Fully Automatic Convertible Top

E36 FULLY AUTOMATIC CONVERTIBLE








The 328 Convertible top drive has been redesigned for the 1997 model year. The top is now fully automatic in operation and requires no more than pushing the button to fully lower or raise the top. The one remaining manual feature of the 96 model year automatic top operation - that of unlatching the top from the windshield frame and pushing it past the tension point by hand - has been fully automated with the addition of the following components.
- Redesigned top switch
- One additional electric motor - for unlocking the top and raising it past the tension point.
- Redesigned latch assemblies at the windshield frame
- Additional electronic circuitry in the control module
- Two convertible top lock/drive assemblies.
- Two additional micro-switches.
- Additional linkage rods








The top lock release motor is installed behind the interior headliner at the front bow. The top lock/drive assemblies are positioned on the left/right sides and are driven through two flexible cables.








Two additional microswitches (S7 & S8) are positioned on the left side top lock drive assembly. Both switches are fixed in position and require no adjustment.








The top switch is positioned in the center console as on the previous system.
The switch contains an LED that flashes when the top is not completely closed.

TOP OPERATION

When the top switch is pressed to lower the top the following occurs:
1. The top lock motor is powered in the unlock direction.
2. The left and right side locks are mechanically released via the drive cables.
3. Microswitch S7 closes indicating the top is unlatched from the windshield frame.
4. Once the locks are completely released, the top lock motor continues to run lifting the front bow above the tension point via the tension rods.
5. As the front bow passes the tension point, micro switch S8 closes. The top lock motor switches off and the top motor is switched ON.

The remainder of the top operation is the same as the previous system. The rear tension bar is raised to the vertical position. The storage compartment cover is opened and the top is lowered into the storage compartment. The storage cover is then closed.


NOTE: Microswitch S4, of the previous semi-automatic E36 top has been deleted. This switch is not required since the manual operation of pushing the top off the tension point in a semi-automatic system is now handled by the top lock motor and signalled via S8.

The new top switch LED flashes anytime the top is not fully closed and locked to the frame. However, the LED will not flash when the top is fully stowed in the top compartment with the lid closed. The control module determines this by the top lid position hall effect sensor.

COMFORT CLOSE FEATURE: The fully automatic top incorporates the comfort close feature which is activated from the driver's or passenger's door position. Holding the key in the lock position automatically closes and locks the top and windows from outside.

INITIALIZATION: The initialization procedure is unchanged from the previous system. The systems new top lock motor will require manual locking/unlocking using the hex key from the tool kit (similar to manually closing a sunroof).

BATTERY: The convertible's body design causes inherent body vibrations to oscillate in the area of the trunk. In a sedan or coupe, the vibrations are transferred to the roof. The E36 convertible uses the mass of the battery for a vibration dampening system via the battery tray. Therefore, the E36 convertible requires a unique battery which is designed for an environment of high vibration. A battery not designed for this environment will tail due to the vibration. Using the EPC or parts microfiche, always check the part number of a battery being installed in a convertible.

Battery voltage must be above 10.5 volts for proper system function. When conducting service procedures, always connect a battery charger to vehicle.

DIAGNOSIS:







ADJUSTMENTS







The following adjustments are possible on the new lock mechanisms of the fully automatic top.

Tension Rods. The tension rods (1) move simultaneously with the latch lock when the motor is either locking or unlocking the top.

Unlocking: The rods produce the tension on the pivot of the top to raise the front edge of the top off the window frame.

Locking: The rods pull the top into the seal allowing the latches to grab the latch plates in the window frame.

"A" measurement = 205.5 mm. This measurement ensures correct system function. The measurement is taken from the pivot rivet (3) where the rod is attached to the latch mechanism to the center of the ball pin (2).


Latch Mechanism Mounting Adjustments.













The basic adjustment of the latch mechanisms to the top frame is critical to ensure proper sealing of the top to the windshield frame to prevent moisture infiltration and wind noise.

There is a height adjustment screw that pivots the front edge of the mechanism either closer or further to the window frame when closed.

Specific screws must be removed and loosened to access the pivot screws.

Refer to the repair manual in the TIS for complete measurement and adjustment procedures