Bap Sensor (Barometric Absolute Pressure) - Navistar International DT 466 Diagnostic/Troubleshooting Manual

314 7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS

BAP Sensor (Barometric Absolute Pressure)

Figure 383 Function diagram for the BAP sensor
The function diagram for the BAP sensor includes the
following:
• BAP sensor
• Electronic Control Module (ECM)
• Injection Driver Module (IDM)
• Fuel injector
• Exhaust Gas Recirculation (EGR)
• Variable Geometry Turbocharger (VGT)
• ENGINE lamp (amber)
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Function
The BAP sensor is a variable capacitance sensor
and is located in the cab. The ECM supplies a 5
V reference signal which the BAP sensor uses to
produce a linear analog voltage signal that indicates
pressure.
The primary function of the BAP sensor is to provide
a feedback signal to the ECM to adjust timing and
fuel quantity. The ECM monitors the BAP signal to
determine altitude, adjust timing, fuel quantity, and
inlet air heater operation.
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.