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DESCRIPTION & OPERATION
Page 23
Engine Speed Sensor
This sensor is located at the left side of the
engine flywheel housing (Figure 17). It is flange-
mounted and held in place by a retaining screw.
The engine speed sensor is the same part
number as the engine position sensor,
located on the engine front cover.
17
Figure 17 — Engine Speed Sensor
The E-Tech™ flywheel has 117 teeth (one less
tooth than the E7 engine flywheel) and has two
adjacent teeth with part of their width (1/4 inch)
machined off. These two teeth on the E-Tech™
flywheel allow the sensor to determine top dead
center (TDC) of cylinder Nos. 1 and 6, whereas
sensing notches are used on the front face of the
E7 flywheel. Because of this feature, ring gear-to-
flywheel indexing must be maintained.
Engine Position Sensor
The engine position sensor is located on the
engine front cover (Figure 18) and is retained in
the same manner as the engine speed sensor.
This sensor is designed to monitor the passage of
holes which are in the front face of the camshaft
timing gear. This sensor performs a function
similar to the TEM sensor in the Bosch Injection
Pump RE30 governor on the E7 engine.
18
Figure 18 — Engine Position Sensor
Boost Temperature Sensor and Boost
Pressure Diagnostic Ports
A V-MAC III boost temperature sensor is located
on the top of the rear inlet manifold (Figure 19).
There is no boost pressure sensor because, as
with all V-MAC systems, V-MAC III uses ECU
programming for transient smoke control.
There are two boost pressure gauge ports just
forward of the boost temperature sensor. The
forward port is used for the dash boost pressure
gauge when chassis is so equipped. The port
adjacent to the boost temperature sensor can be
used to install a boost pressure gauge for
diagnostic purposes if the need arises.
19
Figure 19 — Boost Temperature Sensor and Boost
Pressure Gauge Ports
5_106_00.bk Page 23 Friday, August 4, 2000 11:17 AM
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