what is fault code.po118,and code po234,please explain ,thx.

 

P0118 is for a detected fault in the ECT circuit (engine coolant temp). Most likely cause is the ECT sensor itself before a wiring issue.
P0234 is for a detected overboost condition. Common cause of that code is the turbo actuator motor becoming seized (vacuum motor on the turbo). It's available as a separate part now vs "serviced only in turbo assy".

Of course, PROPER diagnosis needs to be done before replacing any parts. I only mentioned the most common cause of each fault code for reference. Well OK the ECT code, I'd just replace the sensor and see what happens. They're less than $25. Make sure to pick up a new o-ring seal and plastic clip for it at the same time, if not included with the sensor.