26 SEBU8121
Operation Section
Features and Controls
Coolant Temperature Sensor
The coolant temperature sensor monitors the engine
coolant temperature. The output of the ECM can
indicate a high coolant temperature through a relay
or a lamp. The coolant temperature sensor is used
by the ECM to determine initiation of the Cold Start
Condition and control for appropriate start of injection
timing while the engine is warming up.
Speed/Timing Sensor
If the ECM does not receive a signal from the primary
speed/timing sensor the “DIAGNOSTIC” lamp will
indicate a diagnostic fault code which will be logged
in the ECM memory.
If the ECM does not receive a signal from the primary
speed/timing sensor, the ECM will read the signal
from the secondary speed/timing sensor. The ECM
continually checks in order to determine if there is a
signal from both sensors. If either sensor fails, the
faulty sensor should be replaced.
Intermittent failure of the sensors will cause erratic
engine control.
Throttle Position Sensor
The throttle position sensor (TPS) eliminates the
mechanical throttle and governor linkages. The TPS
interprets the position of the throttle lever into an
electrical signal that is sent to the ECM. The throttle
position signal and the engine speed/timing signal
are processed by the ECM in order to precisely
control engine speed.
To Next Page
Loading...
