Mod Description
SAM Unit 451 connectionsMod Details
PremiumNo Difficulty Mod ID821 Creditevilution For Linkhttps://www.evilution.co.uk/mod/451-sam-unit-pin-out.htm Copy to ClipboardSo What Is The SAM Unit?
Essentially it is a fuse box with internal relays and a microprocessor that controls almost all of the electrical functions of the car. The processor is flashable so it can
be taught new tricks by way of a TAN code, these tricks include paddle gear shift, auto door locking, automatic gear change, day time running lights, cruise control etc.
What Does SAM Stand For?
Signal Acquisition & Actuation Module.
Where Is It?
It can be found at the top of the footwell, passenger side of a RHD smart city coupe/cabrio, driver’s side of a LHD smart city coupe/cabrio and the drivers side of a Roadster.
What Does It Look Like?
Just a plain boring black box with fuses pushed into the front. Although the SAM units all look the same, the 451 internals are slightly different.
What About The Bits We Can’t See?
The top side is where most of the wiring goes to, there are 10 connections and a positive input. All inputs are labelled. Each circuit has its own earth point around the car.
There Is Something Missing
Damn right, Relays. Most cars have relays in the fuse box, these control the horn, wipers, indicators, lights etc. The relays visible on the smart are for the rear fog light and heated seats.
How Does That Work Then?
No different except in this case the relays are actually inside the SAM unit.
Inside The SAM Unit
Unclip all the plastic clips around the outside
With the top off you see the main fuse connections
With it removed from the box you see the relays and connectors
The board is in 4 parts and is bent around on itself, you can see the back of the tracks look to become damaged. This is normal and ok. It’s just the carrier between the tracks.
PCB 1, 2 and 3 fold open and a flat plastic retainer can be removed.
PCB 4 is populated with the microprocessor…
…and many small relays
No User Serviceable Parts Inside
You can say that again, if you get water in this there is nothing that can be done. There is nothing you can take out or change, everything is soldered directly to the PCBs.
What About Microchips?
There are surprisingly few IC packages inside the SAM unit. The main one however is the Motorola MC9S12DG256C which is a 112 pin 16-bit device composed of standard on-chip peripherals including a 16-bit central processing unit (HCS12 CPU), 256K bytes of Flash EEPROM and a whole load of other stuff that means very little to me. If you want to know more about this chip. Click here.
SAM connections
999cc Smart Fortwo
N11-1 | Wire Colors | Connection | Fuse |
1 | Red Grey | Blower Motor | 4 |
2 | Red Green | MAF, O2 up, Glow Plug, EGR, Cam Solenoid, Pressure Valve | 8 |
3 | Red White | Power Window Control Unit | 3 |
4 | N/C | N/C | N/C |
5 | Red Pink | ESP Control Unit | |
6 | Black Yellow | Alternator | 1 |
7 | Red Blue | Radio | 15 |
8 | |||
N11-2 | Wire Colors | Connection | Fuse |
1 | Red White | Additional Instruments pin1, rain/light sensor pin 1 | 12 |
2 | Red Violet | Cockpit Switch Group pin2 | 28 |
3 | Violet White | ECU pin72 | |
4 | Black Blue | Heated Rear Window | 28 |
5 | Brown | Earth | |
6 | Red Black | Soft Top Relay Close pin8 | 29 |
7 | Blue | AMT Control Unit pin17 | |
8 | Red Blue | Soft Top Relay Open pin8 | 29 |
N11-3 | Wire Colors | Connection | Fuse |
1 | Black Green | Rear Wiper Motor pin2 | |
2 | Black Red | Restraint Control, Yaw Sensor, ESP, Power Steering, Speedo | 18 |
3 | Black Yellow | ECU pin65 | 19 |
4 | Black Grey | Stereo, Heated Seat Module, Wiper Stalk, Mirrors | 20 |
5 | Black Blue | Cigarette lighter socket | 21 |
6 | Grey Yellow | Left Low beam | 22 |
7 | Grey Violet | Right Low beam | 23 |
8 | Red Yellow | Stop Lamp Switch. Rear fog relay (light sensor only) | 24 |
9 | White Black | Right High Beam | 25 |
10 | White Red | Left High Beam | 26 |
11 | Red | ECU pin80 (petrol) | 27 |
12 | |||
