I heard that when fitting the LET to an astra you should cut one of the wires on the car to ECU wiring plug.
Does anyone know what this wire does and what colour it is?
I have fault code 42 come up every time I drive faster than about 40mph and it stays on until I reset the ECU.
I have tested the 1t gear switch and found it to be OK.
I have also tested the 1st gear switch wiring plug, 5 volts on one pin and GND on the other (as expected).
In my opinion it must be something else and the only other thing I can think of is someone mentioning the wire you need to cut...