The electronic control unit, also called the ECU, is the brain of the automobile. This small device is typically located behind the glove compartment, underneath the vehicle's dashboard. Modern automobile design utilizes many electric components that determine fuel delivery, transmission shift points and ignition timing, to name only a few. These components take direction from the electronic control unit, which controls all electronic functions within the vehicle's drive train.
Actually a small computer,
the electronic control unit takes readings from all of the vehicle's
electronic sensors and interprets the vehicle's needs. In order to
operate at the peak fuel mileage and performance, the electronic control
unit makes continual adjustments to the engine's fuel delivery circuits
as well as the ignition timing to provide the proper air and fuel
mixture being ignited at the optimal time in the combustion chamber. This ensures the vehicle is operating at the utmost peak power and economy level possible.
Important on-the-fly adjustments are not limited to the vehicle's engine by the electronic control unit. The transmission's torque converter, in an automatic transmission-equipped
vehicle, is locked and unlocked according to information received by
the electronic control unit. By locking the torque converter, the
electronic control unit is able to eliminate fuel-wasting transmission slippage,
which equates to higher fuel costs for the owner. The electronic
control unit also determines the optimal shift points for the
transmission based on feedback received from the engine, which takes
advantage of the peak horsepower and torque produced by the engine.
Many of the vehicle's components and engine
systems can be monitored by the control unit. The oil condition as well
as maintenance schedules are monitored by the unit. By taking readings
from sensors within the engine, the unit is able to decipher the proper
intervals for scheduled maintenance. When a problem within the drive
train is detected, the unit sends a message to the operator via a
message board in the instrument cluster.
The electronic control unit provides the proper
application of fuel in cold climates to ensure a smooth cold weather
start. Trouble-free operation in any weather condition is provided
through the system's monitoring of the control unit. Often making
adjustments many thousands of times per minute, the control unit is like
having a personal mechanic riding along to keep things running
smoothly. When there is a problem with any part in the vehicle's
electronic system, the control unit is able to flash a code directing
the service attention to the correct area.