2004 Nissan Altima Wanders at Highway Speeds

have an inspection done on the steering and front end suspension
loose /worn ball joints steering end joints , wheel alignment and faulty tyres will give you this indication
The power steering pump does nothing more that provide pressure into the steering box/rack to assist with the steering
it may be that the steering is to sensitive at speed and most systems compensate by having less power assist at speed
take it to a steering specialist accredited shop as the control valves may need replacing or adjusting

go to the service center . it may be faulty equipment that may make steering uncontrollable or unworkable.

if around 125,000 miles trans is going bad . possable bad planetary gears

vibration at highway speeds is normally a tire balance issue. take it to a tire shop and have them inspect and balance the tires.

Check your coolant level. If it is low, what you describe will happen. Water pump works faster as rpm's increase, managing to get hot coolant to heater core (highway speeds). At idle, pump is not working fast enough to get the coolant to the heater core.

Change the Throttle Positioning Sensor.
Clean the Mas Air Flow sensor with carburator cleaner, carefully.
Vitally

the vdc off can result because the steering input sensor needs to be re calibrated with the nissan consult2 .
the vehicle dynamic control uses input from the abs,vehicle speed sensor,air bag sensor,yaw sensor and steering angle input sensor.

Check your air filter & fuel filter first, how many miles do you have on it check manufactures suggested timing belt replacement recomendations

Depending on the tires, it could be a couple of things. I would have the alignment checked. If there isn't enough toe-in, you will get great wear from your tires, but the handling will be loose or will wander.

I had new tires put on our Nissan Maxima and they did a reallignment with not enough toe-in. It became very twitchy at interstate highway speeds. Just a little toe in made a huge difference. I knew what to ask for because I have some racing background. We could go faster with less toe-in, because it reduces the resistance on the rolling tires, but also makes it more sensitive to the road surface, side winds and tire wear.

But there also shouldn't be any slop in the tie rods, etc...

hi yes if its registaring 10 mile out it will be sending wrong information to the gearbox replace it with one that works yates210456