Door Locks: Description and Operation
The New Beetle offers a comprehensive list of standard comfort and convenience features that have often been optional equipment on other models.
Although many technicians are experienced in the operation of these systems, new technology controls their operation, and On Board Diagnostic through the VAG1551 simplifies troubleshooting.
New Beetle standard equipment:
- Central Locking with Radio-frequency Remote Control.
- Heated Power Mirrors.
- Anti-theft Alarm System.
- Interior Light Control.
Optional power accessories:
- Power Windows with one-touch down/up and Pinch Protection.
- Convenience-open for Power Windows.
1 A-pillar Connector Station
2 Switch for Window Regulator in Passenger Door -E107-
3 Antenna Wire for Central Locking and Anti-theft Warning System -R47-
4 Switch for Interior Lock Passenger Side -E198-
5 Door Control Module Passenger Side -J387-
6 Lock Unit for Central Locking Passenger Side -F221-
7 Mirror Adjustment Switch -E43-
Mirror Selector Switch -E4-
8 Switch for Interior Lock, Driver Side -E150-
9 Motor for Remote Unlock Rear Lid -V151-
10 Lock Unit for Central Locking, Driver Side -F220-
11 Door Control Module Driver Side -J386-
12 Switch for Remote Unlock, Rear Lid -E188-
Switch for Remote/Fuel Tank Door -E204-
13 A-pillar Connector Station
14 Left Front Window Switch -E40-
Right Front Window Switch, Driver Side -E81-
15 Central Control Module for Comfort System -J393-
16 Hood Alarm Switch -F120-
17 Motor for Fuel Tank Lid Unlock -V155-
Although these features can be found on other Volkswagen models, what is new on the New Beetle is the way that the comfort and convenience systems are linked together.
Central Control Module Location:
Central Control Module With Power Windows:
Central Control Module Without Power Windows:
The system includes the Central Control Module mounted under the instrument panel near the steering column, and two Door Control Modules mounted with the power window motors.
The Central Control Module and the Door Control Modules communicate with each other using a Controller Area Network bus (CAN-bus). Vehicles not equipped with power windows use a different Control Module.
The Central Control Module controls the following:
- Interior Light Control.
- Anti-theft Warning system.
- Radio-frequency Remote Control for Central Locking.
- Electrical system interface.
The Door Control Modules control the following:
- Central Locking.
- Power windows.
- Power Mirror Adjustments.
CAN-bus
To reduce the number of wires used on the vehicle, and to increase reliability, many electrical functions are accomplished using serial data transfer via a Controller Area Network bus (CAN-bus).
Similar to a telegraph system, this process converts information into a series of pulses representing coded data messages that can be understood by other components.
There are several advantages to using a CAN-bus to control the operation of the comfort and convenience features.
Wiring is greatly simplified. Only short runs of wire are needed between the Door Control Modules and the components in the doors. Only 10 wires pass between the door and the A-pillar, where up to 30 wires were used to control these components on current Golf/Jetta models.
Data transfer
Data transfer is structured in a very simple way. Each Control Module sends a message every 20 ms. This message contains the status data and commands. All of the Control Modules on the CAN-bus are informed of the current operating Status of the system at these intervals.
These signals are binary coded messages and although the control Modules receive the same signals, only those programmed to recognize specific messages respond. Because the system is bi-directional messages can travel back and forth between all Control Modules to report on their status.
Although just a single wire is sufficient to transmit the data, two wires are used for greater resistance to interference. Digital messages are transmitted along both cables simultaneously, but inverted to one another. When the signals are analyzed by the Control modules, the voltage of the inverted signal is subtracted from the other signal.
This makes it possible to distinguish the normal signals from interfence since an interference spike would travel along both wires with the same polarity.
The messages, divided into seven fields, include a status field to identify their importance. If two messages require transmitting at the same time the message with the highest priority is transmitted first.
Power windows
Power windows are available as optional equipment, and are controlled by the Door Control Modules. These are part of the comfort system, and built into the Window Motors. The motor can be removed without removing the carrier assembly.
The power windows are operated by a five-position switch. This system also has one- touch up and one-touch down functions.
The power windows can be raised or lowered with or without the one-touch feature.
To raise or lower the window, move the switch to the first detent and hold until the window reaches the desired position.
To fully raise or lower the window using the one-touch feature, move the switch to the second detent and release.
