General
SINGLE PANEL SUNROOF (SHD)
OVERVIEW
All current single panel sunroof (with the exception of 318ti cloth foldable sunroof) incorporate the "low noise vent" feature. When the sunroof is driven to the vent position (rear of panel up), the inside headliner moves rearward approximately 120 mm. This provides cabin ventilation with little noise.
A water channel is incorporated into the sunroof assembly. It automatically rises when the sunroof panel is in the vent position and prevents water from entering the interior during braking.
VENT POSITION
CLOSED
FULLY OPEN
There are currently two types of sunroof panels available; Steel or Glass. Service Procedures are different for each type. Always follow the Repair Manual procedures for the type being services.
Sunroof provide similar functionality when it comes to their various positions and features. When looking closer, their operation and service procedures are in some cases quite unique.
SUNROOF FEATURES
Anti Trap: This feature uses a hall sensor to detect obstructions while the sunroof is closing (pulse frequency slowed down) in the automatic close function. The anti-trap feature is shut down prior to full closing (4mm from full closed) to allow the sunroof to seat into the seal.
Caution: The anti-trap feature is not functional when the switch is held in the manual close position.
Unloading: If the sunroof is running during engine starting, the sunroof will be deactivated. This function is to provide maximum starting power to the engine starter motor. The SHD receives the consumer cut off signal via the K or P bus or dedicated wire.
Panel Sealing Function (E46 Only): The E46 sunroof includes a mechanical feature designed to improve panel sealing to minimize wind noise. When closing from the vent position, the panel moves quickly up and down close to the fully closed position. This is due to the mechanism design but helps seat the seal evenly around the perimeter of the panel to optimize sealing.
COMPONENTS (GENERAL)
MOTOR/DRIVE CABLES
The sunroof assembly utilizes two separate bowden cables sheathed by metal tubes. One cable is used to drive the headliner, the other drives the roof panel mechanism.
The sunroof motor drives the sunroof cables via a gear connection.
MOTOR CONTROL
Sunroof motors of the E36 (up to 11-95 production), the California roof of the 318ti and the tilt only roof of the M coupe are manually switched power controlled motors.
Refer to ETM for specific power supply and control circuitry.
Note: Refer to Sunroof Motor for information on sunroof motor installation.
The motors of all other sunroof Systems are connected with a sunroof module, giving them the name "Motor/module". The module controls the sunroof motor based on signals it receives:
The motor itself (hall sensor - anti-trap feature).
The sunroof switch.
ZKE - General Module.
- The comfort closing feature when the key is held in the lock position in one of the door lock cylinders.
- Unloader signal. This signal informs the sunroof motor module to stop running the sunroof motor when the GM receives a KL 50 start signal.
These signals are either individual circuits as on the E36 or via the K or P bus for the E38, E39 or E46 vehicles
The module also provides diagnosis information to the General Module of ZKE for the E38. E39 and E46 vehicles.
SUNROOF PANELS AND HEADLINER
The steel panel is made of body gauge sheet metal on a support frame. Except for the E31, all steel panels are attached to the drive mechanism via a rear support/adjustment carriage rail.
The headliner of these systems is automatically driven along with the sunroof panel when fully open and automatically driven closed when the sunroof is closed.
When the sunroof panel is placed in the vent position, the headliner is driven back a distance of approximately 12O mm by the drive cable.
The headliner is linked to the drive cable on the driver side of the vehicle by a "link arm".
On early (<11/94) E36 sunroof a "rotary catch" connects the headliner to the drive cable.
When the vent position is selected the Link Arm engages the inner cable and the headliner panel is moved rearward towards the vent position.
Glass Panel Sunroof & Headliner
The glass panel is made of 5mm break resistant glass. The rear support/adjustment carriage rail of the steel panel system is not used with the glass panel. The glass panel is attached to the sunroof drive mechanism by four or six self tapping screws (system dependent). The mounting screws are also used to adjust the glass panel height.
The headliner for these systems is made of aluminum. It contains a small recessed grab handle at the front for manual operation.
When the sunroof is moved to the vent or open position, the headliner moves to the same positions as the steel panel system.
The link arm of a glass panel system is different than that of the steel panel system. The closing catch found on a steel panel sunroof link arm is deleted from the link arm of glass panel sunroof.
This modification allows the manual opening of the headliner when glass panel is closed as well as allowing the glass panel to close without automatically sliding the headliner forward.
The headliner is however moved forward slightly by the drive mechanism to reveal the recessed handle for manual closing.
With the exception of the E46, a rubber "Gaiter" (i.e.: bellows in repair manual) is attached to the sunroof drive assembly and glass panel on both sides to conceal the drive linkage when the panel is in the vent position with the headliner open.
The "Gaiter" must be removed to access adjustments.