if you have the F2 mazda, the sensor is next to oil filter, easy to replace. If you have the GM then thats a bit more tough that sits horizontal agianst the block on top of filter housing but its easier to remove air filter housing, ecu and injector module to replace oil psi sender. make sure connector is good also cause that will cause the fault also, good luck

The oil filter on these trucks is awkward to access and if you do manage to get it loose you tend to pull it up past the air filter and gas and vacuum tubes to the regulator pulling against the oil sender wiring connector which then cracks the body of the sensor unit and then you end up with this code.

Nero

my book says this is the engine oil pressure (sender) out of range. have you considered changing the oil, oil filter and oil pressure sender?