N11-4 | Wire Colors | Connection | Fuse |
1 | Red Black | Ignition position 1 | |
2 | Red Blue | AMT Module pin1 and 3 | 30 |
N11-5 | Wire Colors | Connection | Fuse |
1 | |||
2 | |||
3 | Black Blue | Front Wiper Motor pin3 | |
4 | Grey Yellow
Black/Violet |
Front Fog Lights
Day Time Running Lights |
5 |
5 | Yellow | Front Wiper Motor pin4 | |
6 | Green Blue | Rear Wiper Motor pin1 | 5 |
7 | Grey Green | Right Standing Lamp | 6 |
8 | Brown Grey | Left Standing Lamp | 7 |
9 | Red Black | Soft Top Relay, Interior Lamp | 15 |
10 | Red Yellow | Fuel Injector Power | 9 |
11 | Red Grey | Fuel Pump, ECU pin66,73, O2 down, Coil Packs | 10 |
12 | Blue Red | CDI Control Module | |
N11-6 | Wire Colors | Connection | Fuse |
1 | Violet | Starter | 1 |
2 | Red Blue | Diesel Fuel Pump | |
N11-7 | Wire Colors | Connection | Fuse |
1 | Red White | Power Steering Module | 35 |
2 | Red Green | ESP Control Unit | 34 |
3 | Red | Ignition Main Position 0 | |
N11-8 | Wire Colors | Connection | Fuse |
1 | |||
2 | Blue Black | Boot Release Switch | |
3 | Grey Brown | Wiper Stalk pin4 | |
4 | Yellow White | Right Door Rotary Switch | |
5 | |||
6 | |||
7 | |||
8 | |||
9 | Blue Grey | Front Wiper Motor pin2 | 2 |
10 | Grey Blue | Light Stalk pin2 | |
11 | |||
12 | Violet Green | Microwave sensor pin 2, alarm siren pin 3 | |
13 | |||
14 | Green | CAN Low ECU | |
15 | Green White | CAN High ECU | |
16 | |||
17 | Yellow | Wiper Stalk pin5 | |
18 | White Green | Left Door Central Locking Switch | |
19 | Yellow Black | Left Door Rotary Switch | |
20 | |||
21 | Brown/White | Heated mirror relay pin 4 | |
29 | Red Violet | Cockpit ambient illumination (lighting) | |
30 | Grey White | Rear Soft Top Microswitch | |
31 | Violet Blue | Cockpit Switches pin12 Hazards | |
32 | Yellow Blue | Soft Top Microswitch | |
33 | Violet White | Roof Cassette Microswitch | |
34 | |||
35 | Pink Blue | Soft Top Power Switch | |
36 | Pink Yellow | Boot Handle Switch | |
37 | |||
38 | Grey Black | Ignition Position 2 | |
39 | Green | CAN Low to Speedo | |
40 | Green White | CAN High to Speedo | |
N11-9 | Wire Colors | Connection | Fuse |
1 | Black White | Left Headlight Indicator | |
2 | Blue Red | Boot Opening Solenoid | 31 |
3 | Grey White | Transponder Coil 2 (immobiliser antenna) | |
4 | Brown Blue | Front Interior Lamp | |
5 | |||
6 | Yellow Grey | Soft Top Relay pin4 | |
7 | |||
8 | Blue | Cockpit Switches pin13 Tow Sensor | |
9 | Yellow | Light Stalk pin5 | |
10 | |||
11 | Black Green | Right Headlight Indicator | |
12 | Pink | Cockpit Switches pin10 Central Locking | |
13 | Blue Yellow | Cockpit Switches pin8 Front Foglights | |
14 | Violet Blue | Dash Top Pods, rain/light sensor pin 2 (LIN Bus) | |
15 | |||
16 | Black Blue | Cockpit Switches pin11 Unlock | |
17 | Green Blue | Wiper Stalk pin7 | |
18 | Yellow Blue | Rear Fog Lamp Relay pin4 (light sensor only) | |
19 | |||
20 | Violet White | Transponder Coil 1 (immobiliser antenna) | |
21 | Brown Black | Transponder Coil 3 (immobiliser antenna) | |
22 | Green Black | Luggage Carrier/Base Rack | |
23 | Grey | Footwell Ambient Illumination (lighting) | |
24 | Red Black | Transponder Coil 4 (immobiliser antenna) | |
25 | |||
26 | |||
27 | |||
28 | |||
29 | |||
30 | Pink Black | Horn Button | |
31 | |||
32 | |||
33 | White Black | Heater Air Conditioning Unit | |
34 | Yellow Red | Light Stalk pin | |
35 | Violet Green | Light Stalk pin4 | |
36 | Green Red | Wiper Stalk pin1 | |
37 | Grey | Cockpit Switches pin9 Rear Fog Light (light sensor only) | |
38 | White Red | Light Stalk pin6 | |
39 | Black Brown | Light Stalk pin7 | |
40 | Red Green | Wiper Stalk pin10 | |
N11-10 | Wire Colors | Connection | Fuse |
1 | Brown | Earth | |
2 | White | Aircon Compressor | |
3 | Red Blue | Coolant Radiator Fan | |
4 | Grey Yellow | Central Locking Door Open | 31 |
5 | Pink | Central Locking Door Closed | 31 |
6 | Blue | Horn | 31 |
7 | Yellow | Intercooler fan | 14 |
8 | |||
N11-11 | Wire Colors | Connection | Fuse |
1 | 12 Volt SAM Power In | 33 |