A high pressure sensor has been developed for use in common rail diesel fuel injection systems. This sensor uses a stainless steel diaphragm for fluid compatibility and operates at very high pressures (up to 26,000 psi or 180 MPa). Advanced diagnostic and protection functions are included in the electronics to alert the electronic control module of possible sensor failures. All signal conditioning functions are integrated into a single CMOS integrated circuit to reduce cost, size, and complexity. Diesel direct injection (DI) engines based on high pressure common rail fuel injection systems using these pressure sensors offer improved fuel efficiency, reduced emissions, and other benefits.