Usage:
System Operation
The ECM system monitors inlet manifold (boost) pressure with a sensor located at the front of the engine on the right cylinder head. The inlet manifold (boost) pressure sensor is supplied with electrical power by the 5 volt reference voltage from the ECM.
The inlet manifold (boost) pressure measurement is used to reduce smoke emissions during acceleration. The ECM limits the amount of fuel injected until certain inlet manifold (boost) pressures are reached. It does this by converting inlet manifold (boost) pressure to "FRC Rack" (as shown on the ECAP status display). The FRC Rack (Fuel Ratio Control) is then a limit on rack position based on inlet manifold (boost) pressure.
The ECM inlet manifold (boost) pressure sensor must be calibrated for a zero boost condition with the engine off. Calibration is accomplished electronically without the need for manual adjustments.
NOTE: The Boost Pressure Sensor and Oil Pressure Sensors are indentical and can be interchanged.
NOTE: The Boost Pressure Sensor must be recalibrated automatically using an ECAP whenever the ECM or boost pressure sensor has been replaced in order to avoid poor engine response.
Schematic
Diagnostic Codes
Functional Test
