Generac Power Systems GP Series Diagnostic Repair Manual page 13

Figure 2-18. Crankshaft Position Sensor
Figure 2-19. Crankshaft Position Sensor and
Flywheel
Engine Head Temperature Sensor
See Figure 2-20. The engine head temperature sensor
(EHT) is located on cylinder #1 and secured in place by a
bolt. The EHT monitors engine head temperature. This
data is sent to the ECM to assist in maintaining optimal
spark and fuel delivery while the unit is running.
Figure 2-20. Engine Head Temperature Sensor
Oxygen Sensor
See Figure 2-21. The oxygen sensor (OS), located on
the exhaust manifold, sends data to the ECM to assist in
maintaining optimal fuel delivery while the unit is running.
The OS is heated by voltage from the ECM for optimum
performance. The sensor sends a voltage signal
indicating the oxygen level in the exhaust. The ECM uses
that data to determine how much fuel to add for optimal
emissions and power.
Diagnostic Repair Manual
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Figure 2-21. Oxygen Sensor
Oil Pressure Switch
See Figure 2-22. The engine is equipped with a normally
open type, low oil pressure switch (OPS) (Item D) which
opens the circuit between the terminals when oil
pressure drops below a set threshold. The OPS is
connected to the ECM which will shutdown the engine
and activate the MIL on a low pressure signal.
015000
D
Figure 2-22. Low Oil Pressure Switch
Figure 2-23. Low Oil Pressure Switch
015001
CO Module
See Figure 2-24. The carbon monoxide (CO) module is
mounted near the generator control panel. It monitors
surrounding ambient air. If CO levels exceed a preset
threshold the CO module will send a signal to the ECM to
shut the engine down and activate the malfunction
indicator lamp (MIL).
Section 2 Electronic Engine Control
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009616
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