98.5 24v:
Well I replaced my white center plug witha gas one. I removed all unnecessary wires and used what the old plug did. Soldered all new wires to existing harness and well my problem persists.

My truck still leaves a dead stop in 2nd or 3rd gear. Has brand new valve body since trans shop that was issue. Found if I tinkered with wires on plug it would sometimes work. Well has new wiring from plug and still messed up. This is my only problem with trans. Every other gear shifts smooth and at good RPM.

There is a way to get it to work. If I start the truck and while the abs, brake, CEL, and the other lights that come on during start up, if i put the truck in drive before all those lights shut off it will go into first gear. I'm not sure what it means its obviously electrical. Also when I do this the truck will have a 'lope' to its idle for a few seconds. Obviously its not good to put in drive like that right away but it will go into first gear after I do that.

Also, when I do get it to shift down correctly, if i sit at a stop light for a period of time you will feel it upshift while you sit there into second gear.

Another thing that I've noticed happen since all of this has started is my cruise control light does not illuminate on the dash when I push the button the wheel. The cruise will still work kind of a guessing game to use without a light and sometimes it doesnt always work when you push the on/off button for the cruise. takes mulitple times sometimes. I assume the pcm controls the cruise. Didn't see anything on the middle pcm plug for cruise wiring but I didn't look at other plugs since my GP issue was caused by the middle plug.

My question is what else can I do rule out a bad PCM because as of right now that's my conclusion. And any insight on whether this is a good conclusion would be awesome because a new PCM is not cheap.

Thanks in advance. I'm extremely frustrated at this point right now. Seems like I'm the only one who's ever had this problem persist with the parts I have fixed and replaced.

 

PCM setting any codes?

Checked the harness from trans, to PCM?

Speedo working properly?

Trans output speed sensor working?

 

No PCM codes. Completely check harness from PCM to trans redid the center plug that controls the trans functions.

Speedo works as it should. It reads about 5-10mph off of my actual because of my tire size.

Replaced trans output speed sensor less than 3 months ago chasing this problem.

 

Need to do some data logging, both while it is working, and while it is not, and see if anything presents itself.

Sure sounds like a sensor problem though.