Are you the original owner of this vehicle? I'm afraid the valve body has to come off to replace the solenoid.

Yes, I'm original owner since 09 miles! Yeah, that's what I thought. I heard it was 6 bolts holding the body. Do I absolutely have to replace the valve body gasket? My parts guy said no -- not necessary. Are the bolts directly above the oil strainer and easy to access?

How do I remove the valve body carefully without damaging anything.

Atx Is Fixed!!!!!!!!!!!!!!
 

:git: ATX IS FIXED!! Removed the driver's side belly cover and dropped the trans pan and there were ALL the solenoids staring at me and easily serviceable -- without dropping the valve body! One 10mm bolt secures the EPC solenoid onto the solenoid assembly of the valve body. It is sealed in the valvebody with a small o-ring (comes with solenoid).

I OHM'd the solenoid directly on the vehicle and it read DEAD OPEN between both terminal A & B; the ATX case wiring harness (9-pin) terminals (D & I) already confirmed this reading before I started anything.

Remove 10mm bolt and wiring harness. Then carefully pulled out solenoid horizontally; you will get some resistance from the o-ring seal... just pull smartly and be careful of sharp parts!

Install the new solenoid by lubricating the o-ring with new ATX fluid and follow the above-stated directions in reverse. Push in solenoid gently and it should snap in place on the valvebody. I tested the new solenoid and it passed with a reading of 4.4 OHMS (normal = 2.4-7.2).

Since the fluid looked deteriorated (cloudy, dirty reddish), I changed the filter too. Really easy! Pull down old filter and put a new o-ring (or reuse old one) on the integrated pipe. Lube the o-ring with fluid. Gently push back up into assembly and reattach TFT sensor. Cleaned pan and magnet (pretty dirty after only one year). Reattached pan with black RTV (pain in the butt) and torqued bolts gently. Don't overtighten otherwise RTV is sqeezed out! Change the trans pan drain bolt crush washer. Don't reuse the old one! Don't overtighten drain bolt!

Fill up with new ATX fluid (Dextron III) at the dipstick orifice with EXACTLY the same amount of fluid drained during the service -- I got about 4 qts. Start up engine and check for leaks and fluid level. Carefully change gears -- WITH ALL BRAKES ON -- to get fluid in all channels and check fluid again and again. No more O/D light flashing and ATX shifts perfectly! Happy repairing people!

UPDATE: Road-tested for about 20 miles; the transmission feels like it just rolled off the new car lot -- silky smooth gear transistions; smooth and solid up/downshifts. The car's powertrain is quieter. Re-scanned PCM/TCM and no codes were present. The DTC clears automatically after a few start-up cycles and no faults. Plan to change fluid again in about one year or so.

FYI: I have hi-res photos of the service but they are too large to attach. PM me.