least once after switching off the ignition,
- The driver's door is closed.
2.9. Central Locking Functions:
Fig. 1: Unlocked status:
Fig. 1: Unlocked status:
The figure opposite shows the ZV motor drive "1" and the corresponding mechanics in the turn-catch lock in unlocked status.
The connecting piece "4" can be turned from the door lock Or by the locking button in conjunction with the connecting piece "5,' and "6". When the part "4" is turned it uncouples the door outer handle from the opening mechanism.
Fig. 2: Locked status:
Fig. 2: Locked status:
The figure opposite shows the ZV motor drive and the corresponding mechanics in the turn-catch lock when locked.
The part "4" has been turned. Consequently, the slide "3" has been moved. The pin contact "7" is switched. It switches B+ to the ZKE general module and
signals "lock".
Sequence of electrical central locking:
The electric motors "10" in the ZV motor drives "1" receive their power supply. The spindle nuts "2" in the ZV motor drives are moved by means of a spindle. They are connected to the slide blocks "3" and thus cause the connecting piece "4" to rotate. The motors switch off as soon as the limit switches "9" are reached.
As a result, the outer door handles on All doors are uncoupled from the opening mechanism. A locked door can be unlocked by way of the inner door handle. The handle must be pulled twice for this purpose.
The vehicle can be unlocked once again by pulling up the locking button. Part "4" is turned back by means of parts "5" and "6". The slide block "3" is moved away from the pin contact "7" This signals "unlock" and initiates the power supply to the ZV motors. The part "4" is turned back to the unlock position.
The vehicle can also be unlocked by means of the door lock. In this case, the part "4" is turned by the door lock.
Fig. 3: Arrested status:
Fig. 3: Arrested status:
Explanation:
In arrest mode, the locking button is mechanically uncoupled from the ZV motor drive.
When the vehicle is arrested, it can only be unlocked via the door locks of the driver's door Or passenger's door.
Although the locking buttons can still be pulled up in arrest mode, they do not unlock the doors.
The rear lid can be unlocked also in arrest status, however, no doors are unlocked in this case.
Procedure:
A microswitch is operated by the driver's door (also the tailgate lock in E34 touring) when it is turned to the "arrest" position.
The electric motors "10" receive their power supply. The spindle nut "2" is moved. It uncouples from the slide blocks "3" and moves the lever "8". This lever uncouples the locking button from the "unlocking mechanism" in the turn-catch lock.
Unlocking is now only possible via the door locks. They are connected to pan "4". Part "~ moves back the sliding block "3" when the door lock is turned to the "unlock" position. The slide block "3'. is moved away from the pin contact "7". This signals "unlock" and triggers the power supply to the ZV motors. The spindle nuts "2" in All ZV motor drives are moved back to the "unlock" position.
Important!
Emergency operation:
If the central locking system fails due to an electrical fault, the driver's and passenger 5 doors can be unlocked via the door locks even when arrested.
Defect information:
If one of the following defects occur:
- driver's Or passenger's door is not locked Or unlocked,
- ZV motor drive for driver's Or passenger's door faulty,
- rear lid is not locked,
this is signaled to the operator by the following sequence:
- After locking, the vehicle is automatically unlocked once again. This function is carried out on the second unlocking attempt.
Or
- After unlocking, the vehicle is automatically locked once again. This function is carried out on the second unlocking attempt.
Repeat lockout:
If the central locking system is operated more than 30 times within 2 mm, the entire system is switched oft by a repeat lockout function for approx. 2
minutes. This function prevents overloading of the ZV motor drives.
Crash sensor:
(Inertia switch) installation location: Under left rear seat. The crash sensor is effective only when the ignition switch is set to R or 15 (position 1 or 2). At the point of impact, the sensor briefly switches a ground signal to the general module. The vehicle is unlocked/released, the interior lights are switched on (only in switch position automatic interior lights), the hazard warning system is activated (only if a crash and alarm sensor is installed) and the central locking system (ZV) is disabled.