Chrysler 2004 Concorde Service Manual page 1613

LH
EMISSIONS CONTROL
DESCRIPTION
DESCRIPTION - MONITORED COMPONENT
DESCRIPTION - VEHICLE EMISSION
CONTROL INFORMATION LABEL . . . . . . . . . . 5
DESCRIPTION - TRIP DEFINITION
OPERATION - NON-MONITORED CIRCUITS
DESCRIPTION - MONITORED SYSTEMS
EMISSIONS CONTROL
DESCRIPTION
DESCRIPTION - MONITORED COMPONENT
There are several components that will affect vehi-
cle emissions if they malfunction. If one of these com-
ponents malfunctions the Malfunction Indicator
Lamp (Check Engine) will illuminate.
Some of the component monitors are checking for
proper operation of the part. Electrically operated
components now have input (rationality) and output
(functionality) checks as well as continuity tests
(opens/shorts). Previously, a component like the
Throttle Position sensor (TPS) was checked by the
PCM for an open or shorted circuit. If one of these
conditions occurred, a DTC was set. Now there is a
check to ensure that the component is working. This
is done by watching for a TPS indication of a greater
or lesser throttle opening than MAP and engine rpm
indicate. In the case of the TPS, if engine vacuum is
high and engine rpm is 1600 or greater and the TPS
indicates a large throttle opening, a DTC will be set.
The same applies to low vacuum and 1600 rpm.
Any component that has an associated limp in will
set a fault after 1 trip with the malfunction present.
Refer to the Diagnostic Trouble Codes Description
Charts in this section and the appropriate Power-
train Diagnostic Procedure Manual for diagnostic
procedures.
The following is a list of the monitored compo-
nents:
• Catalyst Monitor
• Comprehensive Components
• EGR (if equipped)
• Fuel Control (rich/lean)
• Oxygen Sensor Monitor
• Oxygen Sensor Heater Monitor
EMISSIONS CONTROL
TABLE OF CONTENTS
page
OPERATION
. 1
EVAPORATIVE EMISSIONS
. . . . . . . . . 5 EXHAUST GAS RECIRCULATION
. . 5 ON-BOARD DIAGNOSTICS
. . . . 6
COMPREHENSIVE COMPONENTS
that the diagnostic system monitor any component
that could affect emissions levels. In many cases,
these components were being tested under OBD I.
The OBD I requirements focused mainly on testing
emissions-related components for electrical opens and
shorts.
powertrain components to the PCM be tested for
rationality, and that outputs to powertrain compo-
nents from the PCM be tested for functionality.
Methods for monitoring the various Comprehensive
Component monitoring include:
NOTE: Comprehensive component monitors are
continuous. Therefore, enabling conditions do not
apply. All will set a DTC and illuminate the MIL in 1-
trip.
PCM are constantly being monitored for electrical
opens and shorts, they are also tested for rationality.
This means that the input signal is compared against
other inputs and information to see if it makes sense
under the current conditions.
EMISSIONS CONTROL 25 - 1
DESCRIPTION - HIGH AND LOW LIMITS
OPERATION - SYSTEM
DRB III STATE DISPLAY TEST MODE
• Purge
• Misfire
• Natural Vacuum Leak Detection (NVLD)
Along with the major monitors, OBD II requires
However, OBD II also requires that inputs from
(1) Circuit Continuity
• Open
• Shorted high
• Shorted to ground
(2) Rationality or Proper Functioning
• Inputs tested for rationality
• Outputs tested for functionality
Input Rationality—While input signals to the
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