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Mod ID1278
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Linkhttps://dev.evilution.co.uk/mod/roadster-transmission-pin-out.htm Copy to ClipboardTransmission (Gear Box) Connections
If you are experiencing the 3 Bar error on the speedo display, there is a very high chance that the issue lies with the wiring loom to actuators and sensors that control the gearbox. A visual inspection of the wiring loom often shows up the issue but not always.
Movement of the wires can cause cracks in the sheathing which allows water in. The water and electricity increases the speed of corrosion to the copper core of the wire. However, this damage may not be visible from the outside.
Continuity Testing
The best way to test a wire’s integrity is to use a multimeter on continuity mode. This is where you hold a probe at each end of the wire and the meter will tell you if there is a connection.
Most multimeters will have 2 continuity modes. One will tell you the resistance of the connection and the other will just beep if it senses a connection. Start with the simple beep mode at first.
| Transmission Controller | Pin Connection | Wire Colour | Connects To | Purpose |
| Gear Change Motor | 1 | Green | ECU Plug 2, Pin 3 | Motor |
| 2 | Green | ECU Plug 2, Pin 33 | Sensor + (voltage) | |
| 3 | Yellow | ECU Plug 2, Pin 14 | Sensor B Output | |
| 4 | White | ECU Plug 2, Pin 51 | Sensor – (ground) | |
| 5 | Yellow | ECU Plug 2, Pin 15 | Sensor A Output | |
| 6 | Blue | ECU Plug 2, Pin 1 | Motor | |
| Clutch Actuator | 1 | Green | ECU Plug 2, Pin 43 | Sensor – (ground) |
| 2 | Yellow | ECU Plug 2, Pin 24 | Sensor B Output | |
| 3 | Yellow | ECU Plug 2, Pin 4 | Motor | |
| 4 | Yellow | ECU Plug 2, Pin 23 | Sensor A Output | |
| 5 | Blue | ECU Plug 2, Pin 75 | Sensor + (voltage) | |
| 6 | Yellow | ECU Plug 2, Pin 5 | Motor | |
| Gear Position Sensor | 1 | Blue | ECU Plug 2, Pin 79 | Sensor + (voltage) |
| 2 | Yellow | ECU Plug 2, Pin 19 | Sensor Output | |
| 3 | White | ECU Plug 2, Pin 60 | Sensor – (ground) | |
| Gearbox RPM Sensor | 1 | Red | ECU Plug 2, Pin 11 | Sensor + (voltage) |
| 2 | White | ECU Plug 2, Pin 30 | Sensor Output |
Continuity Tested OK
OK, put the multimeter in the other continuity mode or resistance measuring mode. Test all of the connections again but pay close attention to the figures show on the meter. It’s very possible to have a wire that’s corroded enough to create high resistance but pass some voltage. A tiny pass through of voltage by the meter will cause the beep continuity mode to make a noise.
However, if the wire is corroded and resisting the voltage, it may not be enough to run the motor or sensor correctly. Jot all of the resistance figures down. If any are particularly high, you may have a problem on that wire.
Stress Testing
If you don’t have a multimeter (they are very cheap so you should own one) then you can make a tester. If you get a 12v battery and 12v bulb, or a 9v PP3 type square battery and a 9v bulb (don’t use an LED), You can put the wire that you are testing into a circuit and pass the voltage to the bulb.
Because of the amperage required, if there is a resistive point in the wire, the bulb should be more dim. Alternatively, the wire could get hot at the corroded point and melt the sheathing. If you have a thermal imaging camera, you can see the problem.
Fixing A Corroded Wire
Once you have discovered the problem wire, cut the wire and splice in a replacement. Make sure to protect the connections with heatshrink and run the new cable safely.