So of course finished the major and upon first start up and drive my sdl came on flashing. Next drive it started flashing immediately after starting so i knew it was bad components. Third drive it came on solid and shut down a bank so I pulled over and shot the exhaust and it was the rhs bank 1. So I unplugged the exhaust thermocouple on that side or whatever we all want to,call it and the sdl immediately upon restart was flashing again. Drove home and installed the new spare thermocouple I have and went for another longer drive and end of problem, So Far. Because you never really know if these black boxes are fixed. I have allways had a temp gun(rc model for glow engines) in the car because they are small. Now I just have to fix the small coolant leak. (Knew i should have tighten hose clamps more)
I have an sdl on cold start some times. Its agrivating especially when I have gutted cats. No CELs but the sdl pops up sometimes.
I always remind folks after majors to make sure they have the right side cat TC/SDECU plugged into the correct port on the harness and not swapped with the bypass valve TC/SDECU The connectors on the harness are colored. Look at the left side. The cat port is the same color and the other one is the bypas valve. Just something to verify. It’s been swapped often and by quality shops.
Yes Mine are marked with colored zip ties, blue to blue Red to red Green to green I did not realize that a slid light could be changed to flashing by just unplugging thermocouple until I read all your stuff Plus once a bank is cut on the 5.2 a heat gun told m right away which sde. Needed to look at. And a quick unplug got me home with a flashing light. Not sure if ts you Bob but I just ordered two thermocouples because I used my spare.
This exact thing happened to me earlier in the summer- was driving me crazy especially after an otherwise flawless major. Another thing that took some time to figure out was a flashing SDL on startup from a previously faulty cat ECU connection can be removed with an OBD2 code clear. Not sure how they are connected but it worked.
Bob was very helpful diagnosing my SDL when I first bought my car. After swapping stuff around and replacing some components it turned out to be swapped wires on the by pass TC. Major was done right before I bought my car. I like the idea of marking the connectors with zip ties!
My Majors are never flawless I allways have small issues. That being said I did a lot of extra things this time so I introduced some issues where there would not have been on a reduced item major.
