Driver Door Module (DDM) / Passenger Door Module (PDM)
The driver door module (DDM) (3/126) and passenger door module (PDM) (3/127) are identical in appearance. The only difference between the two units are the software downloaded into them after installation in the vehicle. There are also different control panels connected to the control modules. The side on which each control panel will be positioned is determined by whether the vehicle is left or right-hand drive. The door control modules communicate with the central electronic module (CEM) via the low speed side of the CAN network.
The control panel on the driver's side has switches for locking and unlocking the central locking, for adjusting the door mirrors, operating the window lift mechanisms and switches for activating the child-proof locks, if installed. The driver's panel can also have switches for activating electric folding mirrors. The switch for locking and unlocking the central locking is directly connected to the driver door module (DDM) while the other switches on the panel are connected in series via LIN.
The control panel for the passenger side has switches for locking and unlocking of the central locking and a control button for the window lift. The switch for locking and unlocking the central locking and the control button for window lift are directly connected to the passenger door module (PDM).
The door control modules are directly connected to the lock unit in each door. The door control modules lock and unlock the door on receipt of a command from the central electronic module (CEM). The door control modules can only unlock the door on receipt of a signal from the central electronic module (CEM).
The driver door module (DDM) and passenger door module (PDM) communicate with the control module in the rear door on the same side of the vehicle via a serial interface (LIN).
The door control modules forwards the received signals from the CAN network to the rear door control module. The signals forwarded are the locking and unlocking commands. The door control modules also forward signals from each rear door control module on the CAN network. The signals that are forwarded indicate the position of the lock motors for child-proof and central locking.
The door control modules have diagnostic functions which monitor the function of the buttons to check that they have not stuck and that the relays are intact.
The control modules are powered via the rear fuse box and grounded in the body.