problems with trans codes

[easytoremember]

car is a 96 Grand prix with a 2000 Grand Prix 3800 Supercharged engine trans pcm etc.

Three codes:

P1860 TCC PWM Solenoid Electrical
P0753 1-2 Shift Solonoid Electrical
P0758 2-3 Shift Solonoid Electrical

Fuse isn't blown.

I checked the wiring by beeping out the wires from the trans to where they go, either the PCM or the fuse box, they all beep out for continuity just fine, so no broken wires.

I also checked all three solonoids to make sure they click when I give them ground, they do.

Replaced the PCM.

even followed the diagnostics in the Mitchell On Demand, can't find the problem.

what am I missing...

[Russ Jerome]

Have you put an actual load on the power side, that is energize a headlamp or something using that same source to make sure the power side is strong (12v under load). Audible tone from your meter is saying its reading continuity but there may be a weak power source not showing up on the solenoid driver side like corrosion or a rubbed wire. I like to use a headlamp, few turn bulbs and misc solenoids all at the same time to test a power feed, my combo of components tied together draws 13 amps or so, if a wire feeds that load it will surely feed a solenoid.

[easytoremember]

So ur saying splice into the feed wire and run it to a headlight to see if it is powerful enough to power a headlight? Nope haven't tried that. Interresting idea. Might try that. Might just also run a new feed wire, something is telling me that there might be a break in the wire that isn't noticeable until the car is moving, then I'm not under the hood, but behind the wheel so I don't see it, but the pcm is

[Russ Jerome]

Exactly, you are duplicating a load on the wire rather than just a signal generated from your 9v battery in your meter. Your bypassing the feed power works great as well, even if temporary just to verify the problem. Being the only thing the 3 codes have in common are the 12v feed to the solenoid your definately on the right path. Beyond that if one of the coils is drawing a huge load and remains powered before the next it could cause and issue but you would have to read what order they power up or remain powerd. An inductive amp clamp is usefull if thats the case but a voltmeter will work.

[wrencher]

I have seen connectors & internal harness issues with these b4.

[easytoremember]

figured it out. stupid bad solder connection on the lead wire. fixed and almost all is better, now trying to figure out why it feels like a misfire under heavy boost.

If I go from crusing at 40 then stomp on it, it sputters like a misfire, but the HPTuners doesn't register a misfire. if I ease into it off the line all is fine..... urgh no rest for the wicked.

[Russ Jerome]

Lean misfire under boost? Wide band or O2 readings?