This post is a continuation of my original post.
http://www.automotiveforums.com/vbul....php?t=1016652
I reposted it with a more descriptive title:
Updated info:
130k miles.
I am truly hoping that you wizards out there will tell me there is still more that I can try and that I don't need a new tranny. But I am not holding out much hope based on other threads I have read. I just spent about $1500 in parts and dozens of hours of my own labor this spring to get this car to a point where it was running perfectly, needed nothing and would last me at least another 2-3 years. Now I get THIS thrown at me !!!!!!!!!
Vehicle is back home. I had it scanned, confirmed the previous diagnosis: P0742 TCC / brake switch stays high.
Here are some more symptoms / observations / tests I have done since I am home now.
1. SES light is out (it was reset /cleared yesterday after the scan. The P0742 was the ONLY code set.
2. The transmission shifts beautifully through all gears, all of the time. The trans fluid is reasonably fresh, is bright red, and has no odor of burning whatsoever.
3. Driving it to work today, when TCC locks up (I presume a few seconds after getting into 4th, and not under much load) there is a noticeable "lurch / stiff shift" when it locks up. Not smooth the way it used to be. This only happens during lockup. The rest of the shifting is very smooth.
4. When the trans was functioning normally I used to be able to purposefully get the TCC to unlock by accelerating slightly and stepping on the brake to activate the switch. You would be able to hear the engine rev slightly higher when you stepped on the brake to "unlock" it.
It does not do this now. There is NO CHANGE in the engine speed when I do this.
5. That said, if I drop the shift lever out of drive and into "3", (I realize that the TCC won't lock up in "3"), and then do the same test as in #4 above, I
DO hear the engine rev (I presume from a slight downshift) when I step on the brake. Thus, I believe this proves the brake switch is good. Doesn't this also tell me that the TCC and solenoid are working ok as I can "manually" get it to disengage by shifting to "3" ?
What else can I do to further isolate this issue?
I found this on the internet:
http://autorepair.about.com/cs/troub.../aa061701a.htm
It appears to be a good troubleshooting aid, but I can't tell if it actually applies to the Venture Transmission. It only says "GM". Any thoughts?
Does my issue sound like it is (for certain) the TCC solenoid? Or could it be external? I hate the thought of a new transmission. This one works great except for this new issue. I have always maintained the vehicle very well and never abused it. I have had it since new.
I saw where one person tried some Seafoam for a hundred miles or so, and then had a full trans flush and said he had good success? Is this worth a try ? Or am I just going to add on another $100 cost for what is inevitably going to be a "new transmission"?.
Thanks for all your help.