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There are many different variations of SAM unit for the fortwo 451. As and when we get more SAM units to investigate, we will update this page with more information. For now, all of the information on this page is based on a 2009 451 MHD with the following part number:

A451 540 2050

In the same way as for the fortwo 450 (mk7) and Roadster, the SAM comprises two sections. The main I/O relay board joins all the connectors with the fuses and high current relays. This is folded into 3 sections. Attached to this is a smaller microprocessor board which does all the clever stuff.

As this page was taken from a working car, we have not separated the microprocessor board from the I/O board. Attempting to have done so might have ruined the unit!

The relays on the centre section of the I/O board are arranged as follows:

Relay CodeRelay FunctionMakeComments
K1 Rear window and wing mirror heated elements. OMRON G8PE-1A4 Wing mirrors optional at factory. Heated rear window available on both coupes and cabrios.
K2 Electric soft top. OMRON G8N-1H Two relays: one for up and the other for down.
K3 Starter motor. OMRON G8PE-1A4  
K7 Engine master. OMRON G8PE-1A4 Injection valves, ignition coils etc.
K9 SE drive (gear change system). OMRON G8PE-1A4  
K10 Front wipers. OMRON G8N-1H  
K13 Rear wiper. Fujitsu FBR51ND10-W1 Not applicable on Cabrios.
K820 Horn, intercooler fan. OMRON G8NW-2H Intercooler - only applicable on Turbo / Brabus Models
K830 Central Locking. OMRON G8NW-2H  
K840 Rear boot lock. Omron G8N-1H Only applicable on Coupes


Turning the SAM over, reveals more relays. Relays K4, K12 and K14 are slightly obscured by the attached microprocessor board.

Relay CodeRelay FunctionMakeComments
K4 Electric Fuel Pump. OMRON G8N-1H  
K6 High Beam Headlights. Fujitsu FBR51ND10-W1  
K8 Dipped Beam Headlights. OMRON G8N-1H Two separately fused and relayed circuits for resilience.
K11 Electric Windows, Interior Fan. OMRON G8PE-1A4  
K12 Front and rear side lights, numberplate lights, interior backlighting. OMRON G8N-1H  
K14 Fog Lights. Fujitsu FBR51ND10-W1  

The 'K' reference numbering system matches that used by the fortwo 450 and Roadster. You may have noticed that 'K5' does not appear in the above SAM. 'K5' on the fortwo 450 and Roadster is for the exhaust catalytic converter pre-heater unit. The fortwo 451 MHD is not equipped with one of these and so the relay (and reference) has been dropped.

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