4l60e 4th gear problem
Thread Starter
Teching In
Joined: Nov 2014
Posts: 26
Likes: 1
4l60e 4th gear problem Ok so problem is 4th gear works sometimes, but will randomly shift down into 3rd and not shift back into 4th. Trans is of unknown year and mileage but is behind my 5.3l. If I command 4th with hp tuners it shifts with no problems but when I unhook the laptop it will shift back into 3rd. I'm quite a long ways from home and I hope I make it back lol. Does anybody have an idea what's wrong?
Thanks
Jeremy
Thanks
Jeremy
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
Did you scan for codes with HP Tuners?
The fact that you can command 4th gear indicates the trans is fine.
Setup the HP Tuners scanner to show you Trans commanded gear and temperature while you drive and monitor it.
I suspect that you will see that the PCM is commanding 3rd gear when it unexpectedly downshifts. This is then likely due to an engine sensor issue or high temperatures.
The fact that you can command 4th gear indicates the trans is fine.
Setup the HP Tuners scanner to show you Trans commanded gear and temperature while you drive and monitor it.
I suspect that you will see that the PCM is commanding 3rd gear when it unexpectedly downshifts. This is then likely due to an engine sensor issue or high temperatures.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
The value "Trans -> Current gear" in the HPT Scanner is the commanded gear.
There is little reason to think the "actual" gear is anything else unless there is a serious problem in the trans.
http://www.hptuners.com/forum/showth...s-Current-Gear
There is little reason to think the "actual" gear is anything else unless there is a serious problem in the trans.
http://www.hptuners.com/forum/showth...s-Current-Gear
Thread Starter
Teching In
Joined: Nov 2014
Posts: 26
Likes: 1
The value "Trans -> Current gear" in the HPT Scanner is the commanded gear.
There is little reason to think the "actual" gear is anything else unless there is a serious problem in the trans.
http://www.hptuners.com/forum/showth...s-Current-Gear
There is little reason to think the "actual" gear is anything else unless there is a serious problem in the trans.
http://www.hptuners.com/forum/showth...s-Current-Gear
Ok so problem is 4th gear works sometimes, but will randomly shift down into 3rd and not shift back into 4th.
,,,
try light throttle until 4th
Thread Starter
Teching In
Joined: Nov 2014
Posts: 26
Likes: 1
It doesn't seem to matter what throttle position I'm at when this happens. Also the pcm is saying go to 3rd gear. I just don't know why that's happening.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
If the PCM commanded the downshift to 3rd and the trans downshifted, then the trans is OK.
Why not try logging every time you drive - if you can post a log that includes the unexpected downshift, we might be able to help you figure it out. Yes, you can post log files here.
Why not try logging every time you drive - if you can post a log that includes the unexpected downshift, we might be able to help you figure it out. Yes, you can post log files here.