2000 GMC Sierra 1500 won't shift into 3rd

[Brenden Burnham]

Not sure if this has any bearing but I just got out of a carwash and now the truck won't shift into third gear.  1st and 2nd and Reverse all work fine.  I checked the tranny fluid level and is good.  Just want to see if there is anything else I can check but most likely my worst fears have come to be.  Is the Tranny done?  What else to check?

[Brenden Burnham]

To add there is no check engine light.

[WeGone]

Had it happen on a 97 Silverado just over 100K miles, was the transmission.

Edited January 21 by WeGone

[Brenden Burnham]

6 minutes ago, WeGone said:

Had it happen on a 97 Silverado just over 100K miles, was the transmission.

When it does shift from 1st to 2nd it does not sound at all like it is slipping.  So does this typically mean it is the shift solenoid?  which would be the 3-4 one.

[WeGone]

1 hour ago, Brenden Burnham said:

When it does shift from 1st to 2nd it does not sound at all like it is slipping.  So does this typically mean it is the shift solenoid?  which would be the 3-4 one.

 Just getting on the interstate 1-2 no 3, Drove home in 2nd took it to the shop next day something inside let go had it replaced with a GM reman. Drove another 80K than sold it bought my 2000 GMC.

[Sharpz]

It could be a shift solenoid for sure.  Only way to find out is to either replace it or have it replaced.  There are plenty of Youtube videos for your truck that walk you through that process if you want to attempt to do it yourself. 

 

 

 

Edited January 21 by Sharpz
youtube video

[richard wysong]

a scan tool that does trans codes should show a bad solenoid. trans codes often do not turn on the CEL and trans codes may not show on your basic code reader. good chance its the solenoid or because it happened at the carwash wiring or ecm. a good scan tool is a neccessity to diagnose trans problems. you can watch LOTS of live data and get a good idea of what its doing

[Brenden Burnham]

17 hours ago, richard wysong said:

a scan tool that does trans codes should show a bad solenoid. trans codes often do not turn on the CEL and trans codes may not show on your basic code reader. good chance its the solenoid or because it happened at the carwash wiring or ecm. a good scan tool is a neccessity to diagnose trans problems. you can watch LOTS of live data and get a good idea of what its doing

Really has me thinking about the wiring.  I mean immediately after the wash it happened.  Not sure where the contact points for the wiring harness is but is it possible for them to get wet that are outside the transmission?

[richard wysong]

your first step should be to get it scanned. it will save much wasted time. the wiring goes from the pcm to the round plug on the drivers side of the trans. it could be as simple as the selector switch which is a common failure and is exposed to the elements on the side of the trans but you won't know without a capable scan tool

[dna9656]

I

d check the wire harness and it's plugs for damage, maybe water got in a plug. Richard seems pretty sharp with the scanner stuff, but before I paid a guy an hour's time to scan and trouble shoot I'd check that wiring stuff, you don't need a scanner to do that and there's no point in paying the scanner person to do it if you can IMHO.

[richard wysong]

good point, I don't think water alone would cause a problem unless the 

 connection was already compromised by corrosion etc. the selector switch is the most likely culprit to be affected by water alone. being in Nevada the truck probably hasn't seen lots of road salt or freezing temps so corrosion may not be an issue

[Brenden Burnham]

1 hour ago, richard wysong said:

your first step should be to get it scanned. it will save much wasted time. the wiring goes from the pcm to the round plug on the drivers side of the trans. it could be as simple as the selector switch which is a common failure and is exposed to the elements on the side of the trans but you won't know without a capable scan tool

Will a scan show something even without a CEL?  There is no CEL so does a transmission scanner still show issue?

[Brenden Burnham]

So an update.  I took it out this morning in case possibly it was something that had maybe got wet and dried off and possibly correcting the issue, I had this happen with getting a spark plug wire wet once threw engine code and misfire but ended up drying up and correcting itself(was on a dodge ram I had).  First two minutes of driving I was happy.  Felt normal it shifted to 2nd and then it actually shifted to third, I was like YESSSSS issue gone.  This was unlike yesterday where it would not shift to third at all.  However it never shifted to 4th so my the thought of the transmission actually being bad became more of a reality and not just a faulty wire or solenoid, or something electrical.

 

After it warmed up a bit(driving about 5 minutes), it got worse and I noticed it started slipping.  Would go to high rev's before sometimes shifting to second and same thing going to third.  In second it would sometimes go to 3k+ rpm's and backing up on the throttle would sometimes put it in third.  This was a hit and miss. Same thing going from 2nd to 3rd gear.  Sometimes it would go sometimes I would have to let up off the throttle and would eventually shift.

 

So in my mind the Tranny for sure needs a complete rebuild or replacement.  Something I cannot do on my own in garage.  Called one shop and want's $3200 for tranny rebuilt.  Wish I knew someone with a shop here that could lift and help me do the swap if that was the case I would probably take it on.  If not probably going to sell the truck to someone that has the capability to do so.  Just really sucks the motor and everything else seems great no issues drives really good(before tranny issue).  Second time I have had a tranny go out on one of these trucks.  Previous was a 1999 Silverado 1500 STL.  Just really frustrated at this point.  

Edited January 22 by Brenden Burnham

[richard wysong]

yes trans codes very often do not set the CEL, you may be right that it needs a rebuild but you may still want to have the trans shop scan it to make sure before condemning it. the electrical parts can cause many symptoms you wouldn't think possible

[Brenden Burnham]

1 minute ago, richard wysong said:

yes trans codes very often do not set the CEL, you may be right that it needs a rebuild but you may still want to have the trans shop scan it to make sure before condemning it. the electrical parts can cause many symptoms you wouldn't think possible

They want $130 just to diagnose it(am sure just a scan).  I could buy a scanner for that price but they obviously know what they are doing and what to look for.  They told me even if it was just the solenoids that it would cost most likely $2500-$3000 to fix and that who's to say that another issue may not come shortly down the road so a rebuild is highly recommended regardless.  Just really do not know what to do at this point.