I was driving home yesterday and my check engine light came on.
I stopped by Autozone and they checked for a code and it came out as a P0550 Power Steering Pressure Circuit Malfunction.
I'm guessing the sensor is bad. The Power Steering fluid was full and the car drives fine.
Does anyone know where the location of the sensor is so I can change it out? And would I have to use a dealer sensor?
Will I have to reset anything to clear the light after I fix it?
Please advise and thanks.

 

Interesting that this is still happening with newer Mazdas. My wife's 1993 Protege has had the same problem almost from the beginning and nothing was ever wrong. They told her to drive with the light on and she did. She put on thousands of miles and the light is still on LOL. I'm thinking sensor problem. I tried disconnecting the battery for a few minutes and reconnecting it. All that does is cancel the engine light until you restart the engine, then it's back on. My thoughts only. Have a great day.
RM

 

The PS pressure switch is on the body of the pump. There's only one wire connected to the pump, so it's easy to find. Try resetting the codes by disconnecting the battery -ve with the car door open so the courtesy light is on, wait 30 seconds and reconnect the battery. Now drive with the wire disconnected. Your CEL should now be off unless you've got a car side wiring short to ground.
The other thing you should check is the tension/condition of the PS pump drive belt; if it's not up to snuff it will cost you PS pressure. (The PCM checks the status of the PS pressure switch contact (open) when the car is at 60 kph or more and the engine temp. is 160F or more).