What is responsible for hardness in pow steering of toyta sienna 2005

It's listed on the label in the driver's door pillar area.

http://ricksfreeautorepairadvice.com/whats-the-correct-tire-pressure/

you may have to consider the 2005 pump that is made for the 2005 engine

Was a problem on pre 2000 in cold weather but yours might be dirty power steering fluid.

fuse box. check em. (both boxes)

Hello and thank you for asking me, the most common cause for this is a loose/slipping power steering belt so it should be inspected and adjusted or possibly replaced. This engine has two drive belts, one for the alternator and a/c and another one for the power steering, if one is worn or loose it's best to replace both belts. Let me kno wif you have any more questions or additional info.

On this website, you find fuse box diagram and description for Toyota Sienna (2003 - 2005)

Toyota Sienna Second Generation mk2 XL20 2003 2005 fuse box diagram Auto...

The owners handbook states that it indicates a malfunction of the air bags and advises to take the car to a dealer.
But.. sometimes a dodgy connection can cause this on a lot of cars. Sometimes the connectors located under the seat cause trouble on many. Also, the connection to the steering wheel air bag.

To make sure this isn't a one off, you can disconnect your battery for 15 minutes then reconnect. See if the fault clears.

If it doesn't then there's a fault most likely. Whilst the battery is disconnected, have a check of the seat connections if you can.

If there is an SRS fuse, you can just remove that to disable the airbag system, rather than disconnecting the battery itself. This way you don't loose your radio settings etc.

Hi, first thing is to check the power steering pump reservoir to see if its empty. if so, fill to specs. if the problem still exist, make sure the power steering belt is tight and is free spinning and the pulley is working as well.

You probably do have a power steering leak. Check the fluid again, it's most likely low if you are having an increasing problem with it. As the fluid is drained slowly through the leak it allows air bubbles to enter the system and cause it to become sluggish or sticky. Get the leak fixed asap so you don't spend a huge amount on fluid and keep an eye on the fluid level.

Most likely the problem is the lower steering knuckle. This is the one outside of the firewall, under the vehicle and it hooks up to the power steering assist cylinder. In my opinion the knuckle has to work at an unreasonably steep angle and this compounds the problem. The knuckle (especially in salt areas starts to corrode and becomes hard to turn. Toyota says the water gets into the bearing and they beings to rust the bearing and turning the whell starts to feel stiff. I have this problem and I sprayed liberal amounts of a rust inhibitor that a local place uses to rust proof cars (They sell small spray bottles of it for $5). They are called OIL TECH in Barrie, Ontario and make up their own formula. The formula has addatives that breaks the surface tension on the oil treatment and gets it into the tiny cracks and crevices on your vehicle. I sprayed this all over the knuckle, turned it back and forth a couple of times and continued spraying. I let it sit for an hour and went for a test drive -- problem solved. You could actually see the rust on the exposed parts of the knuckle. I probably will have to do this once every month of two but what the heck. It is a lot cheaper than having to replace the steering shaft ($1000+???) Probably other types of rust proofing or lubricating oils will work. I long for the old days of grease fittings and you never had to replace ball joints and tie rod ends etc.
Norm