Navistar International DT 466 Diagnostic/Troubleshooting Manual page 55

Crankshaft Position (CKP)
The CKP sensor provides the ECM with a signal
that indicates crankshaft speed and position. As the
crankshaft turns the CKP sensor detects a 60 tooth
timing disk on the crankshaft. Teeth 59 and 60 are
missing. By comparing the CKP signal with the CMP
signal, the ECM calculates engine rpm and timing
requirements. The CKP is installed in the top left side
of the flywheel housing.
NOTE: This long CKP
International® DT 466, DT 570, and HT 570
diesel engines, is the Camshaft Position (CMP)
sensor used with other International® diesel engines.
Camshaft Position (CMP)
The CMP sensor provides the ECM with a signal that
indicates camshaft position. As the cam rotates, the
sensor identifies the position of the cam by locating
a peg on the cam. The CMP is installed in the front
cover, above and to the right of the water pump pulley.
NOTE: This short CMP
International® DT 466, DT 570, and HT 570 diesel
engines, is the Crankshaft Position (CKP) sensor
used with other International® diesel engines.
Vehicle Speed Sensor (VSS)
The VSS provides the ECM with transmission tail shaft
speed by sensing the rotation of a 16 tooth gear on
the rear of the transmission. The detected sine wave
signal (AC), received by the ECM, is used with tire size
and axle ratio to calculate vehicle speed. The VSS is
on left side of the transmission.
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
1 ENGINE SYSTEMS
sensor, used with
sensor, used with
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
Figure 43 Potentiometer
1. Ground
2. Electronic Control Module (ECM)
3. Microprocessor
4. Voltage reference (V
5. Accelerator Position Sensor (APS)
Potentiometers
• APS
A potentiometer is a variable voltage divider that
senses the position of a mechanical component.
A reference voltage is applied to one end of the
potentiometer. Mechanical rotary or linear motion
moves the wiper along the resistance material,
changing voltage at each point along the resistive
material. Voltage is proportional to the amount of
mechanical movement.
Accelerator Position Sensor (APS)
The APS provides the ECM with a feedback signal
(linear analog voltage) that indicates the operator's
demand for power. The APS is mounted in the
accelerator pedal.
)
REF
51