Engine Speed/Timing Sensor Circuit - Test - Perkins M190C 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 sensor is located on the left-hand side of
the cylinder block close to the flywheel housing. The
secondary speed/timing 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 timing ring. The timing ring is mounted
on the crankshaft. The signal that is generated by
the primary speed/timing sensor is transmitted to the
Electronic Control Module (ECM). The ECM uses the
signal from the sensor 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 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
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
i04010992
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.
KENR9126