Re: 4l80e shifting ?
 

It's been this way for the last 3 months!....but I am a little worried.....checked all the tranny connections, could'nt find nothin...

Re: 4l80e shifting ?
 

Just because the transmission hasnt broke yet doesnt make it OK.

Do you own a Digital Volt/Ohm Meter?

Re: 4l80e shifting ?
 

yep...?

Re: 4l80e shifting ?
 

Did you "Ohm" the two ISS wires, Did you "Ohm" the ISS sesor?

Re: 4l80e shifting ?
 

no...it was too hot...what kinda reading should I be lookin for?

Re: 4l80e shifting ?
 

In Post #40 gave you the ohm reading for the sensor, I also provided PCM pin locations/wire colors for the ISS sensor. The ohm reading when checking continuity will be close to zero is the wire is good & in the correct location.

Re: 4l80e shifting ?
 

everything "looks" good...it's a brand new psi harness, all the pins are pushed in, connectors are tight...I should of switched the iss and oss connectors around and checked the codes.....

Re: 4l80e shifting ?
 

I think what cline's getting at is that he's given ya the info twice, and you still haven't gone out to the garage with the volt meter yet. :)

I'm breaking your balls, but it won't fix itself.

Re: 4l80e shifting ?
 

...only prob is, my "garage" is 50km away....

Re: 4l80e shifting ?
 

as an american, i assume that is a long distance? lol I'm kidding.
that kinda sucks tho....that would piss me off with the weather yall get up there.

Re: 4l80e shifting ?
 

lol...yeah, finally got a break from the 100+ degree weather we've been having...

Re: 4l80e shifting ?
 

100 degree weather???:waah:

Re: 4l80e shifting ?
 

yep....my igloo is melting as we speak....

Re: 4l80e shifting ?
 

pulled the wire off of the brake switch....now that codes gone.....?

Re: 4l80e shifting ?
 

did you have the switch wired correctly?

Re: 4l80e shifting ?
 

I wired it up the way as per cline's diagram.....brand new switch as well.....?

Re: 4l80e shifting ?
 

I think the hard shifts are gone now as well.....wtf?

Re: 4l80e shifting ?
 

my 4L85e seemed to shift hard its 1st miles...now seems to have calmed down a bit?

Re: 4l80e shifting ?
 

so I've f:censored:ed with this problem for quite awhile, got very upset and forgot about it....it's still shifting very hard. after 20-30 mins of driving is when it starts, I can stop and shut it off, then its good again for a little bit...tried checking the resistance in the wires, not getting anything although Im not sure wtf Im doing either!.....still throwing this code...I know this is the problem, but no clue on what to do...I would appreciate any input.:banghead:

Re: 4l80e shifting ?
 

Swap positions with the speed sensors, If the ISS sensor is bad, It will now effect the OSS signal to the ECM instead of the ISS signal.

Swap sensors.....Drive till it acts up....If the sensor is in fact Bad, It will not want to up-shift at all.....Stuck in 1st gear.

Re: 4l80e shifting ?
 

Great insight and trouble shooting techniques Cline! Now I know who to come to if I have problems when I fire up my new setup :lol:.
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Re: 4l80e shifting ?
 

I'll link this just because;


I can't stand this guys voice, but he is pretty good about "dummy" instructions on things like checking sensors and locating terminations. Its about the 717 on a saturn, but the concept of checking it is the same.

Re: 4l80e shifting ?
 

thanks.....I bought a new ISS....I'll see what happens.

Re: 4l80e shifting ?
 

well that didn't work....no reading on the wires either...

Re: 4l80e shifting ?
 

....I spoke with jon at psi, he gave me the pins for the iss, says he checked the tune himself, some thing is wrong in the tranny...any idea of what it could be??