We have a 2012 GX460 and had the following problems: P0761 Shift Solenoid C performance. And P2714 Pressure Control Solenoid D performance. It wouldn’t shift into 4th gear when driving. So we were comfortably limited to about 50-60mph. Also it wouldn’t shift. Last year, we had taken it to a couple transmission shops and they told us the same thing (replace the tranny for $6-8k)….
Yesterday, we drained the fluid (the “overflow” plug was first opened (about 1.5 qts came out <— big red flag). Then the main drain (about 3 qts <— expected).
When I removed the pan, tons of AT fluid on the wires and solenoids (indicating they were swimming/drowning in AT fluid). Very little metal on the magnets (about a dab of metal fines collectively a paste about the size of a grain of rice).
I cleaned all the solenoid terminals with carb/choke cleaner (best I could find easily, but I’m sure some sort of electrical terminal cleaner would be ideal). Then tested all the solenoids for continuity (13.5 -14.5 ohm) and actuation using 9v battery: S1, S2, S3, S4 would make a distinct click, while SR did not make the click. So after a little thinking I contemplated if SR needs Hydraulic Pressure to actuate against.
Next step (properly fill with the “overflow” plug open). We filled with cold fluid until overflow; then plugged the overflow, then warmed up the transmission fluid, then opened the overflow plug to confirm proper fill.
Test drive confirmed shifting on all gears; including reverse works. We will continue to test, but some simple (low-cost steps):
1) check your transmission fluid level is proper. Solenoids and terminal connections don’t seem to perform well in AT fluid.
2) if you drain and remove the pan, check for metal on the magnets. Then clean solenoid terminals with some spray that is safe for cleaning electrical terminals and evaporates fairly quickly.
3) test solenoid terminal continuity using a multi-meter (check your spec’s for proper resistance).
4) Test solenoids for proper actuation.
5) replace pan and fluid; be sure to fill to proper level and check when warm.
Hope this long summary helps encourage someone out there who is struggling with the same problems.
And by the way, removing the SR solenoid is very easy: Simple electrical connector button and one 10mm bolt. Tons of videos on youtube to remove them.
Thank you for having this forum. It’s been very helpful for me over the years.
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