Actron KAL9620A - Manual (Page 33)

9620 Professional OBD II Scan Tool 33
CKP REF:
Crankshaft Position Reference.
Closed Loop (CL):
A feedback system that uses the O2 Sensor(s) to monitor the results of combustion.
Based on the signal(s) from the O2 sensor(s), the PCM modifies the air/fuel mixture to
maintain optimum performance with lowest emissions. In closed loop mode, the PCM
can “fine tune” control of a system to achieve an exact result.
CO:
Carbon Monoxide
Continuous Memory Codes:
See Pending Codes.
CPS:
Crankshaft Position Sensor. Sends a frequency signal to the PCM. It is used to reference
fuel injector operation and synchronize spark plug firing on distributorless ignition
systems (DIS).
CTS:
Coolant Temperature Sensor. A resistance sensor that sends a voltage signal to the
PCM indicating the temperature of the coolant. This signal tells the PCM whether the
engine is “cold” or “warm”.
Data Link Connector (DLC):
Connector providing access and/or control of the vehicle information, operating
conditions, and diagnostic information. Vehicles with OBD II use a 16-pin connector
located in the passenger compartment.
Data Stream:
The actual data communications sent from the vehicle’s PCM to the data connector.
DEPS:
Digital Engine Position Sensor.
Detonation:
See Knock.
DTC:
Diagnostic Trouble Code. An alphanumeric identifier for a fault condition identified by
the On Board Diagnostic System.
DI/DIS:
Direct Ignition/Distributorless Ignition System. A system that produces the ignition spark
without the use of a distributor.
Duty Cycle:
A term applied to signals that switch between “on” and “off”. Duty cycle is the percentage of
time the signal is “on”. For example, if the signal is “on” only one fourth of the time, then the
duty cycle is 25%. The PCM uses duty cycle type signals to maintain precise control of an
actuator.
ECT:
Engine Coolant Temperature sensor. See CTS.
EFI:
Electronic Fuel Injection. Any system where a computer controls fuel delivery to the engine
by using fuel injectors.
EGR:
Exhaust Gas Recirculation. The PCM uses the EGR system to recirculate exhaust gases
back into the intake manifold to reduce emissions. EGR Recirculation is used only during
warm engine cruise conditions. EGR flow at other times can cause stalling or no starts.