Engine Speed/Timing Sensor Circuit - Test - Perkins NJ Series Troubleshooting Manual

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Troubleshooting Section
Engine Speed/Timing Sensor
Circuit - Test
System Operation Description:
Use this procedure to troubleshoot the system under
the following conditions:
• Use this procedure if another procedure has
directed you here.
• The engine will not start and the electronic service
tool indicates a faulty sensor by displaying "Not
Detected" against the faulty sensor on the "No
Start Parameter" screen.
• There is an active diagnostic code or a recently
logged diagnostic code that is related to the
following:
•
0190-08 Engine Speed Sensor abnormal
frequency, pulse width, or period
• 0342-08 Secondary Engine Speed Sensor
abnormal frequency, pulse width, or period
The engine uses two engine speed/timing sensors.
The primary crankshaft speed/timing sensor is
located on the left hand side of the cylinder block
close to the flywheel housing. The secondary
camshaft/fuel rail pump sensor is mounted on the fuel
rail pump. The primary speed/timing sensor that is
mounted on the cylinder block generates a signal by
detecting the movement of the teeth that are located
on the speed/timing wheel. The speed/timing wheel
is connected to the crankshaft. The signal that is
generated by the speed/timing sensor is transmitted
to the Electronic Control Module (ECM). The ECM
uses the speed/timing sensor signal to calculate the
position of the crankshaft. The signal is also used to
determine the engine speed.
The secondary speed/timing sensor is located in
the fuel rail pump. The secondary speed/timing
sensor generates a signal that is related to the
camshaft position. The fuel rail pump is mechanically
connected to the camshaft. The secondary
speed/timing sensor detects the movement of
the teeth on the speed/timing wheel in the fuel
rail pump. The signal that is generated by the
speed/timing sensor is transmitted to the ECM. The
ECM calculates the speed and the rotational position
of the engine by using the signal. The secondary
speed/timing sensor is required for starting purposes.
During normal operation, the secondary speed/timing
i02491413
sensor is used to determine the cycle that the
engine is on. When the timing has been established,
the primary speed/timing sensor is then used to
determine the engine speed and the angular position.
The loss of signal to the primary sensor and/or the
secondary sensor will result in one of the following
faults:
•
The loss of signal from the secondary speed/timing
sensor during start-up will prevent the engine from
starting.
• The engine will continue to run when only one
sensor signal is present from either the primary
sensor or the secondary sensor.
• The loss of signal from the primary speed/timing
sensor during operation of the engine will result in
engine operation with a derate.
• Loss of signal from the primary sensor and the
secondary sensor during operation of the engine
will cause fuel injection to be terminated and the
engine will stop.
The primary sensor and the secondary sensor are
interchangeable components. If a sensor is suspect
the sensors can be exchanged in order to eliminate
a fault. If a secondary sensor is suspect and a
replacement secondary sensor is not available, then
the primary sensor and the secondary sensor can be
exchanged. This will allow testing to determine if the
secondary sensor is faulty.
SENR9982-01