Mat Sensor (Manifold Air Temperature) - Navistar International DT 466 Diagnostic/Troubleshooting Manual

508 7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS

MAT Sensor (Manifold Air Temperature)

Figure 488 Function diagram for the MAT sensor
The function diagram for the MAT sensor includes the
following:
• MAT sensor
• Exhaust Gas Recirculation (EGR)
• Electronic Control Module (ECM)
• ENGINE lamp (amber)
Function
The MAT sensor is a thermistor sensor installed
right of the MAP sensor in the intake manifold. The
ECM supplies a 5 V reference signal which the
MAT sensor uses to produce an analog voltage that
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
indicates temperature.
resistance when exposed to different temperatures.
As air temperature decreases, the resistance of
the thermistor increases.
voltage to increase. As air temperature increases, the
resistance of the thermistor decreases. This causes
the signal voltage to decrease.
The MAT sensor provides a feedback signal to
the ECM indicating manifold air temperature. The
ECM monitors the MAT signal to determine if the
temperature is satisfactory. During engine operation,
if the ECM recognizes that the MAT signal is greater
or less than the expected value it will set a Diagnostic
Trouble Code (DTC).
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
The MAT sensor changes
This causes the signal