Dear Forum,

I won a 2009 Hummer h3 with a 4L60 Transmission. When I first bought the vehicle in 2012 she ran beautifully however the only thing that did not work was the 4X4 low and the 4X4 lock for the while time I owned it, now I never really go 4X4ing so it was not a big issue. So in late 2019 the initial problem when 1st gear started slipping a bit, to he point I could not drive up my driveway, however the good news is all of a sudden the 4X4 low and lock started working and so I could go up the drive way. I tried to research and the first thing told to me was my 1-2 solenoid needed replace. I dropped the pan and replaced all solenoids and the wiring harness also.Now at this point I learned my trans was a 4L60E but in all the videos I would see this thin looking plate called a Manifold pressure solenoid which my transmission does not have, not even a place to mount it at all. I thought this kind of odd as all the videos and diagrams I came across showed this solenoide but not mine....
After this did not work, I dropped my transmission and bought a rebuild kit. My friend and I took it apart all the way to the aluminum housing. Most of all the parts still looked brand new, I had ordered a few extra parts that the videos had told me are always good to replace. As it turned out I did replace the shell, and all clutch plates, and most of the O rings as required. Everything else looked brand new! so we put it all back together and re instaled it back up into position under the truck.

At first she would not move at all, you could shift into any gear and nothing happened, then I cleaned the TCM computer, and boom we had 1st gear and reverse in all 4X4 salections. But would not shift out of 1st....in fact I ended up having to take it from where the shop was to my house like 4 miles away in 1st only doing like less then 25mph all the way. (how embarrassing, for sure) I reid my diagnostic on the truck, and then it appears I might have a bad TCM computer, So I ordered another one preprogrammed with my Vin#, it came in today, I installed it and still the exact same....i'm having no luck here,

My codes before I bought the mew TCM unit were; P2764-00 TCC Pressure control solenoid circuit low voltage / P2769 torque converter clutch circuit low

I would greatly appreciate any assistance on this, it is driving me crazy.....and has become super costly as well. PLEASE HELP!!!

 

Welcome to HF.

You might have learned something, maybe. There is only one thing on modern vehicles I will not try to repair, and that is auto transmissions.

It doesn't matter what the innards look like, you say "brand new". You have to understand that ATs die from heat and/or fluid contamination. When they assemble new transmissions, every internal part goes through a transmission parts cleaning machine that has to remove oil, dust, metal shaving specs, fingerprints, down to a standard of like 0.02MM squared (pretty freekin small). The machines cost over $75K to do the parts cleaning and have filters to replace once per week. So when you take it a part, look at all the pieces in your grubby hands, then set them on a bench, ground, floor etc... before you put them back in, not going to be long before the second failure.

A reputable transmission shop removes the trans from the vehicle, removes the innards, cleans the case with a trans parts cleaning machine, cleans the valve bodies if salvageable in said machine, then uses all new parts in a controlled environment. Trying to cobble together an effective repair on you own based upon internet this and that is a long shot unless you are dealing with one simple failure.

Find a reputable local transmission specialist and let them fix your problem. I highly doubt anybody here is going to be able to walk you through a trouble shoot after you and your buddy did who knows what when you had it apart after your initial codes.

Good luck!

 

Hey Doc, isn't that what they call an 'oxymoron'?

 

Start by checking #26 & #34 fuses to be sure good. If so, then disconnect the transmission 20 pin connector and measure the resistance of the Torque Converter Clutch solenoid across pins E and T. It should read 21-33 ohms. If not, then there is an open in the TCC solenoid or a wiring issue going to or coming from the TCC solenoid. If so, check for shorts/opens/high resistance in the wiring.

 

They are like doctors, Indian chiefs and candlestick makers, some are excellent, others .............. not so much.

I use a guy that I know socially, one of my best friend's cousin. The shop is run by Fred Sr. and Fred Jr.. Sr. has worked on transmissions for 40+ years. Clean modern shop. Doesn't hurt that I helped him buy his building some years back. Midway Transmission in Roseville. Great place for Gratiot Cruise night!

While I am not in a hurry for AT failure, I know when it happens it is time for some fun picking out the best bullet proof parts for an super HD reliable rebuild on anything I have.

I would urge that everyone driving older vehicles out of warranty get to know a transmission guy and a motor building guy, then take care of them so they take care of you.

 

https://twincharlotte.com/30-common-...-charlotte-nc/

 

Thank you so much for this HummerZ, I will try this as soon as I get a good wiring diagram for that section. I live in Saipan, CNMI, its a small island in the pacific inbetween the philippines and Hawaii, north of Australia, so I do not have a lot of mechanical opportunities here to take to a professional, lol I try my best to make due with what I have here on island. The issue does seem like an electrical one and not mechanical....I just didn't know what else would control the pressure control solenoid other then the TCM unit (small unit above the ECM unit right side of firewall next to the windshield wiper fluid). I know I can but a rebuilt transmission but thats a lot of money and if it does the same thing again.....I would be really upset, so I figure I try everything else possible first then that as a last resort. I really appreciate the answers for this one, If I am able to find a solution I will post it as well.

Sincerely,

Mike

 

Thank you also so much Bronxtech, I really appreciated the article. 1 was really close to my issue but just not quite their. Was a great article though and I think will help a lot of others who find this post, out along the way. Thank you again,

Sincerely,

Mike

 

Dear doc Olds, thank you so much good sir, If I lived in the states this would be a great opportunity for me, but I live out in the middle of the pacific ocean, lol So I am stuck to what I can do here. I love my truck and she still looks new but I have sing like $7K into here over the last year, and its getting quite expensive according to my wife, lol you know how that goes, they just want it to work. Thank you again good sir,

Sincerely,

Mike Dilley