Circuit DescriptionThe exhaust gas recirculation (EGR) differential pressure sensor has two ports that sense exhaust pressure. The sensor outputs a voltage which represents the pressure difference between the two ports located across an orifice in the EGR tube. The engine control module (ECM) uses this pressure to determine how much exhaust gas is flowing in the EGR connection tube to the intake manifold. This information is used to control the EGR valve for correct emission levels.The ECM provides a 5 volt supply to the EGR differential pressure sensor on the sensor supply circuit. The ECM also provides a ground on...

Circuit DescriptionThe 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 in the center of the shaft. As the flat on the turbocharger shaft spins past the speed sensor, a signal is generated. The Engine Control Module (ECM) interprets this signal and converts it to a turbocharger speed reading. Component LocationThe turbocharger speed sensor is mounted in the center housing of the turbocharger. Conditions for Running the DiagnosticsThis diagnostic runs continuously when the engine is running. Conditions for Setting...

Circuit DescriptionThe circuit is a pulse-width modulation (PWM) driver in the engine control module (ECM) that controls the fuel pump actuator. The actuator is grounded in the ECM. The actuator is normally open. The PWM duty cycle to the fuel pump actuator depends on the difference between desired rail pressure and sensed rail pressure. Component LocationThe high-pressure fuel pump is mounted to the gear housing. The fuel pump actuator is mounted on the fuel pump. The fuel pressure sensor is mounted in the high pressure fuel rail. The fuel pressure relief valve is mounted on the high pressure fuel rail....

Circuit DescriptionThe crankshaft position and camshaft position sensors are Hall effect type sensors. The engine control module (ECM) provides a 5 volt supply to the position sensor and a return circuit. As the teeth on the crankshaft speed ring or the dimples in the back of the camshaft gear move past the position sensor, a signal is generated on the position sensor signal circuit. The ECM interprets this signal and converts it to an engine speed. A missing tooth on the crankshaft gear is used by the ECM to determine the position of the engine. Component LocationThe crankshaft position and...

Circuit DescriptionThe engine control module (ECM) provides 5 volt supply to the engine camshaft speed/position sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The camshaft speed/position sensor provides a signal to the ECM on the camshaft speed/position sensor signal circuit. This sensor generates a signal to the ECM as the camshaft speed indicator lobe moves past the sensor. The ECM interprets this signal into an engine speed reading and determines engine position. This sensor is used as a backup sensor if the primary engine crankshaft speed/position signal is lost. Component LocationThe...