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Car and details:
(2000, V70XC AWD turbo w/144K+, DOM- 10/1999, B5244T –5 Cyl., L5, AW50-42LE Transmission.

All B- ground points were removed, cleaned and reattached. The B+ ‘starter’ cable clamp terminal (cable from battery to starter to alternator), due to unseen corrosion of the cable at its terminus, reached over 200 degrees F. I replaced the B+ starter cable. Save for some small, stupid issues in the past, the car has been running well).)

I had the P0743 ("Torque Converter -Clutch Solenoid -Circuit Electrical") come up several months ago and without incident. Recently, I stopped at a signal light. Car went to idle. I felt a subtle 'relaxation' from Drive, come from the car. The signal turns green and I hit the accelerator. The engine revved up, but the car stays put. I ran the shift selector through the gears to no avail. It wasn't until I turned the engine off for a moment, then started it again the transmission shifted through the gears properly. This was normal driving mode - not "limp home.”

Other than the "Check Engine" indicator, there are no other indicators (i.e. - the "Low gears" arrow). When engaged and running, the shifting sounds and feels normal, no hard shifting while either starting up or through the normal shift changes.

I went through VIDA troubleshooting and checked the associative Volvo ODB2 code to the P0743:
P0743 (generic)> “PS System Stuck Off” > Volvo code= TCM-0054

I accessed the AT signal connector cable on the trans body and electrically checked the resistance of the solenoids. According to Volvo, solenoids S1, S2 and SL should have a resistance value in the range of 10 – 15 ohms. S1 and S2 both measured =< 15 ohms. Solenoid SL measured 27 ohms.

By virtue of the fact that the SL solenoid was so far out of spec (80%), I changed it out (Side note: What a pain in the A*s that was and what a tease. If you look down at the Control system cover, you’d think that there was enough room to move the cover out, then rotate it upward to remove. I ended up doing a modified disassembly and dropping of the sub-frame, but it was still a pain).

I kept tabs of the transmission fluid volume that drained (BTH – Dexron III or IV for the AW50-42LE) and took note of the color and odor. The color was charcoal grayish and the odor smelled like most hydraulic fluids (maybe not having that ‘sweetish’ odor, but I didn’t think it smelled burnt, like burnt oil). I pulled the bottom drain plug, cleaned off some very fine metallic debris that had been drawn to the magnet, then made several flushes of fluid amounting to a little under eight Liters (Pennsoil AT fluid, Dexron IV, et. al.).

(Sidebar: By the way. I did this during the latest heat wave on the Central East Coast. Does anyone work on his or her cars when the weather is great?)

After the AT fluid change out and finally checking the proper fluid level while at a temperature of 37degrees C, I moved it out onto the main driveway and shifted through the gears. Seemed OK. Moved out onto the street and went through the moves. Worked OK, then, while in drive and breaking, I felt the torque on the car change. The issue was still there.

So, any clues anyone? I have to go back through VIDS and see if I missed something or brushed some symptom off. A neighbor suggested changing out the main AT filter. That’s not too big a problem (I say now) that I’ll just do that as a matter of course.

Most of the posts I’ve see about the AT, talk about the hard shifting (the dealer did do the firmware upgrade) and the low gear arrow indicator coming on. I’ve had none of these problems.

That the transmission ‘resets’ itself when I restart the engine is a key, I believe. The contacts on the AT signal connector all appear in good condition. I’ve not yet pulled the computer module to check those. HELP would be wonderful.
Dennis
 

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I think it's history.
I had a similar issues with a very good 2000 with 104K miles about a year ago.
It went from throwing a soloniod code to complete junk (no movement whatsoever) in 300 miles.
Besides the electrical issues on yours, the guts are 140K miles old and probably worn out now.
$700 for a good used tranny and a year later the buyer is still a happy camper. :thumbup:
 
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