Hello.
i got a 00 Silverado with a 4l80e swap from a 07 suburban. Truck drove shifted and all great. Came back from vacation. Truck would hold first gear til like 3500-4k rpms then shift to 2nd and then 3rd immediately. Would go into 4th normal but then shift back and forth then hold 4th fine. Down shift try to get to 2nd truck would rev up then finally grab. No slippping or anthing. I can command all gears with HPTUNERS and it’ll hold the gears no issue. I command the solenoid A and a won’t click or anything. Tested ohms and 9v battery trick and both worked. But can’t command it to do anything. Obviously replaced all solenoid and harness. No change. Not sure if there is something else that would cause solenoid a to stay on with the key at all times? It get hot just sitting with the key on. Not running

im open to any suggestions and hoping someone has some insight. I can command solenoid b and get it to click but nothing from an and HPTUNERS shows it’s on when the truck key is on. But I can’t command it off either. It says it’s off but no click either way.
2000 Silverado og 2 wed 4l60e swapped to 4l80e 4wd. Segment swap done correct. Everything ran and drove and shift great. Truck sat for a week and then this issue. Considering swapping ignition harness but I assume I would have other issues also.


thank you in advance

 

You can try checking the resistance of that solenoid at the big round case connector. Look up a wiring diagram to see the pin out.

I think the resistance for the various solenoids are 5, 10, and 20 K ohms, the shift solenoids being 20, IIRC.

Maybe you have a short on your wiring harness?

Did you repin the big case connector? Or did you use one of those adapters? Some of those adapters have had issues. But it's strange that everything worked well before? 🤔🤷

 

appreciate the reply. I have checked the ohms of solenoid A and it was correct. I had. A issue figuring out how to check the external harness side. I did use a ICT HARNESS and tried connecting just the oem harness since they both have the same plug location to the solenoid as far as I can tell. Still nothing solenoid A still turned on and won’t turn off. HP tuners says it’s off when I command it but it won’t click either way. I traced the wires as best as I could. Not to sure which ground to check for the solenoids since I do know they ground out and that could be my issue causing it to stay on. I’m hoping someone can chime on the location. My brain is fried and I’m hoping to get something mentioned im missing.
pulled the pan 3 times and can’t keep paying for fluid haha
I did also try a new internal harness with no change.

 

**** that truck looks ****

 

Sounds like RODENT DAMAGE.
Possibly a Rat chewed insulation off Solenoid A ground wire.
UNPLUG transmission, and report back.
Should get ya 2nd gear with NO electrical connection to trans.

 

so from my understanding the pcm controls when to ground the wire and there isn’t a direct ground. I’ve inspected the wires pretty much top to bottom. I’m leaning towards a bad pcm. I can control solenoid B but nothing else in the trans. Solenoid a is clicking as soon as the key is turned on. But I can’t get it to do nothing with hp tuners.