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4l80e shift solenoid b stuck in off position code

I'm just not sure what to do about the dipstick fill tube. The OEM part is discontinued and there's so many available aftermarket parts online that seem like they will be a bad fit. Every description I've seen of someone installing something involves removing and rewelding a bracket and heating and bending the tube or is a stainless braided hose that doesn't seal tight, requires calibration, is hard to read and slow to fill with fluid.
The weather should be nice enough tomorrow that I can try to move the truck to a suitable spot to work on it without getting stuck in the mud. I probably should have kept it parked up there.
 
Do you do any welding or know a local shop that would do welding for you? if there is a local radiator repair shop near you, you might talk with them to see if they would weld the crack up for you. just pull it and take it to them. can't hurt anything more than it is now. pull it and clean it up good looking for a GM part number stamped on the tube or bracket somewhere. use that number to search online or post it for us to see if we can find something.

there is a website called oemcats dot com that is fairly good for searching GM numbers and giving you results where to find it along with giving you other vehicles it's used on to where you might be able to arm your self with knowledge for searching in some local pick-a-part junk yards.
 
Solenoid B stuck in off position.
I believe that this could mean that the solenoid will not actuate. I cannot remember how the TCM computer finds this information but I can lead you in the right ball park. If its an electrical problem chances are you can find the problem yourself. Its been a couple of years.
If the solenoid is stuck it could mean that it is not shifting the 2-3 shifting valve when the computer calls for the solenoid to be energized. So there are a few things that you can do. Remove the 2-3 shifting solenoid and inspect the o-ring for serviceability, that the check ball is not stuck and moving freely. You can also do a quick check and see if the solenoid clicks by using two nine volt batteries soldered in series with a positive lead and a negative lead. This makes 18 volts but don't worry it won't damage the solenoid. Trust me I have done it. You are listening for the click within the transmission pan when you touch the leads to the corresponding pins. Within the pass through connection are a series of pins. google 4L80-E passthrough connector schematics. Pins B and E. check for resistance and you can also check for the click using the voltage method that I mentioned. This should give you some idea about the health of the solenoid coil itself.
If the solenoid is working then drop the pan, remove the solenoid and inspect the O-ring, check ball and obstruction in the screen.
 
I did work on this a while back, sorry I haven't posted. I replaced shift solenoids A and B and the TCC solenoid as I'd had codes indicating all of those at some point. Also replaced the EPC solenoid because it had a broken out missing part of a screen. I replaced the internal harness with a Rostra brand replacement and the new one also leaks. Replaced the filter and pan gasket. At this point, it seems to drive fine when cold, going through all the gears on the way down into the valley, about 5 miles. After it's warmed up, it is just stuck in 2nd it seems. I have only seen the P0756 shift solenoid B code and P0161 O2 sensor codes since the repair and have only driven it twice I think. The people whose property I'm living on are telling me to replace the electronic control module at this point, but I'm more inclined to think the problem is deeper in the valve body.
 
even though you replaced them. do a ohm test on the solenoids when cold and again after it's warm and acting up. this is the issue I ran into with the EPC on mine. shifted fine when cold, but after warm it would shift hard. EPC ohmed out perfect when cold but ohm readings when warm were borderline within spec. replaced it with one from a working trans. seemed to do the trick. I also noted that the EPC that came out of mine did not have any markings what so ever where the one pulled from the known good trans had the GM part number stamping.
 
One other thing to note is what fluid you are using and what your climate temps are. these trans were built for dex 3 but GM wants us to use dex 6. dex 6 will thin out when warm more so that the old dex 3. I also like to use a bottle of Lucas trans fix in there when I service them. never had any issues with it and on some it seems to help them.

you can use it to thicken the trans fluid so long as when cold, the trans still shift's right away and not as if the pump is weak. when the pump begins to weaken, the first thing you notice is when cold shifting into reverse or drive takes a second to grab the gear. so as long as your not experiencing this, using the Lucas in the trans can be used.
 
NiceTruckOldMan said:
I just can't wrap my head around it running fine until it warms up, then faulting out. Does anyone know where is a good place to order an ECM from?
Click to expand...
IDK the cost, but I would think that you could pull one from a JY and take it to the dealer or someone who can re-flash it with your trucks vin and programming. GM might actually have an update that would fix the issue.
 
Sorry I haven't followed up in a while. I finally decided to get into the transmission again and took out the valve body just now to find an additional upper gasket for the separator plate above the check ballsas well as the one beneath. I hope someone can find humor in that, I just wish I'd taken it down last time I had it apart. I'll post again after I get it back together and test drive.
 
So I replaced the valve body, with the accumulator on top, but used my solenoids I had already replaced, because it had old solenoids. Also it came with a harness so I replaced that as the one I previously installed also leaked. I found the 6th bolt tightening the valve body in sequence was stripped :( Then I snapped off a bolt torquing the pan down, but it didn't seem to leak when I tested it out. It did better than it had been, clocking over 14 miles of finding all the gears. but then threw a code and got stuck in third coming back over the mountain pass. Also a delayed shift into reverse is noticeable most of the time and had some really sluggish starts. The code, as usual, is the P0756 shift solenoid b stuck off, but at this point, I'm thinking ECM all the way, because just driving it earlier after clearing codes and getting good results out on the road, I put it in 1st and 2nd on the dirt road and it threw the same code, with the shifter in 2nd! Solenoid b is supposed to be off when in 2nd, so what else could it be? It doesn't explain the reverse delay, I think that's from buying a super cheap valve body, but I think the sluggish starts may have been it starting in 2nd, which actually could be a problem with solenoid b stuck off. The weird thing is some scan tools are telling me there is a VIN error, like this ECM doesn't know what truck it's in, so I think that might be important. I had ordered one, but cancelled when I found a bunch of bad things about Flagship One, where I had ordered it from. So I'm researching where I might get one, the place suggested above didn't have any and they specialize in motors I don't have.
 
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