The 2017 is, I believe, a 3rd-gen Sienna. This is the 2nd-gen forum, specific to model years 2004-2010. We might not be well-equipped to answer your questions.

To at least get you started on some initial guesses…. If it’s not software, I wonder about bad connections in the wires. Again, total guess. These are also things that can potentially happen to any year, make, or model of vehicle.

- Rodent damage to wires? Do you live in a rural area or regularly park the vehicle in such an area? Do you ever see evidence of rodent poop or “stashed” seeds in, say, the air box? (These wouldn’t directly cause your issue, but they might suggest a related issue.)

- Loose ground wire? Do you know where the radio’s ground is connected? Sometimes it’s part of the frame just behind the radio’s mounting location. Regardless, it could be connected via a ground strap that’s fraying, and/or a screw terminal that is loose, corroded, or both. You would probably need to get behind the radio in any case. Same goes for the following…

- Liquid ingress into a wire or harness? I would initially check the harnesses behind the radio, since that’s closest to the issue. It’s less common for vehicles to get water behind the radio, though. Perhaps a connector in the engine bay? (You would want a wiring diagram though, specific to 3rd-generation Siennas, to narrow down where to look.)

Anyway, hope that helps you get thinking about potential trouble spots.

 

Thanks for the input. That's definitely beyond my range so I'd need someone at Toyota to do that for me. Unfortunately, as many people on the forum state, if the tech can't recreate the issue, then they typically can't resolve the issue. And since this is pretty random on how it works, it's something that's hard to describe let alone recreate.

Also, I'm sorry for posting on the wrong forum. I tried to delete it but couldn't. I just added the post to the right forum so it's with the Gen 3 issues now. Thanks!

 

No problem! I’m curious nonetheless. Also, I don’t blame anyone for not wanting to try radio removal, especially as cars get newer.

Returning to the matter of software, though… can you see if there’s a way to check the software version number? Then, see if you can find the version number of the latest update?
Assuming you haven’t already done so.

 

Thanks for the help. Do you know how to access the current software version on the console as well as the current version online? I went to Home | Toyota Software to see if there were any updates and I found none.

Also, I was able to recreate the issue tonight, but only once. Right after turning the vehicle on, I backed out of my garage and hooked the car, and then spun the wheel quickly the other way as I put it in drive. The car had a quick drop in power, the steering got tight (as if the power steering stopped working), and the radio blipped and reset as the power quickly returned to the car. I drove it for a bit with no issues, taking turns sharply. I even stopped in a parking lot, turned the car off, and then tried to recreate it again pulling out of a spot but couldn't get it to do it again. I checked under the hood and there are no leaks or frayed wires. To me, it sounds like perhaps a battery issue.

Thanks again for the help. I appreciate it.

 

Don’t Gen 3s have electric power steering?

Sixto
‘04 LE FWD 230K miles

 

I think so. Toyota’s press release for the beginning (MY11) of the 3rd gen Sienna mentions it has electric power steering. If so, pretty likely that all later ones do also.

Toyota Introduces All-New 2011 Toyota Sienna Minivan - Toyota USA Newsroom

DANA POINT, Calif. - -Since 1997 the Toyota Sienna has been well known as a transportation solution for moving people and cargo comfortably and efficiently. The all-new third-generation Sienna will look and drive more like a sedan, conform to new ideas about personal comfort, easily accommodate...

pressroom.toyota.com

12 paragraphs down the press release: “Electronic Power Steering (EPS) and a wider stance helps deliver a more solid direct on-road feel.”

I’m not sure if that’s an accurate description of behaviors attributable to electric power steering, but at least it does seem to indicate the 2011 had EPS.

I assume also that, once a certain make/model of vehicle has gone to electric steering for a given model year, they generally don’t switch back to hydraulic thereafter in subsequent model years and generations. Open to thoughts on that.

[Edit: Clarified “power steering” as specifically electric power steering.]

 

(Note: This post got long. TLDR: maybe a DC power issue. Get the 12V battery tested. You might want to trickle-charge the battery first, though. Consider getting a charger therefore. Also, use a voltmeter to check the battery voltage… with the car off, as well as with the engine running. My detailed ramblings commence in 3, 2, 1…)

The loss of power elsewhere makes me wonder about the DC power in the car generally. Have the battery and alternator checked - Auto parts stores generally have a battery tester that will at least do the battery. This battery check draws a bunch of current from the battery, which might therefore merit the purchase of a 120Vac-to-12Vdc trickle charger. Charge the battery before going to the auto parts store for the battery test.)

