Hello members,
I own a 2001 Chevy suburban LS 5.3 V8 and am at a loss, one day a month ago while driving at around 65 mph my burban dropped to what seems a lower gear. I was able to drive it to a nearby parking lot. Being that I'm in hell( Arizona) I figured maybe the transmission got hot. When I started it up after letting it cool down for an hour and put in reverse, it would not shift in reverse, yeah real fun pushing it backwards darn thing is a beast. I was able to drive home 15 miles away going 30 miles an hour yeah more fun. Since then I've pulled the pan, checked the A and B and TCC solenoid using the nine volt trick, all three clicked and checked continuity all beeped away. I put in New filter and fluid and put everything back together. Still seems in limp mode and still no reverse. All there is is park neutral and drive nothing else. I've used a scanner that reads transmission codes and the TCC solenoid showed up but I hadn't reinstalled that solenoid when I scanned it. After I out everything back together i rescanned and no codes popped up leaving to believe the wire harness is still good, maybe. I did have a no communication to EBCM and will say my brakes and emergency brake seem softer than before, could the EBCM be causing this enormous headache of mine? Thanks with any guidance. PS. I'm a YouTube amateur mechanic.

 

According to Repair Pal it might be a dirty or worn out TBI unit:

https://repairpal.com/stalling-or-lo...ottle-body-056