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 (LS-CAN).
The control panel on the driver's side has control buttons for adjusting the door mirrors, window lift mechanisms and the button for activating child-proof locking (not C70).
The control panel on the passenger side has control buttons for the power window mechanism.
There is also a button for locking and unlocking the central locking by the inner door handle on each side.
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 following only applies to the S40/V50:
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.