However, like any system it can have its issues.
On the electrical side the system demands a high current from the battery, so if the battery is tired or the connections are dirty/loose, you will experience issues with the steering.
There are also a pair of connectors under the airbox (just where the coolant tank overflows) that can also get corroded or loosened if someone's been working nearby.
In extreme cases this may cause the steering warning light to appear, but intermittent connections may just cause a sudden loss of power assistance - the steering still works but is heavy.
If this happens to you, check the battery and its connections first.
If these are okay then it might be the main body earth point - follow the black lead to here
and check that this is clean and tight.
The other, more common, issue is that the universal joint at the bottom of the steering column gets dried-out by the heat from the exhaust manifold and this can make the steering stiff, either constantly, or intermittently, sometimes in one direction more than the other, something just off straight-ahead in either direction.
Even if you're not yet experiencing steering issues, it's a good job to give this joint some lubrication.
Note that this issue doesn't appear on the US Mazda forum, as their steering is on the other side, well away from the exhaust
To lubricate the joint...
- - jack the front of the car up so both wheels are off the ground
- remove the driver's-side wheel to give clear access
- unclip the rubber flap (equivalent to the one on the nearside for the plugs)
- locate the steering column and follow it down to the UJ
- put the key in the ignition to release the steering lock
- turn the steering wheel from lock-to-lock and feel if there's any resistance
- it should spin freely and a quick nudge should send it all the way. (it probably won't)
- get a can of motorcycle chain lubricant (any brand as long as it's suitable for O-ring chains)
- spray a generous coating over the UJ, turning it around by push-pull on the front disc.
- repeat the 'turning the steering wheel' check and you should find that the action is much freer.
- replace the rubber flap and front wheel.
You might have noticed an increase in "tramlining" or be finding it difficult to hold a smooth line on tightening or opening bends.
This is because, when the UJ dries out, there's a major increase in stiction (static friction) which then causes you to over-correct minor steering inputs as you overcome the initial resistance.
This process is also good for fault finding as it shows that the mechanical side of the system is sound, assuming there are no clicks or tight-spots afterwards, and any further issues are likely to be electrical.