Hi. I have Ford Focus 1.6 auto. Was a problem with a gear box. First one was faulty, so changed to secon d hand one. Once I change it it stops shiftin gears and the car jumps then I shift to drive or reverse. Fault codes was shift solenoids and pressure solenoid open circuit. I changed another gear box, the same problem, just faulty code is pressure solenoid open circuit.Could you tell me where is a pressure solenoid based or could it be ECU fault?

was the oil clean of residue ?
you might have a faulty valve that makes the shifts rough

shift solenoid in transmission

Fuse box in glove box,fuse 39 20 amp,diagram in fuse box

if auto. trans then it's time to rebuild it.
if a 5 sp. time for a new clutch.

Sounds like you need to cover basics first. The battery cables are clean and tight? Are all the wires in the battery cable at the battery making a good connection? Sounds like a common problem and is in the service bullitins is that the ground wire attached to the battery cable end that goes to the body and then to the transmission case bolt has failed to provide a good ground and the acuators and servos and even the switches have'nt a good path to ground ( their is one but it's though other controllers and the power isn't strongly grounded. I f you were following a dianostic tree of good and bad the ground is the number one cause of your problem. Don't fix the old grounds just add new ones. and then clear codes and test it again. Oil leaks near the transmission to engine connection were found by me everytime that I was assigned to this set of problems. Ground corrected and the car was fixed.

SHIFT solenoid

Auto warning light comes on but goes off when car stopped and restarted. Temp also goes higher

try these websites www.autozone.com and www.alladtadiy.com if all fails stop by your local library and get your hands on a Haynes auto repair manual for your truck

• drain oil using allen key plug underneath gearbox till all oil is drained refit use new seal if old 1 is damaged then look at front of g/box quater of the way up is another allen key plug remove fill with new oil till it starts to run out hole refit plug and ur done

did you use the correct aditive to make the oil last and change some of its properties