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Difficulty
Credit
Evilution
Mod ID
463
Cost
£0
For
450 Fortwo 600cc
450 Fortwo 700cc
452 Roadster 700cc
450 Fortwo 700cc
452 Roadster 700cc
The idea is very simple. On the other end of the gear stick is a magnet, as the magnet
moves over a sensor it increases the amount of current passing through it.
At a certain level the circuit switches and sends a data stream to the ECU.
The ECU interprets the code and changes the gear up or down.
Can The Up And Down Be Reversed?
It has been possible previously to swap the + and - by using a Smartronics gear shift board.
These are now unavailable so another method needed to be found.
There are many rumours flying about that the connections to the switches (Hall effect sensors)
could just be swapped over and therefore reversing the + and -.
On further inspection I discovered this to be false, take a look
The next idea was to route the hall effect sensors output to the other sensor and
vice versa but this idea had its drawbacks as PCB tracks would have to be cut. So...
After looking through the wiring diagrams and the pin ins and out of the ECU I discovered that
'gear up' and 'gear down' used a separate line each so there was no special code being transmitted
to the ECU, it was a simple switching voltage.
That means there doesn't seem to be any good reason why the up wire and the down wire
couldn't be swapped over to give the desired effect. Infact a switch could be installed,
this would give the driver a choice between the two modes.
How Do I Do It Then?
You will have to remove the SE Drive to access the wires, this isn't totally necessary but
easier than removing the carpet to gain access to the wires on top of the centre tunnel.
Look at the main connection going to the bottom of the SE Drive, it is a 12 way connection joining straight to the PCB. From that connection you are looking for...
-
connection 4 - Blue/Red wire - This is shift UP.
-
connection 8 - Blue/Grey wire - This is shift DOWN.
In my mind, there is no reason why you cannot cut these wires and swap them over.
Does It Work?
I don't know, I am one of those people who is happy with pushing the gear stick forwards for up so I have no need to test it out. Test it out and please let me know how you get on.
Obviously if your car explodes into small bits, don't blame me.
Switching From One Mode To Another
Assuming of course that the above works, switching from one to the other should be easy.
What you need is a DPDT (Dual Pole, Dual Travel) switch. This design can switch two circuits similtaneously without either circuit meeting. The switch connects the centre connections of the switch to either of the outside two pairs but never both.
The grey boxes indicated the connection inside the switch.
So to conclude, the picture below shows the correct wiring for the DPDT switch. The red lines indicate the connections made inside the switch. 1 & 6 and 2 & 5 are bridged by wires.
The left hand image is the switch in the down position:
The blue/red 'gear up' wire connects to pin 3, internally, the switch connects it to pin 1.
Pin 1 is connected to the red/blue ECU 'gear up' wire. The bridge from pin 1 to pin 6 is an electrical dead end so does not become part of the circuit.
The blue/grey 'gear down' wire connects to pin 4, internally, the switch connects it to pin 2. Pin 2 is connected to the red/grey ECU 'gear down' wire. The bridge from pin 2 to pin 5 is an electrical dead end so does not become part of the circuit.
The right hand image is the switch in the up position:
The blue/red 'gear up' wire connects to pin 3, internally, the switch connects it to pin 5.
Pin 5 is bridged by a wire to pin 2 which connects to the red/grey ECU 'gear down' wire.
The blue/grey 'gear down' wire connects to pin 4, internally, the switch connects it to pin 6. Pin 6 is bridged to Pin 1 by a wire which connects to the red/blue ECU 'gear up' wire.
Conclusion
As you can see, with the switch in the down position, the lines are swapped over.
This should cause the reversal of the gear change. No guarantees of course.
This is 100% theory until one of you good people test it out.
If you want your name up here saying you have tested it let me know how you got on.
SE Drive Wiring Connections
Pin Number Wire Colour Connection 1 Pink/Blue Charcoal filter shut off 2 Grey/Red Reverse light 3 White/Grey ECU pin 85 4 Blue/Red ECU pin 95 gear up 5 Green/White or Grey/Blue ECU pin 84 6 Blue Power 7 No Connection No Connection 8 Blue/Grey ECU pin 87 gear down 9 Blue/Black or Blue/Green ECU pin 93 10 Brown ECU pin 96 11 No Connection No Connection 12 No Connection No Connection
