Front Sunroof Operation

When the ignition switch is in position II, an enable input is sent from the BCU pin C0661-9 on a WG wire to pin C0785-10 on the sunroof ECU. When the enable input is present the power feed from pin C0785-3 is made available by the logic circuits in the sunroof ECU.

The sunroof ECU is earthed from pin C0785-2 on a B wire via splice joints A14 and A15 to earth header C0018.

Front sunroof tilt detection
The front sunroof motor is connected to pin C0784-8 on the sunroof ECU by a U wire. An input to the sunroof ECU via this connection forms a sunroof tilt input to the sunroof ECU.

Front sunroof - open function
When the front sunroof switch is set to the open position, an earth path from pin C0784-2 to the front sunroof switch on a GK wire is completed. From the front sunroof switch the earth continues to earth header C0018 via splice joints A14 and A15. The sunroof ECU logic circuit monitors a current flow from pin C0784-2. This current flow forms the 'open' input to the sunroof ECU, and the ECU logic supplies a power feed to pin C0785-5.

The feed flows from pin C0785-5 on the sunroof ECU to the sunroof motor on a P wire. The front sunroof motor is earthed on a B wire via splice joints A14 and A15 to earth header C0018.

The sunroof motor drives the sunroof mechanism towards the open position. When the sunroof switch is released, the earth path via the sunroof switch is interrupted and the 'open' input to the sunroof ECU is lost. The sunroof ECU logic circuits remove the power supply to pin C0784-2, this removes the power supply from the sunroof motor.

Front sunroof - close function
When the front sunroof switch is set to the close position, an earth path from pin C0785-7 of the sunroof ECU to the front sunroof switch is completed on a GR wire. The front sunroof switch is earthed via splice joints A14 and A15 to earth header C0018 on a B wire. The sunroof ECU logic circuit monitors a current flow from pin C0785-7. With this current flow forming a close input the sunroof ECU logic supplies a power feed to pin C0785-1.

The feed flows from pin C0785-1 of the sunroof ECU to the sunroof motor on a W wire. The front sunroof motor is earthed on a B wire via splice joints A14 and A15 to earth header C0018. The sunroof motor drives the sunroof mechanism
towards the close position.

When the sunroof switch is released, the earth path via the sunroof switch is interrupted and the close input to the sunroof ECU will be lost. The sunroof ECU logic circuits remove the power supply to pin C0785-1 this removes the power supply from the sunroof motor.