Transmission not shifting into 2nd or 4th

jsprewell

Well-Known Member
Back at the beginning of December (2014) I was having various issues and codes for the fan clutch. Also, the Envoy was spitting out a P0757 code. My scanner said it was a "Shift Solenoid B Stuck On" error. Right before this happened I was having the classic semi truck sound coming from the fan. I was living with this for a while. Then the codes for the fan clutch showed up. Then the next day when I was returning home from class, I was stopped at a red light. When I started going, the loud noise from the fan started (no biggie), then all the sudden, it wouldn't shift into 2nd gear, and the Check Engine light came on. I pulled over to the side of the road for about 15min thinking I could nurse it home. When I started it back up, it ran just fine and I got home. For the next few days I left it sitting at home. Then I turned it back on, no Check Engine light. Thought what had happened was a fluke so I drove it to work the next day, again, drove fine. On my way back home, it wouldn't shift into 2nd gear again about halfway home (live about 15miles from work). Again, pulled over to the side and waited 15min. Turned it back on and drove it home no problems. Called our mechanic and he said he could look at it in about a week. A week later, drove it to the mechanic, leaving the Check Engine light and codes uncleared so he could look. No problems driving it to the mechanic. He got back to me and said he replaced the fan clutch and couldn't replicate the no shifting into 2nd gear problem.

The Envoy ran just fine until a few days ago. Wouldn't shift into second on my way back home from work again. This time my sister's husband told me to try and "force" it into second by throwing it into Neutral, then back into Drive. This worked. It also was able to shift into 3rd with no problems. BUT, when it gets to about 45mph, it won't shift into 4th. It seems to go into neutral. I can put into the (3) shift position and drive it at about 45mph without it going into neutral, but the RPM's are around 3,000. No codes, no nothing. So I let it sit at home for two days. I looked at the fluid, it's a light brown and probably needs changing. Yesterday I took it out for a test drive, about 10 miles into my 20 mile test, it started messing up again. Same issues, this time it threw the Check Engine Light and codes. First code is P0741 (Torque Converter Clutch Solenoid Circuit Performance Or Stuck Off) and the second one is P0757 (Shift Solenoid B Stuck On).

For now, I'm going to just let the Envoy sit and take it to a transmission shop near where I live early next week when I have time. I did a little research and found similar issues but nothing like what I was experiencing. Any thoughts about the problems so I'm not completely stumped when I take it to the shop?
 

Texan

Well-Known Member
What is the maintenance history? Trans filter and oil change lately? How many miles?
 

AtlWrk

Well-Known Member
A few thoughts:

When you say it won't shift into second do you mean it just hangs in first indefinitely regardless of speed/throttle? Or that it feels like it's going to neutral instead of second?

What happens when you manually shift into 2nd and start there?

Solenoid B is ON for 1st and 2nd, OFF for 3rd and 4th. If it was stuck on as the P0757 says you would expect to lose 3rd and 4th, with 1st and 2nd unaffected. There is a possibility that it's not the solenoid itself (e.g. 2002 PCMs don't have the DTCs for electrical connection issues) but it is fairly easy to replace the solenoid once you have the pan off (which would allow you to change the filter too). I doubt this will fix all of your symptoms but eliminating one problem would make diagnosing the rest much easier.

No 2nd and no 4th makes me think there's a problem with the 2-4 band or its application circuit. These bands do fry (heavy towing in 4th). Another somewhat common issue is checkballs slamming there way through the separator plate resulting in all sorts of unpredictable behavior. It's a fairly cheap fix parts-wise (new plate, torlon balls, and gaskets) but it does requires dropping the valve body (messy!).
 
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jsprewell

Well-Known Member
Is there an easy way to tell which gear it's in? Because in all honestly, with this problems, I guess I couldn't tell. I know that it starts fine, when I drive it usually shifts rather quickly (most of the time it feels like a rather hard shift) into second. With the latest issues, it acts like it wants to go up into 2nd, revs go up a little, then acts like it drops into natural. (maybe it's when I let go of the gas and try to go again that it drops into neutral)

Anyway, I've put it into the (3) and nursed it home. While in that spot, I can feel 1 shift and then around 40, it doesn't shift and the rpms climb. If I move it into (D), during this time, it drops into neutral.

Hope this helps a little.
 

Dan_G

Well-Known Member
I would buy and install this kit along with a new filter and dex 6 fluid ....
So you are recommending that the OP, drop the tranny, disassemble the thing and install that rebuild kit from eBay and re-install? Is this something that a backyard mechanic can reasonably do ? Don't get me wrong - I love the idea of being able to service an automatic transmission and fix this kind of problem. It just seems kinda complicated for someone that has no experience. Does that ATSG BLUE 4L60E TECH MANUAL included in the eBay rebuild kit have enough detail for a lay person to pull this off ?
 

swede

Well-Known Member
Same here, there are TSB's with Information about this issue.
 
