Main Monitors; Oxygen Sensor Monitor; Background - Mitsubishi Eclipse Technical Information Manual

MAIN MONITORS

To meet OBD II requirements, the on-board diagnos-
tic system must monitor the electrical input signals
and the performance of output responses that can
have an effect on vehicle emissions. In addition,
there are several "main monitors" that review the
result of system operations and their effect on emis-
sions. The main monitors are as follows:
Catalyst
l
Fuel System
l
Misfire
l
Exhaust Gas Recirculation
l
Secondary air (air injection)
l

Oxygen Sensor Monitor

Background

Effective control of exhaust emissions is achieved
by an oxygen feedback system. The most important
ENGINE <NON-TURBO> - Control Svstem
Each of the main monitors is listed below with a
brief background explanation and a description of
how the monitor operates. Following these condi-
tions is the diagnostic trouble code (DTC) this moni-
tor produces along with the DTC flashout number
and a number referred to as a SAE J 2012 or "P
code. SAE J 2012 codes required by law for use
with generic diagnostic scan tools.
element in this system is the oxygen (02) sensor
mounted in the exhaust manifold.