09 western star with a Detroit series 60 lazy tach.

I have a 09 western star with a Detroit series 60 in it. I started noticing the tach being a little lazy lol it just wasn't working right after some research and talking to western star service I had 2 opinions one said rx module the other said speedo. So I changed the rx module there was a tiny bit of corrosion on 2 pins I cleaned them up I put dialectic grease on it and installed. I noticed immediately dash lights weren't right it also threw a code 35 oil pressure voltage high I removed and totally cleaned off grease plugged back in dash lights seem to work fine now it is still showing that code btw now the data star is not relaying any info. Will the speedo throw all this out. Plus what does the ecc due I replaced that a year ago for another issue.

 

Yes 4900ex the data star was working before I put the new rx module on also for some reason I now have a code showing up code 35 since the new rx module .. I'm going to switch back to old one to see what happens with the data star . It all started the other day I noticed the tach just wasn't right it wasn't responsive lazy if you will, then several hrs later I shut it off start it up np gauges work it's like wtf after a minute they slowly all start working but some not accurate that's even I noticed the data star still working one western star service guy said rx module the other one said speedo I did the rx module you know the rest. What's the data bus? Is that a part I may need to change. Btw the gauges seem to be all working properly other than the data star. Thank you any help is greatly appreciated.

 

One more question will a code keep showing on the display till I get to a place to get it cleared or if I do my own diagnostic will it get off the dash and stay in memory..