Auto Trans pressure switch ?

[midlevel]

My VS series 2 V6 Calais has done 79,000 K since new and its a great car. Recently, the Check Power Train fault light remains ON. 1 year ago it illuminated so I replaced the o2 sensor. I decided a few days ago to conduct the 80k service and try to fix this fault. My mechanic told me the Auto Transmission Pressure Switch needs replacing cost $433.00. Mechanic also told me after the replacement part is installed if the Check Power Train fault light still remains ON, the ECU is faulty and it will also need replacement @ cost $600+. The car runs perfectly and changes gears correctly so I feel this expensive assumption could be a waste of money and I'm worried about driving the car at the moment. Is there a simple fix ?

[delcowizzid]

firstly check the error codes using a paper clip theres a thread on here checking error code VR-VS search for that and check the codes and see which ones you get then reset the ecu and see if the codes come up again then report back what codes you have

[midlevel]

Mechanic did service on auto @ 80K changed the switch and filter, dash warning gone & back to normal

[GLITRES]

a bit of money to spend?

[wayno3971]

i hav a code 28 and i had oil come out a hose that comes from on top of the gearbox and goes into the chassie what caused this if anyone knows

[Paul13pp]

i hav a code 28 and i had oil come out a hose that comes from on top of the gearbox and goes into the chassie what caused this if anyone knows

The list fault for code 28 says "pressure switch assembly short circuit - auto transmission code"