Shift Solenoid Slt Test

[LabMonkey]

2000 LS400 A650E. I received the P0770 Shift Solenoid E code. My searches indicated that it was Shift Solenoid SLU. I found and performed the test procedure with the 8 watt bulb, variable supply etc. The SLU solenoid moves as predicted without issue. The SLT solenoid does not move with the lamp in series with the supply. Take out the lamp and it moves full travel at 1.1A 6V. Apply 12.5V and it draws 2+ amps. The resistance of the coil is 5.7 ohms. I would suspect that the SLT solenoid is binding if the test is the same as the one for the SLU, but the code is for the SLU and there are no codes for the SLT. The test only requires that the solenoid extend and retract. The SLU extended, but not full travel with the lamp in the circuit. I expected full extension, but that may not be required to pass the test. Any thoughts?

Thanks

[LabMonkey]

Update: I pulled the enhanced codes P1755, P1760 and P1765. These are codes for SLT, SLU and SLN shift solenoids. Basically I'm getting codes for all three pressure related solenoids or their circuits.

[landar]

Hmmm...and the fluid is fresh? I can not see all three solenoids going out unless it was pretty sludged up in there.

Maybe its faulty power train computer drive to the solenoids?

[LabMonkey]

Update2: I replaced the SLT solenoid due to the questionable bench check. All seems to be well now. No codes and normal shifting. The transmission pan is a pain to remove and install, so I'll probably have to make a gasket for it if the "blue glue" got rubbed off. Now on to the leaky steering rack, valve cover gaskets, timing belt, rear struts, trunk rust...

[LabMonkey]

P.S. if the trans code(s) come back I'll start with the wiring and ECU before pulling the trans out.

[scraape]

any update on what ended up happening with this vehicle ?

[Silverboat98]

I just did my valve body harness because my VVTI was not working properly as well as the SLT solenoid because the connector was cracked and the SLN solenoid because of harder shifting. I must say the shifts are a lot smoother and my VVTI is working too. I bought both from lexuspartsnow.com for my 98.