Pinch Protection only operates during the one-touch up function. If an obstruction prevents a window from closing, the window motor reverses itself. This feature is only operational with the interior window switches.
If a window binds while being closed using the one-touch up function, the Pinch Protection feature may prevent it from fully closing (a build-up of ice or dirt on the window or door frame may cause this to happen). Closing the window a second time, the window will stop at the obstruction but will not retract. Remove any obstruction, then close the window.
Each motor also includes a position sensor. The Door Control Module uses this signal to determine window-closed and window-open positions. The information from the sensors is stored in memory for use with the one-touch function.
If the power supply to the Door Control Module is lost, the one-touch function will be deactivated. To reset the one-touch function, run the window all the way down, then up completely. The Control Module will lock the sensor input position into memory, and the one-touch function will be restored.
The power windows remain functional for 10 minutes after the ignition is switched off, provided that a door is not opened. The one-touch up function is deactivated when the ignition is switched off.
Interior Light Control
The Central Control Module for Comfort System -J393- controls the switching and dimming of the interior lights. It also limits the length of time the lights remain on if the doors are left open with the ignition switched off.
The Central Control Module for Comfort System -J393- receives signals from the Door Contact Switches and the Rear Lid Contact Switch. They are microswitches built into the lock assemblies.
If the interior light has been switched on, the control module will switch it off again after one hour. If the light is switched off, then on again, the sequence repeats.
Interior lights will be switched on for a maximum of 30 seconds, then dimmed to off, if the control module receives any of the following inputs:
- Car unlocked with key or remote control.
- One door opened from inside.
- Ignition key removed from ignition with doors closed.
When the doors are locked, or when a door is closed after the doors have been locked, the interior lights are switched off.
If an accident deploys an airbag, the Airbag Control Module -J234- sends a signal to the Central Control Module for Comfort System -J393-.
- The interior lights are switched on for 10 minutes (if the light switches are set to door contact position).
- The doors are unlocked.
- The emergency flashers are activated.
Rear lid and fuel tank lid locks
The Rear Lid is always mechanically locked. It can be opened electrically using the switch in the driver's door, or the remote transmitter. In the event of an electrical system malfunction, it can be opened using the key.
The trunk release switch, located in the driver's door panel, signals the Central Control Module for Comfort System -J393-. The relay supplies current to the motor to unlock the rear lid.
The rear lid lock cylinder and lifting handle are located under the VW emblem on the rear lid. The emblem swivels to the side to reveal the lock and handle. As the emblem moves the handle pops out of its recess. When the key is turned, a microswitch in the lock is activated by a cam on the lock cylinder.
The microswitch sends a signal to Central Control Module for Comfort System -J393-, which activates the Relay -J398-, switching current to unlocking motor.
CAUTION!
The rear lid handle does not unlatch the rear lid. Only the switch in the driver's door, the key in the rear lid lock, or the remote control will open the lid.
The motor for the fuel tank lid lock is powered directly through the switch in the drivers door. If an electrical malfunction prevents the fuel tank lid from opening it can be opened mechanically. Removing a round access panel inside the luggage compartment (right side) reveals the lock cable. Pulling on the cable releases the lock.
Sleep Mode
To reduce current draw from the comfort convenience electronics, a Sleep Mode is programmed into the system. The system draws 150 mA in an active state. When the ignition is switched off, the system goes into a "wait" state.
When all door lock switches are recognized as closed and power window function timers have run out, the Door Control Module sends a "set sleep bit" via the CAN-bus.
Once all Control Modules on the bus recognize the set sleep bits of the other Control Modules, they cease data transfer and go into Sleep Mode.
In Sleep Mode, only the Anti-theft Alarm, Radio-frequency Remote Control, and the Alarm LED are operational. Current draw drops to 7 mA. Any input that requires the system to react, such as a door-open signal from the remote control, results in a wake up command and the system becomes active within 100 ms.
Door lock electronics
The door lock assemblies contain microswitches used to operate the Anti- theft Alarm, Central Locking and Interior Light Control. The switches provide input to the Door Control Modules where their signals are processed and sent out over the CAN-bus. The switches are not replaceable.
The microswitches provide the following signals:
- DOOR OPEN signal.
- LOCK signal.
- UNLOCK signal.
- LOCKED feedback signal.
