No need for Tech 2 or any sort of code readers just to read fault codes, most Vauxhall dealers don’t know about this....
Want to read the Code well first
Take a deep breath get your car keys and get a pen and paper
When you get into the car you know the key has 3 clicks first on for whatever it is second the dash comes on third the starter kicks in.
Before you put the key into the ignition Make sure that you Press the Break and the Throttle to the Floor ( max
Then turn the key on until The dash board come on and DONT START THE CAR
Wait 2 sec and keep the pedals Down to the floor
the service light under the management light should start flashing
it will flash 4 times leaving 2 second space representing each number
Zero gets 10 flashes
for exampleP0110
the light will flash ten times Break (2sec Or 1 not sure) then once, (2sec) once again, then ten
if you have more than one code it will stop for a break then gives the next code
its not a very useful way but helps when you dont want to go to the dealer for a lose socket
this is for Corsa C the Newer models have even better way to tell you the code i think which is on your Mileage Display It will show ECN0 XXXX
which is error code Number forget the zero and the last four digits is what you want
and this works for an astra Too
ive tested this on my own corsa and worked Very well
however if you don’t have any code stored it will start Flashing and keeps on flashing until you release the paddles