Edelbrock 3670 User Manual - page 227

Appendices

227

ECU

Engine Control Unit: The electronic “box” that controls the

engine functions. Sometimes referred to as the PCM (Power

train Control Module) or ECS (Engine Control System). Various

manufacturers have a variety of acronyms for the controller.

The Pro-Tuner refers to the ECU specifically as "ECM" for the

48 pin ECU and "PCM" for the 80 pin ECU.

Equivalence Ratio

Actual air/fuel ratio divided by the air/fuel ratio at

stoichiometry.

Example: 1.0 would be stoichiometric for the fuel being used

(~14.7:1 for gasoline). 1.1 would represent 10% Richer, and

0.90 would represent 10% Leaner than stoichiometric.

This is the inverse of Lambda.

Even Row Highlight

Feature in the Maps to turn on and off the alternating gray and

white rows. This feature makes cell location easier to

determine.

F

Fault Code

The ECU continually monitors sensors and actuators for

possible faults. If you click on the "FAULT" light in the bottom

status bar, a list of fault codes and reasons will be listed.

Fault Code (Active)

A fault code that is currently being detected by the ECU. Once

a fault becomes active, it will also be triggered as "Occurred".

Fault Code

(Occurred)

A fault code that has occurred since the last time the ignition

key was turned on. It may not be currently Active and may

have been a momentary fault.

Fault Code

(Suspected)

A fault code that is "possible" and may become active. The

ECU has detected some intermittent conditions that may be

diagnosed as a marginal or failing component.

Feedback AFR/EqR

Air Fuel Ratio (or Equivalency Ratio) as calculated from

readings from the O2 sensor

Flight Recorder

Capability that allows for recording chosen parameters for later

review. This differs from Data Logging by the fact that the

parameters are saved physically in the ECU, thus allowing

recording even without a PC or laptop connected.

Forced Induction

An engine that uses a device to force additional air into the

cylinders, such as a turbocharger or supercharger.

G

Gain

The ratio of a system's output magnitude to its input

magnitude.

Gain (Differential)

This controls the dampening affect of a system. Example:

Increasing the Differential gain for an IAC will control how

much the IAC anticipates a change and how fast it reacts to an

input. The D term deals with the "rate of change" of the

parameter. The faster the parameter is nearing or going away

from set point - the D term output will increase.