Took my 2000 RX300 to a transmission shop a few weeks ago and my transmission was rebuilt at a tune of $2700 — but within 15 minutes of driving, the CEL went on so I brought it back. Code returned is repeatedly P0765 Shift Solenoid D. Trans guy said he replaced D valve twice. CEL and P0765 continues after returning to the shop two more times and test driving with OBD hooked up, which showed the shift gears operating. Trans guy suggests its electrical, specifically the ECU. He even suggests the CEL stays on because of a burned out marker lamp at left front tire. Because he is so insistent, we take it to an auto electronics specialist and he checks it out and says the electrical is intact and it’s an intermittent problem somewhere within the transmission. He also test drove it from Kalihi to Pearl City (25 miles RT) with the OBD hooked up. The trans guy is reluctant to honor the warranty and keeps reiterating that he replaced the D Solenoid twice! Which beg the questions: 1. where did he get the rebuilt transmission? 2. How many miles was on it? 3. Did he use new or used parts in the first and second replacement for the Solenoid D/valve? 4. Aren’t these valid questions to ask a mechanic? I paid the $2700 plus another several hundred to the auto electronics specialist.
Anyone on island experience a similar problem with their RX300?
(I love my car and originally bought it for the utility, i.e., no transmission hump in the back seat which makes it so practical for interior design and staging. It had been very well maintained and was at 198K miles before trans started to go. I owned a newer model RX350 for a year and an ES300 sedan for 3 years and sold both of these back to dealer but always held onto my RX300.

Anyone anywhere experience a similar problem? Appreciate any feedback or info concerning as I learned a lot about my car reading through posts on the clublexus site. Mahalo!