Chrysler 2000 LHS - Between 750 and 2000 RPM. Suppose the Sensors; Output Circuit Shorts to Ground When Engine Operates; Above 2400 RPM; PCM). Because the Condition Happens at an Engine

EMISSION CONTROL SYSTEMS
TABLE OF CONTENTS
page
ON-BOARD DIAGNOSTICS ................... 1
ON-BOARD DIAGNOSTICS
TABLE OF CONTENTS
page page
GENERAL INFORMATION
SYSTEM DESCRIPTION ....................1
DESCRIPTION AND OPERATION
MALFUNCTION INDICATOR LAMP (MIL)........2
DRB III STATE DISPLAY TEST MODE ..........2
DRB III CIRCUIT ACTUATION TEST MODE ......2
DIAGNOSTIC TROUBLE CODES ..............2
GENERAL INFORMATION
SYSTEM DESCRIPTION
The Powertrain Control Module (PCM) monitors
many different circuits in the fuel injection, ignition,
emission and engine systems. If the PCM senses a prob-
lem with a monitored circuit often enough to indicate an
actual problem, it stores a Diagnostic Trouble Code
(DTC) in the PCM’s memory. If the code applies to a
non-emissions related component or system, and the
problem is repaired or ceases to exist, the PCM cancels
the code after 40 warmup cycles. Diagnostic trouble
codes that affect vehicle emissions illuminate the Mal-
function Indicator Lamp (MIL). Refer to Malfunction
Indicator Lamp in this section.
Certain criteria must be met before the PCM
stores a DTC in memory. The criteria may be a spe-
cific range of engine RPM, engine temperature,
and/or input voltage to the PCM.
The PCM might not store a DTC for a monitored
circuit even though a malfunction has occurred. This
may happen because one of the DTC criteria for the
circuit has not been met. For example, assume the
diagnostic trouble code criteria requires the PCM to
monitor the circuit only when the engine operates
between 750 and 2000 RPM. Suppose the sensor’s
output circuit shorts to ground when engine operates
above 2400 RPM (resulting in 0 volt input to the
PCM). Because the condition happens at an engine
speed above the maximum threshold (2000 rpm), the
PCM will not store a DTC.
NOTE: Various diagnostic procedures may actually
cause a diagnostic monitor to set a DTC. For
instance, disconnecting the TP Sensor with the
ignition on may set the TP Sensor High code. When
a repair is completed and verified, use the DRB
scan tool to erase all DTC’s and extinguish the MIL.
Technicians can display stored DTC’s. Refer to
Diagnostic Trouble Codes in this section. For DTC
information, refer to charts in this section.
Fig. 1 Data Link (Diagnostic) Connector
LH EMISSION CONTROL SYSTEMS 25 - 1
2000 LHS, 300M, CONCORDE AND INTREPID