ELECTRONIC CONTROL SYSTEM RIGHT BANK INJECTORS X1 X2 X1 X2 LEFT BANK INJECTORS X3 X3 X1-6 GRD X1-13 EOPS X1 X2 IDM X1-14 V REF X3 EOPS X1-20 ICP X4 X2-3 MAP EGR DRIVE MODULE Functional Equivelant ECM ECM ICP VREF SENSOR BCS MICRO- PROCESSOR MAP IPR EGR VALVE REFERENCE VOLTAGE SWITCH Pressure Sensor Operation The Manifold Absolute Pressure (MAP) sensor, the Injection Control Pressure (ICP) sensor and the Engine Oil Pressure Switch (EOPS) are used to send pressure information to the ECM. change into a signal voltage proportional to the pressure being measured.
The ICP sensor is used to make corrections to the IPR signal and to continually check the performance of the Injection Control Pressure system. Engine Oil Pressure Switch (EOPS) The EOPS is used to detect oil pressure and is an input to the dash cluster and the engine warning protection system. The switch is normally open with the engine off but closes when oil pressure reaches 5 to 7 psi. The ECM sends 5 volts through a current limiting resistor to the EOPS and reads the voltage between the resistor and the switch. When oil pressure is low, the switch is open and the ECM reads 5 volts. The MAP and ICP are three-wire pressure sensors.
Three-wire pressure sensors receive a reference voltage and a ground from the ECM. The sensor returns a portion of the reference voltage, proportional to the pressure, back to the ECM as a signal. Manifold Absolute Pressure (MAP) sensor The MAP sensor is a variable capacitance style sensor. In a variable capacitance sensor, the pressure being measured deflects a ceramic disk towards a metal disk. The two materials make up a variable capacitor. Sensor mounted circuitry converts the capacitance into a signal voltage proportional to the measured pressure. The MAP sensor measures turbocharger boost in the intake manifold.
The MAP signal is input into calculations that determine fueling quantities and the desired EGR valve position. When the oil pressure is greater than 5 to 7 psi, the switch is closed, the circuit is shorted to ground, and the ECM reads a low voltage. When the ECM detects oil press- ure, MasterDiagnostics ® will display 40 psi. When the oil pressure is below 5 psi, MasterDiagnostics ® Injection Control Pressure (ICP) Sensor The ICP sensor is a Micro Strain Gauge (MSG) style sensor. The MSG type sensor has a small strain gauge that senses changes in pressure. Sensor mounted electronic circuitry converts the will display 0 psi. 30 International ® VT 275 V6 Engine