
RENR5622 67
Troubleshooting Section
•
Coolant temperature sensor
•
Crankcase pressure sensor
•
Filtered engin
e oil pressure sensor
•
Left turbocharger inlet pressure sensor
•
Right turbocharger inlet pressure sensor
•
Turbocharger
outlet pressure sensor
•
Unfiltered engine oil pressure sensor
The supply voltage is routed to terminal A of each
sensor connector. The sensor return is routed to
terminal B of e
ach sensor connector. The sensor
signal is routed to terminal C of each sensor
connector. The ECM provides short circuit protection
for the intern
al power supply. A short circuit to the
battery will not damage the internal power supply.
The ECM perfo
rms an automatic calibration of these
sensors whenever the ECM is powered and the
engine is off for at least five seconds. During an
automatic c
alibration, the ECM calibrates pressure
sensors to the value of the atmospheric pressure
sensor and against an acceptable offset pressure
range.
The ECM continuously outputs a pull-up voltage on
the input te
rminal from an analog sensor. The ECM
uses this pull-up voltage in order to detect an open or
a short in the signal circuit. When the ECM detects
the presen
ce of a voltage that is above the normal
range of the sensor on the signal circuit, the ECM
will generate an open circuit diagnostic code 03 for
that sens
or. When the ECM detects the absence of
the pull-up voltage on the signal circuit, the ECM will
generate a short circuit diagnostic code 04 for that
sensor. T
he presence of pull-up voltage at the sensor
connector indicates that the wires from the sensor
connector to the ECM are not open or shorted to
ground.