Steering wheel on honda jazz very stiff , why and how do i fix it?

indicates a strut bearing problem and wheel alignment
take it to a power steering front end professional service center for a proper diagnosis

Cud b trans or wheel-steering issues..check fluid level..tires imbalance or lug nuts loose..motor mount old

hi Justine.
There some moments when the steering wheelbecomes stiff and hard to turn. From irregular servicing, lack of fluid oil to low tyre pressure or bad wheelalignment, any of these could be the cause. ... Under normal circumstances when the car is in good condition, the steering wheel is always flexible when turning.11 Sep 2014

What makes the steering wheel stiff? - Daily Monitor

www.monitor.co.ug/Business/Auto/What-makes-the-steering-wheel-stiff-/.../index.html
try this link.
Why Is My Steering Wheel Hard To Turn
or this.
3 Common Causes of Steering Wheel Hard to Turn Especially at Low Speeds...
or this one.
What causes steering wheel hard to turn

If the key wont turn at all, try pulling the steering wheel (hard) to either side while turning the key. Sometimes if the steering wheel locks in a certain position it will "lock" the ignition cylinder in place, and pulling away from the ignition will take the pressure off and allow it to move. IF this doesn't work, you may have a bad "ignition lock cylinder"

could be u joints in the steering column , rack and pinion out of adjustment or something binding up under the steering wheel

Boot repair kit from Napa.

Replace the pump and/or the rack and pinion.

- Disconnect the two wire connectors from the horn.
- Connect a test lamp across these two wires.
- Switch on the ignition, and press the horn button.
- If the lamp glows while pressing the horn button, replace the horn.
If the lamp does not glow:
- Check the fuse.
- Wiring.
- Steering wheel assembly.

they dont self centre. The car is epuipped with EPS (electronic power steering) so is controlled by a electric motor.
This is a characteristic of the car

possibly top bearing in steering Columm,get it looked at as steering could bind(jam)not for inexperienced people to try to fix dangerous