Power steering pump (turning wheel) makes engine rev up and down

There’s a tsb for this. Print this out and show it to them. https://www.tacomaworld.com/attachments/t-sb-0125-18-pdf.3132199/

 

^The TSB is intended for 2016-2017 trucks. It isn't like a mechanical TSB where the technician can go thru the same motions in hopes of fixing the problem. He can't flash @John F's 2019 truck with older ECM software.

Just make sure the dealer logs the complaint using the same buzzwords "engine idle surge with steering input". If enough people complain, Toyota may look into it. Not much you can do at this point. It's a minor annoyance anyway. You can start swapping PS pumps and steering racks, but it gets expensive really fast and may not improve things any.

 

What idle rpm were you at when it jumps 300-400 rpm with steering input?

Any air in the system? With the engine running, open the PS fluid reservoir. Turn the steering wheel side to side (without going into full lock) and see if the fluid gets bubbly.