Description:
Sensors measure a variety of operating parameters that help to reduce emissions and
also serve functions for the engine, transmission and other
systems. These sensors generally include the manifold air temperature sensor, coolant temperature sensor, manifold absolute pressure sensor, airflow sensor, throttle position sensor, vehicle speed sensor and oxygen sensors.
Purpose: All of these sensors provide
critical operating information to the vehicle’s powertrain control
module, the onboard computer that compares the signals from the
sensors to programmed values.
Based on
the signals, the computer then issues commands to
various output devices to control the engine and transmission, along
with reducing emissions. 1996 and newer vehicles are equipped with second-generation
onboard diagnostics (OBDII) systems that put special emphasis on sensor values
and emissions.
Maintenance Tips/Suggestions:
Sensors do not require regular maintenance or adjustments. Regardless of what
a specific sensor measures, all operate within a range of normal
values. If a sensor provides a signal outside the normal range
long enough, the powertrain control module will
set a trouble code, which will usually trigger the SERVICE
ENGINE SOON or CHECK ENGINE light.