Central Locking System function
The vacuum-controlled Central Locking System from current Golf/Jetta models has been replaced by electrically operated door locks. Each Door Control Module signals the Central Control Module and the other Door Control Module by way of the CAN-bus when a door is locked or unlocked.
The block diagram shows an example of using the driver's door lock to lock the vehicle, close the windows and sunroof and set the anti-theft alarm.
The Door Control Module, Driver Side -J386- is activated by the Lock Module for Central Locking, Driver Side -F220- when the key is turned in the lock cylinder.
- -J386- checks status of -F220- to determine whether door is closed.
- If closed, -F220- locks the driver's door.
The lock signal is sent over the CAN-bus to the Central Control Module for Comfort System -J393- and to the Door Control Module, Passenger Door -J387-.
- -J387- independently initiates the lock function in the passenger door
- -J393- switches off the Interior Light, and activates the Anti-theft Alarm.
This sequence can be initiated by using the Radio-frequency Remote Control.
The Central Locking System can also be activated using the Switch for Interior Lock, Driver Side -E150- or the Switch for Interior Lock, Passenger Side -E198-. If a door lock button is pressed, only the lock for that door is activated.
The Central Locking System can also be unlocked by the Airbag Control Module. In the event of a collision with enough force to deploy the airbag, the Airbag Control Module -J234- also signals the Central Control Module for Comfort System -J393- to unlock the doors and switch on the interior light.
Central Locking Radio-frequency Remote Control
All New Beetles come with remote control for the central locks. It is built into the Control Module for Comfort System, or the Central Locking System Control Module for vehicles without power windows. The remote control has the following functions:
- Selective door unlocking.
- Locking of both doors.
- Setting of the Anti-theft Alarm.
- Rear lid opening.
- "Panic" function.
Selective unlocking unlocks the driver's door with one press of the unlock button. A second press of the unlock button will unlock the passenger door. If a door is not opened within 30 seconds of an unlock command being received by the Central Locking Control Module or Control Module for Comfort System, the doors will lock again.
The Anti-theft Alarm is set when the doors are locked. Confirmation is by a short sounding of the Anti-theft Warning Horn and a brief flash of the emergency flashers.
Pressing the rear lid button will unlatch the lid electrically.
The "Panic" function will set off the anti-theft warning horn and switch on the emergency flashers.
Remote Control coding
Up to four Remote Control units can be coded for use on one vehicle. There are two procedures available for coding. Codes can be programmed into individual remote controls using the procedures in the Owner's Manual. These procedures require the use of a spare key.
The VAG1551 Scan Tool can be used to program up to four keys at once. Refer to information on "Adaptation" Function 10 under Address Word 46 for the Comfort System or Address Word 35 for Central Locking, in the Repair Manual or the Volkswagen Electronic Service Information System (VESIS).
On Board Diagnostic (OBD)
The Comfort and convenience system for the new Beetle has On Board Diagnostic (OBD) capability using the VAG1551 scan tool. Address Word 46 will provide the following functions:
- 01 - Check Control Module Version
- 02 - Check DTC Memory
- 03 - Output Diagnostic Test Mode
- 05 - Erase DTC Memory
- 06 - End Output
- 07 - Code Control Module
- 08 - Read Measuring Value Block
- 10 - Adaptation
Because there are three Control Modules in this system, Address Word 46 gives a slightly different display sequence. First the Central Control Module for Comfort System information is displayed. It is similar to other Control Module displays.
When the arrow button is pressed, however, "Select function" is not displayed. Instead, the Arrow button advances to the left Door Control Module display, and pressing the Arrow button again goes to the right Door Control Module display. "Select function" is displayed the next time the Arrow button is pressed.
"Automatic Test sequence" Word 00 will print out all three Control module displays before printing the status of DTC memory.
"Check DTC Memory" Function 02 helps pinpoint malfunctions and "Output Diagnostic Test Mode" Function 03 checks the Outputs for proper function.
"Read Measuring Value Block" Function 08 can be used to check all switch functions and the CAN-bus for the Comfort System It will also display system status:
- Locked.
- Unlocked.
- Door OPEN.
Central Control Module With Power Windows:
Central Control Module Without Power Windows:
Although the Central Locking System used vehicles without power windows does not have a CAN-bus, these systems still have On Board Diagnostic capability. "Central Locking" Address Word 35 is used for access to the Control Module.
Refer to the Repair Manual or the Volkswagen Electronic Service Information System for diagnostic procedures using the VAG1551 Scan Tool.