500 7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS
MAP Sensor (Manifold Absolute Pressure)
Figure 483 Function diagram for the MAP sensor
The function diagram for the MAP sensor includes the
following:
• MAP sensor
• Electronic Control Module (ECM)
• Injector Drive Module (IDM)
• Exhaust Gas Recirculation (EGR)
• Variable Geometry Turbocharger (VG T )
• Fuel injector
• ENGINE lamp (amber)
Function
The MAP sensor is a variable capacitance sensor
installed left of th e MAT senso r in the intake ma nifold.
The ECM supplies a 5 V reference signal which
the MAP sensor uses to produce a linear analog
voltage that indicates pressure. The ECM uses
the MAP sensor signal to assist in the calculation
of the EGR and VGT duty percentage. The ECM
monitors the MAP signal to determine intake manifold
(boost) pressure. From t his information the ECM can
optimize control of fuel rate and injection timing for all
engine operating conditions.
EGES-270-1
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
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