Theory Of Operation

The Turbocharger Speed Sensor is a variable reluctance speed sensor. It consists of a coil of wire and an iron core. The target on the turbocharger shaft is a ground flat surface in the center of the shaft. As the flat surface on the turbocharger shaft spins past the speed sensor, a signal is generated. The Powertrain Control Module (PCM) interprets this signal and converts it to a turbocharger speed reading. This monitor is a two trip fault. The MIL lamp will turn off once the diagnostic runs and passes in four consecutive drive cycles.