Do you know if this vehicle has electric power steering? 2017 is definitely the right era of vehicle for power steering. My previous ‘17 Subaru Impreza had electric power steering, for what it’s worth.

A temporary stiffness in steering, for an electric power-steering vehicle would suggest as above, a problem with the generation or delivery of DC power. That same issue could cause the input voltage on the radio to dip low enough to cause the radio’s computer to shut off, then come back on right after the voltage rises again.

So let’s talk about a few points regarding the generation and delivery of DC power in a car. Note:

First - is your battery newer than 5 years old? If so, don’t go out and buy a battery just yet. (I’ve done that before, with no troubleshooting data, basically replacing a nearly new battery for no reason. If it is in fact older than 5 years (a semi-arbitrary number, but safe given that car batteries should last 4-5 years, maybe up to 7 if you push it) then it could easily be weak, and/or losing one of its lead-acid cells.

Still, get it tested first. A good mechanic once told me to get data before throwing parts at the problem.

For troubleshooting, it’s be worth getting a battery tender/trickle-charger for car batteries. Wal-mart among other stores carry a low-current slow charger for $30-40. Schumacher Electric is a good brand that they often carry. Walmart’s own Everstart brand is worthwhile, too. I have several of their chargers in different capacities. And a Schumacher, also bought from Walmart.

(Side note: I get that some people feel iffy about shopping there. Any auto parts store should have these chargers, for probably not too much extra.)

I’m also curious about the following, which would require a voltmeter to check:

1.) Battery voltage: After charging the battery and disconnecting the charger (and without the car running), what’s the battery voltage? It should be 12.6 volts. Any less is iffy and would probably justify battery replacement. Check the battery again an hour or so later. It should not be any lower than the first check.

2.) Alternator voltage: What’s the voltage on the car’s 12V socket while the engine is running? Test it with the car in park (and brake on!) first. Test it again while in motion - This would call for you to sit in a passenger seat while someone else drives. (Please don’t do this yourself while driving! Don’t ask how I know.)

Ideally your voltage while the car is moving should be at least 14.0 volts. Often cars are 14.5 to 14.6 volts with a healthy alternator. With the caveat that one car I own, is normally 13.3-13.8 volts and apparently that’s normal per other owners. That’s a third-gen Mazda Miata though… a little different from your ‘17 Toyota minivan!

If your engine-running voltage is less than 13 volts, I’d be concerned about the alternator. A bad alternator can also kill a battery over a short time… so that’s part of why you might not want to just replace the battery even if it’s bad. You might be replacing it again in a few weeks if you don’t get the alternator tested.

I have tested some alternators… butmy experience here is limited beyond low voltage. I have an OBD2 reader that has an alternator test mode where it guides you through some activities that should put load on the alternator to see if it underperforms at load. Having said that, I’ve only tried it with a few vehicles, and never uncovered a bad alternator in doing so. For that reason I won’t tell you to buy an alternator tester at this point, since I don’t know enough to tell you if it’ll help.

But anyway, gather that data and report back. Charge the battery with a battery tender, then get the battery tested (free) at an auto parts store. Two or more stores if you have time. Go during the day, and you might get more-experienced staff. Have them test the alternator if they have the ability. Check the battery voltage also, both with the car off (and charger disconnected) and with the engine running.

There are other possibilities, but let’s start here.

 

I definitely think it’s the battery or alternator, and I’m leaning towards battery, both out of hope and experience. I’ve had an alternator go in the past and it usually kills the battery to the point where the car won’t start again. That doesn’t happen here.

It feels like with a surge in power (low speed steering where the PS takes a lot or when you gun it at high speeds), it seems to happen. 99% of the time the car runs normally and it only happens for a matter of seconds.

I’m going to take it to an AutoZone where they’ll check both the battery and alternator, but I feel like it’s the battery.

It’s just a strange thing that I’ve never experienced before, but I’ve never had a car with electric power steering and that probably draws a lot.

 

Did you ever figure out what it was?? My 2016 Sienna is doing the exact same thing as yours was.

 

Does it have a mechanical key switch?

Sixto
‘04 LE FWD 230K miles

 

@helpyak Did you ever figure out what it was?? My 2016 Sienna is doing the exact same thing as yours was.

 

This looks like a gen 3 forum...
My 2015 audio started acting up and then stopped working altogether. The backup camera works fine. I called a shop who indicated it might be the touch screen. a $400-$600 repair. Any others have this issue or a solution?