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This guide is only applicable to the 698cc fortwos manufactured between 2003 and 2006. Earlier models did not have a SAM unit and so the arrangement is slightly different.

All the fortwo electrical relays are located in or adjacent to the SAM unit. The relays within the SAM are non-serviceable but are unlikely to fail over the life of the car.  All of the relays within the SAM unit are common to fortwos and Roadsters but some of them are not used, depending on the car.

The relays located within the SAM unit on the main I/O board are as follows:

Relay CodeRelay FunctionMakeComments
K1 Rear window and wing mirror heated elements. Tyco V23076-A3001-C132 Wing mirrors optional at factory.
K2 Electric soft top. Fujitsu FBR512ND10-W1 Dual relay for up and down.
K3 Starter motor. Tyco V23076-A3001-C132  
K4 Fuel pump. Fujitsu FBR51ND10-W1  
K5 Exhaust catalytic system pre-heater pump. Tyco V23076-A3001-X019  
K6 Full beam headlights. Tyco V23072-C1061-A408  
K7 Engine master. Tyco V23076-A3001-C132 Injection valves, ignition coils etc.
K8 Dipped beam headlights. Tyco V23072-C1061-A408  
K9 SE drive (gear change system). Tyco V23076-A3001-C132  
K10 Front wipers. Fujitsu FBR51ND10-W1  
K11 Fan blower, electric windows, heated seats Tyco V23076-A3001-C132 Heated seats optional at factory. This relay switches when key is in position 1.
K12 Front & rear side lights, interior console backlights. Fujitsu FBR51ND10-W1  
K13 Rear wiper. Fujitsu FBR51ND10-W1 Not applicable on Cabrios.

The relays on the microprocessor unit contained within the SAM are as follows:

Relay CodeRelay FunctionMakeComments
K820 Horn, intercooler (or chargecooler) fan NAiS ACT512 B02 Chargecooler - only applicable on Brabus Ultimate / Blackstar
K830 Central Locking NAiS ACT512 B02  
K840 Rear boot solenoid Omron G8N-1S  

The number of accessible relays will depend on the functions fitted to your fortwo at the factory.  All fortwos we have seen are equipped with the relay for fog lights even though the actual fog light units may not have been installed.

The complete relay arrangement is as follows:

Relay CodeRelay FunctionComments
K52 Fog lights. Optional (blue base frame).
N25/1 Left heated seat module. Combined relay and controller.
N25/2 Right heated seat module. Combined relay and controller.

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