Hello everyone,
New member seeking some assistance. Having tranny issues and I can't find anymore solutions or any tips and tricks I haven't tried.
I've been referencing these forums for all my issues and I have exhausted all my options

2007 Monte Carlo SS - 5.3L - Bone Stock - no mods at all
- Transmission started acting up with all the normal issues. So I replaced 4th gear clutch/hub, new frictions, new plates.
- Replaced every single electrical component related to the transmission, pressure sensor, all solenoids etc.
- New cv and suspension parts
- 13 qts of AC Delco Dexron 6

The day I started driving it again the key fob died at SOS office. So I just don't lock it for now. Regrounded the BCM in the a-pillar, no change.

I got a couple hundred miles out of it, then lost 4th gear, then I was in limp mode. No check engine light.

Pulled the positive cable and held the key to set the relearn. Got 60 miles with 4th gear and smooth shifting all the way up and down. At the end of the 60 mile cruising I got the dash display TRANSMISSION TOO HOT, IDLE ENGINE. First time in 4 years. After cooling, back into limp mode.

Installed an extra cooler.

Hooked it up to a scanner, cleared fault codes, reset TAPS, but it will not go into relearn again. I've checked the fuses, nothing blown. I am currently chasing wires to look for damage or possibly loose grounds.

Where do I go from here? New TCM, or a hand grenade and insurance check?

Any help would be appreciated.

Also, in this particular model, does anyone else seem to think that it feels hot in the engine compartment? My gauge has never gone over halfway but the engine always feels much hotter than it should.

Thanks in advance, and thanks for all the previous info that helped me thus far!

 

Welcome to the forum, I am not certain if this is the culprit but it could be in need of a new bcm and reprogramming from a dealer? There are people on the forum with more knowledge on this than me, but it sounds like it could be the culprit, I believe if it is the bcm you can buy a used one from a wrecker and then have it programmed to your car as it seems like all the issues are computer related

 

I don't think you're too far off. I'm going to follow all the wiring looking for any issues, and if that yields no results then the only thing left to do is replace the trans computer. I'm fairly certain it's an electrical issue since I've ruled out everything else.

 

I agree you've done all diagnosing possible without getting into the computer aspect of the cars. I know the pcm controls the shift points of the transmission so there is a slight chance it could be that, but the other issues with the fob, could also be the key fob itself, the sensor under the dash that receives the signal or it could need a new security re learn, but a lot of times the bcm with is located above the parking break under the dash (I think it's the same for your year as mine) is the culprit, the pcm is located under the air cleaner inside the air box in the engine bay, maybe it wouldn't hurt to spray the connections down with a good aerosol cleaner from an electronics store and check the connections? small cost and not too much time to do and it may help

 

Sounds like you got more than one issue going on here. They fob has nothing to do with the tranny and the tranny is controlled only by the PCM. As for the overheating, did you clean the cooler lines? Didn't see a new channel plate gasket on your replacement list. Could also have an internal blockage in the tranny. Have you tried unplugging the wiring harness from the tranny and driving it a while? Be carefull to not go too far if you're having an overheating problem since you won't get a CEL or anything in the Message Center w/o the harness connected. This will distinguish between a PCM and internal mechanical problem. It seems like you know what you're doing to have done all this yourself and it must be frustrating. I find Dave at Triple Edge Performance to be very knowledgeable. I recommend giving him a call. Here's the link: http://www.tripleedgeperformance.com/
Keep us posted.

 

Plumbob,
Thanks for this, but I need a little more info, and I have some more info as well.

First, yes I have the channel plate gaskets, I forgot to list that. Actually got them from triple edge, metal not that paper kind. I also failed to mention originally that I also installed a new transgo shift kit.

Cooler lines were cleaned and I double checked that last night when I added a cooler. However I have ordered new lines because all the movement has caused leaks now. When I get the new lines I am tempted to remove the cooler, because I've never had an issue and I've had the car for 4 years.

As far as the fob, I know it isn't tranny related, but wondering if there is a greater underlying electrical issue. Or just a poorly timed coincidence.

Sidebar: Hadn't driven the car yet this summer, shut the hood on the rebuild, drove to the Secretary of States office (3/4 mile from home) registered and ready to go! and the fob dies, lock cylinder corroded shut, $65 to get it open... haha. So yeah you could say frustrated...

Now you say PCM and I assume that's what I'm referring as TCM or am I confusing two different things? Also, of the two computers in the air box, the larger with three plugs is the engine computer and the smaller single plug is the transmission correct?

Now you say unplug the transmission and drive it, are you saying the single harness into the transmission or do i unplug the computer?

Finally, for now, if I replace the computers should I get regular or just go straight to Overkill?

I really appreciate everyone's help. Glad I joined. Looking forward to getting my beast back on the road. Thanks

 

That helps. first of all the cooler. Unless your stressing the tranny by adding engine mods, racing, towing or extremely hot weather you don't need it. Just something else to go wrong.
The PCM is Powertrain Control Module and is the larger of the two in the air box, the TCM is Transmission Control Module. The TCM receives info. (signals, line pressure, temperature, etc.) from the transmission and sends it to the PCM. The PCM interprets that information, makes a decision and tells the TCM what to do to adapt to various conditions. Two different computers. Don't disconnect the connectors from the computers. If you do you will need to go through a relearn procedure. Do it at the connection into the transmission. A tech 2 scan tool is so helpful in trying to diagnose trans problems. I have one and you would be amazed by the info. it tells.
Another reason for high trans temperature is low line pressure which may be caused by a bad seal or line blockage. Even a bad seal on the filter can cause this. I highly expect this to be the problem, but again, talk to Dave. He's full of info. And I'm sure he'll be happy to talk to you, especially if you're a customer.
As for the fob, it does interface with the BCM but I think you'd be getting a code if there was a problem with it. Again the tech 2 is worth it's weight in gold. Since I have one I would buy a new fob on eBay for $15 and program it with the tech 2 or check for the code. Pretty hard to troubleshoot without it.

 

Thanks very much. I'll ditch the cooler and put new lines in and go from there. I almost ordered a tech 2 but my buddy's boss let me borrow his snap-on modis. It's unreal what you can do with those, so a tech 2 is definitely in my very near future. Low pressure is more the direction I'm leaning now since the car had no trouble codes at all aside from the code when it overheated, and it literally has nothing else wrong with it.

from what you've told me I think the fob is junk. I ordered new lines and we'll see what that does when I get them.

I will keep you updated. Thanks very much for you help.

 

Fingers crossed for you. I'm curious to learn what you find.

 

UPDATE!!
Status is better, but not great.

I pulled the lines, blew air threw the cooler, no blockage, lines are clear.

Pulled the filter which may have been causing some issue but not all. When I grabbed it, it moved and pulled out way too easily in my opinion (compared to the last one I pulled during rebuild).

Buttoned it up (no leaks anymore... little victories right?) and took it for a spin. Still not right. Almost red-lines going into 2nd, got into 4th one time and now it won't at all. Most recent drive it shuddered VIOLENTLY front to back going from 2nd to 3rd

I'm afraid the trans has to come back out. I think I need a new torque converter. Another possible issue (according the scanner) is a stuck valve in the valve body which is a joy to mess with if any of you have ever tried...

Unfortunately she'll be garaged until spring I think due to lack of funding to continue at this time... I appreciate the help I have gotten up to this point but we're on hold for now.

I'll post any changes and keep you all informed!