anyone know anything about 4l80e gm overdrive trans.....its in my 91 chevy 1 ton van....takes off in 2nd gear....was throwing code 86-low ratio error solenoid b...changed both solenoids ...now it throws code 81-shift solenoid b circuit error.....still takes off in 2nd...bangs into reverse. have been told it could be in trans or could be in van electrical....?????help i need it to tow buggy to the woods!

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Hey,can you hand me those zip ties and that roll of duct tape?!

My truck was doing about the same thing and it was a blown fuse to the ECM.

have you changed the trans or ecm lately?

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If it ain't broke ill fix that

changed ecm about 2 years ago....other than that speed input and output sensors on tranny about a year ago

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Hey,can you hand me those zip ties and that roll of duct tape?!

ignition switch

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i dont always ride my buggy but when i do im glad it has a bad ass bow tie makin the horsepower

Jesus loves me, but everyone else thinks im an asshole.

Our Lady of Blessed Acceleration, don't fail us now!

I agree just cause purp said so

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If your clutch ain't slippin,, you probably got it adjusted right!!!!!

all fuses r good...all connections connected....put in new ignition switch this morning and still no luck

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Hey,can you hand me those zip ties and that roll of duct tape?!

someone? anyone? 632 views and only 3 or 4 suggestions?

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Hey,can you hand me those zip ties and that roll of duct tape?!

try this:
1. First, insert the ignition key and turn the ignition switch to the “On” position (Do not start the engine). Leave the switch on for 11 minutes. The security light may flash or be on steady during this 11 minute period. Make sure the light is no longer on or flashing before proceeding to #2 .
2. Turn the ignition switch off for 30 seconds.
3. Turn the ignition switch to the “On” position (as in step #1) for 11 minutes again.
4. Turn the ignition switch off for another 30 seconds.
5. Turn the ignition switch to the “On” position for 11 minutes a third time.
6. Turn the ignition switch off for 30 seconds one final time.
7. Turn the ignition switch to the “On” position one final time and wait 30 seconds.
8. Attempt to start the engine. If the engine starts and runs normally, the relearn is complete. If the engine does not start, check for trouble codes and address them before attempting the relearn procedure again.

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If your clutch ain't slippin,, you probably got it adjusted right!!!!!

I know this is not an answer, but a friend of mine specialize in gm transmissions its all he does.. His name is tony #317-501-1680 give him a call great guy and loves to talk

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Air cooled forever,i hate rusty tools!!!!!!!

If I could help you I would in a second. I'm as smart as a bag of hammers when it comes to this kind of stuff, sorry.

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Of all the things I've lost, I miss my mind the most.
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I'm not sure if this will help my truck said the same type of thing yours does and it ended up being the park neutral position sensor. it acted the same way as yours

mine is a 91...will this work on it or is it for obd 2(later model diagnostics)

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Hey,can you hand me those zip ties and that roll of duct tape?!

I don't know,,just a shot in the dark,,,probably obd2

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If your clutch ain't slippin,, you probably got it adjusted right!!!!!

the early 4L80s had lots of issues with the wiring harness for the trans internal and external if you have a small bolt that goes throught the center of your plug in the harness for your trans then it is early and needs updated I am an ase cert. trans builder at the same shop for 15 years....I can get you the parts if needed or do total rebuild... the wiring kit comes with a new updated internal harness and a new plug and pigtail for the outside that has to be cut and connected

ran the trouble codes again after ign switch and now its back to 86 low ratio error (solenoid b closed) have to go to lima tommarow but if i have time i will check plug....its a 91 isnt that 1rst year?

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Hey,can you hand me those zip ties and that roll of duct tape?!

i can unplug it and it still starts ? should it?

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Hey,can you hand me those zip ties and that roll of duct tape?!

yep 91 was the first year,what did you unplug the trans plug or the MLPS( manual lever position sensor)

nuetral position swich....

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Hey,can you hand me those zip ties and that roll of duct tape?!

no the engine should not even crank with the manual lever position sensor (mlps) unplugged, sounds like you got a wiring gremlin

thats why i was leary of just throwin another trans in...dont want to go through that if its simple as replacing harness or elec prob with van that could be easy fix

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Hey,can you hand me those zip ties and that roll of duct tape?!

yes you definately have a wiring problem the van should not start with the switch unpluged. check to make sure you didnt pinch the harness when you installed the tranny. check ecm connecters for corrosion or water intrusion. if you dont find anything I would suspect the ecm? when you clear the codes do they come right back? or do you have to drive it for them to reapear? sounds like the ecm is in "limp in" mode because it dont know what gear you have selected?

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If it ain't broke ill fix that

it is the original trans...just started trippin last week....if i clear codes it takes a while to come back...ecm new a couple years ago

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Hey,can you hand me those zip ties and that roll of duct tape?!

Oh sorry I thought you said you changed the in an earlier post but I see I read it wrong. Does it start in second after you clear the codes or only after the code sets? Does third and overdrive work? Torque converter clutch work?

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If it ain't broke ill fix that

yes it always starts in second...if you manually put it in L1 it feels like the brake is on and trans struggles to move truck...shift it into any other gear and it will go but it takes off in second....will down shift from od to D and torque conv seems to be doin its thing okay....also when you put it in reverse it engages very hard

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Hey,can you hand me those zip ties and that roll of duct tape?!