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jsprewell

Well-Known Member
It's got about 170,000. I had it flushed and fluid/filter replace about 110,000. Other than that, nothing. Although I did have a replacement engine put in about 10,000 miles ago. Don't think anything was done to the transmission at the time.
 

AtlWrk

Well-Known Member
The kit linked to does not require dropping and disassembling the entire tranny--just the valve body. I have done this in the driveway. There is nothing intrinsically difficult about the installation other than following a lot of directions to the letter and staying very very organized. Frankly, it wouldn't be hard to screw something up or get lost so it's definitely not for everyone. If you want to go this route you can call around as some shops are willing to install a kit like this for you.

I really don't know why they bothered including the ASTG (though it's definitely a nice-to-have). It's wayyyyy more information than anyone needs unless they're doing a full rebuild--which is not what we're talking about here.

Though I just now picked up on the fact that you had it flushed...by whom? dealer or trans shop? I'd be concerned now that your valve body has been contaminated.

I still stand by dropping the pan, putting in a new filter and fluid, and a new solenoid ($15-25) and going from there...
 

marinegrunt

Well-Known Member
I'm with AtlWrk. If it's throwing the shift solenoid code there's a good chance it needs replaced. It's possible it's something else causing it to throw that code. I'm not one to throw parts at a problem but I would in this case. I think it's worth a shot considering what it would cost to have a tranny shop diagnose it. I believe those solenoids are only $20 or so.

I don't think a bad solenoid would cause it to go into neutral. There may be more going on inside than just a solenoid.

Those solenoids are a piece of cake to change out. If I remember right there's a little clip that holds it in and you just plug in a little harness. Awhile back I posted some 4l60e manuals. The service manual has a troubleshooting section. It also explains how it functions. It might be worth looking through.

http://gmtnation.com/forums/topic/12708-4l60e-manuals/
 

Dan_G

Well-Known Member
I found this guy on YouTube - Transmission Bench. He has a complete video series on 4L60E teardown and re-assembly. He's obviously an instructor since the videos are just unbelievably good. Each video is broken down into a specific section of the unit, they are very detailed. A lot of knowledge and high quality production work went into these videos. It looks to me like they were from a course on transmission repair. If I ever have trouble with the transmission I'll just use these videos and give the rebuild a shot.

https://www.youtube.com/watch?v=dhkP49tBQaM
 
I have a very similar issues (see transmission issues about 5 threads down). I have changed the solenoid that was indicated on the computer, flushed, filter, new fluid and even threw in some Lucas. I am at wits end...the transmission was working fine, replaced the engine and have had nothing but problems every since. The vehicle did sit for a while before the engine swap. I have also checked all the grounds as well. If i can't fix it relatively soon there will be a cheap envoy for sale!
 

Mark20

Well-Known Member
Dan_G said:
I found this guy on YouTube - Transmission Bench. He has a complete video series on 4L60E teardown and re-assembly. He's obviously an instructor since the videos are just unbelievably good. Each video is broken down into a specific section of the unit, they are very detailed. A lot of knowledge and high quality production work went into these videos. It looks to me like they were from a course on transmission repair. If I ever have trouble with the transmission I'll just use these videos and give the rebuild a shot.

https://www.youtube.com/watch?v=dhkP49tBQaM
Not to hijack the thread but that looks exactly like what I need to understand tranny's.
 
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jsprewell

Well-Known Member
Okay guys, I thought I should post an update.

I decided not to take it into the transmission shop and decided to replace the shift solenoids with the help of my sister's husband whom is a mechanic. This looked easy enough and with his help we were able to do it in an afternoon. The shifting 1-2 is fine, but the 3rd/4th no shifting is still there; it just goes into neutral. So, now knowing it needed more work, I took it to a transmission shop nearby. He called back earlier today and said that it would need to be rebuilt in order to fix the problem. So I just gave the go-ahead and he said it should be ready by Friday. At most it will be $1,650.
 

mntegra01

Well-Known Member
FYI, trans will not shift to 4th if the trans temp is too high cause by slipping clutches and friction.
 

Sparky

Moderator
Um, this thread is 3 years old now.
 

Matt

Silver Supporter
mntegra seems to be necrothreading a bit.
 

mntegra01

Well-Known Member
mntegra seems to be necrothreading a bit.
Sorry guys, I didn't notice the date when using my phone, I thought it was a month ago. I was actually hitting threads that popped up on the bottom of the mobile site, I guess its just recommending anything for me. Sadly most of these vehicles are pretty old now and just about every situation has been encountered and fixed by now. I'm just here to help and give help if I can.
 

Sparky

Moderator
Mobile site might leave out info like that, I haven't actually checked that recently. Good point. I'll look!
 

Mooseman

Moderator
Yep, we realize that. If you hit the "new posts", it should just bring up the most recent ones. And after going through the threads I'm interested in, I hit the "mark forums read". Gets rid of the clutter.
 

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