Updtae,
I have replaced the TCM and the gearbox faulty message is gone, but things still the same.

 

I'd get a Diagbox or Planet diagnostic.

Your generic reader may be failing to fully see all fault codes

How to: Find and get a Planet / Diagbox Diagnostic

If you've signed up to this forum for help with your Peugeot (don't worry, most people do!), then you'll probably be recommended to get a "Peugeot Planet" diagnostic before proceeding. The reason for this is because some faults could be caused a number of different things - the "anti pollution...

www.peugeotforums.com

 

ok so i got the peugeot diagbox (thank you by the way @Gibbo for giving the guide) and i have found so many errors that i cant even write them, i uploaded 9 pictures of all the errors here:


as i noticed there are some errors that are not right, for example it says side lamp error but all lamps are working good, there are more errors like that.. why is that?
I showed you every error. if you think there is something that is not important for now, you can ignure it for now.
i only want to fix the gearbox and abs problem as i cant drive the car properly...

 

Those codes could all be historic codes, from a previously flat battery, etc. What you should do is erase all the codes and see what comes back.
And have you looked at the transmission multifunction range selector switch? It sits on top of the transmission and has contacts inside it and relays the position of the selected gears to the ecu and to the dashboard display. If the contacts are worn or the switch is out of adjustment, transmission fault codes are triggered, the dash display gives funny readings and the transmission stays locked in one gear, usually third and won't change down

 

That is exactly what happens but only it gets stuck at 2nd gear, didn't check that thing i for sure will try that.
About the other codes, i tried to delete them, they always come back after a short drive or immediately...

 

This is the procedure for adjusting the mulifunction selector switch
http://www.peugeot206cc.co.uk/repair-206/206/info/gb/b2cg79k3.htm

Just looking at your codes, you have one for a permanent brake stop switch. This will disactivate the cruise control and give you the fault code for that, but moreover, will give you transmission problems and codes to match. This is because the stop switch on your pedal is an input to the computer which determines its gearing according to acceleration, braking, etc. No switch input equals confusion so a check engine light and limp home mode may develop

 

Thank you thats really helpful i will even try that with the current selector switch becauae the mechanic that replaced the gear didn't do it like that.
About the brake stop switch it has been replaced twice, nothing changed.. actually i dont have any check engine light on the cluster but only abs/esp error light, gear box faulty after a long drive, and side lamp error (even though all lamps works).

 

Might need a wiring diagram next, to see what all these systems have in common. And all the ground wires were put back in place after the transmission was replaced?

 

Yes, as long as i saw every cable was been placed as it was before.

 

The brake pedal switch has two sets of contacts - one for brake lights and one for input to the computer. To test , disconnect the switch connector with ignition on, there should be 12v coming in on pin 2. Reconnect, then test the voltage coming out of the switch with pedal depressed on pin 1, if switch is good, this should be 12v also. The pin 1 wire goes to pin 17 on the ESP control unit so testing that with the brake pedal depressed should give you 12v also, to rule out wiring issues in that circuit

 

Hi Is there issue with the water system Is there always losses of water in the cooling system