Car will not shift

Six cylinder front wheel drive 100,400 miles.
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At times the transmission will not shift into high gear.
Thus, at sixty five mph the tachometer is at 3500 rpm. Letting off on the gas, feathering the gas pedal, shifting into neutral does not help. At this point it is not a constant problem but it can only get worse. There are time is will fail to shift from a complete stop or, it will shift into second but not high gear. Any ideas?

I just found out this evening that I have the same problem with my wife's car. The symptoms are the same as yours.
If I find out anything I will post it here.

Regards,
Alan

Vacuum modulator. Remove this a check to see if it properly operates with a handheld vacuum pump.

I read other posts where the transmission was acting this way because the computer had turned off the overdrive because of ODB error codes. I was getting a couple of error codes, so I worked on getting rid of those first. Error codes are gone and transmission still does not shift into last gear.

I cannot find any information in the manual or online about the vacuum modulator. Can you tell me where it is, or any other name it may be called?

Regards,
Alan

Hi, I have the same exact problem and I need please someone to help me with that am about to go to the Lexus dealer because there is not way I can find out what is wrong.

I was getting P0171 and P0330 OBD codes. I cleaned the mass air flow sensor (MAF) with some MAF cleaner and the P0171 problem went away and the car started running nice again. The P0330 error code indicated that I had a bad knock sensor (bank 2, front of the engine). I took both knock sensors out and they passed the continuity test specified in the shop manual. I put it all back together and the car still would not shift into overdrive and was still setting the P0330 code. I took it back apart and replaced the indicated sensor as well as the sub-wiring harness that connects the sensors to the main wiring harness. That fixed the shifting problem and the P0330 error code.
The biggest downside of this was that I had to replace the $70.00 worth of gaskets again since I was not sure that they were reusable. They looked like they may have been single use crush to fit gaskets.

I also learned not to get parts from Lexus. Lexus has to buy their parts from Toyota, and then put their markup on that. Sometimes doubling the cost of the part. Instead, just go to Toyota and request parts for a camry.

Transmission is not shifting into highest gear - levels seem fine

Will not shift in high sometimes. I can pull over and put in park then take off and it is ok. Some times it works ok all day