The SAM is standard on all Roadsters and fortwos from 2003 onwards. This unit replaced the ZEE unit (present on earlier models) and intended to consolote all the cars electrical inputs and outputs into one unit.
Please note that you should never open a working SAM as you risk permanently damaging the unit. We disected a broken SAM to see exactly what it comprised.
Several different versions of the SAM were developed. Generally, the difference are minimal with some upgrades to the software and processing functions. The SAM version can be seen on the front label. In this case, we were looking at a V.11 SAM. This is the front view of the unit which can be seen from the footwell. In this case, all fuses have been removed.
The rear of the SAM is as follows. You can see all the wiring connectors along with the four large fuses for ESP, EPS, CAT preheater and ignition.
The SAM is secured with 3x T10 torx screws from the front.
The case is then held together with serveral clips around the perimeter.
This allows the front face to be removed revealing the PCBs.
To remove the back case, the four large fuses were removed.
The main PCB board is wrapped around a central plastic frame. Note that there is a separate processor module attached to the main board.
This can be easily unwrapped by freeing the black clips from around the PCB.
The board will then unwrap as follows:
The plastic centre panel can now be removed.
The processor board was unsoldered from the main PCB. The layout of the main board is shown below. Note that this board does not contain any sensitive components. In the Roadsters, if this board gets wet, there will simply be some spurious activity as relay inputs are shorted. Nothing will be permanently damaged.
The processor board is the 'intellegent' part of the SAM. If this board gets wet, serious damage can occur which is likely to result in SAM replacement. It is this board that contains the SAM speaker which creates the indiciator 'tick-tock' and the warning beep.
Where the PCB folds around the central plastic panel, it is common to see some fraying on the backing. It is a common mistake to think that this means the SAM is broken. The copper tracks are on the other side and are thick enough to withstand a few folds.
However, excessive folding will cause fatigue and the tracks will start to break. You can see the weak points starting to develop below.