C

CALIFORNIA AIR RESOURCES BOARD (CARB) - Policy-making arm of the California legislature concerned with air and environmental issues.

CANISTER - A container, in an evaporative emission control system, that contains charcoal to trap vapors from the fuel system.

Canister Purge Valve:

CANISTER PURGE VALVE - Valve used to regulate the flow of vapor from the charcoal canister to the engine.
CANISTER PURGE SHUT OFF VALVE - A vacuum operated valve which shuts off canister purge when this thermactor air diverted valve dumps air downstream.

Canister Purge Solenoid:

CANISTER PURGE SOLENOID (CANP) - Electrical solenoid or its control line. Solenoid opens valve from fuel vapor canister line to intake manifold when energized. Controls flow of vapors between carburetor bowl vent and carbon canister.
CARBON MONOXIDE - A colorless, odorless, poisonous gas, composed of carbon and oxygen, that is a component of auto exhaust emissions. Abbreviation is CO.

CAS - Cleaner Air System.

CATALYST - A compound or substance which can speed up or slow down the reaction of other substances without being consumed itself. In an automatic catalytic converter special metals (i.e., platinum, palladium) are used to promote more complete combustion of unburned hydrocarbons and a reduction of carbon monoxide.

CATALYTIC CONVERTER (CC) - A mufflerlike component in the exhaust system that promotes a chemical reaction that converts certain air pollutants in the exhaust gases into harmless substances.

CHECK ENGINE LIGHT (CEL) - A dash panel light used either to aid in the identification and diagnosis of the EEC system problems or to indicate that maintenance is required on non-EEC equipped vehicles.
CHECK VALVE - A one-way valve which allows a liquid or gas to flow in one direction only - prevents backflow.


CLOSED LOOP MODE - Mode in which the ECA operates with EGO sensor feedback.

Closed Crankcase Emission System:

CLOSED SYSTEM - Crankcase ventilation system which vents crankcase pressure and vapors back into the engine where it is burned during combustion rather than venting to the atmosphere.
CLOSED THROTTLE MODE - Mode in which the ECA varies the pulses width input of the fuel injectors and obtains the desired air/fuel mixture. Many input sensors are used by the ECA in this mode.


COASTING RICHER SOLENOID VALVE (Courier) - Adds additional fuel to a lean mixture caused by deceleration. Controlled by accelerator and speedometer switch.


COLD START SPARK ADVANCE SYSTEM (CSSA) - Added to the distributor spark control on some engines. System momentarily traps spark port vacuum on the distributor spark advance diaphragm when engine coolant temperature is below 53~C (128~F). Used in conjunction with a DRCV and a CSSA PVS.
COLD START SPARK HOLD SYSTEM (CSSH) - Provides improved cold engine acceleration. When engine coolant is less than 53~C (128~F) the CSSH PVS is closed and the distributor vacuum signal travels through a restrictor providing a modified vacuum advance during the initial stage of acceleration.


COLD TEMPERATURE ACTUATED VACUUM SWITCH (CTAV) - Used with MCU system to signal open loop or closed loop operating modes.

Cold Weather Modulator:

COLD WEATHER MODULATOR (CWM) - A vacuum modulator located in the carburetor air cleaner on some models. Prevents the air cleaner duct door from opening to non-heated intake air when fresh air is below 13~C (55~F). Looks like a Temperature Vacuum Switch, differentiated by color codes.
COMBINATION THERMACTOR AIR BYPASS AND AIR DIVERTER VALVE - Combines the function of a normally closed air bypass valve and an air control valve in one integral valve.


COMPUTED TIMING - The relationship of spark plug firing to crankshaft position expressed in crankshaft degrees. On EEC-II and III crankshaft position was determined by the crankshaft position (CP sensor). On EEC-IV this function is controlled by the Profile Ignition Pickup (PIP) sensor.
CONTINUOUS CODES - Service codes stored in the processor's Keep Alive Memory (KAM) as a result of a failure (open or short), either intermittent or constant, detected in one of the sensor circuits (i.e., sensor-harness-processor). Codes are output only during Key On/Engine Off test.


CONTINUOUS MONITOR - An aid in diagnosing intermittent failures in the sensor input circuits. Monitor is activated in either Key On/Engine Off or engine running modes.


CONTROL VALVE (CV) - A valve whose operation directs the operation of other components.


CONVENTIONAL OXIDATION CATALYST (COC) - Catalyst which acts on the two major pollutants: HC and CO.


CONVERTER - Applied to liquefied petroleum gas: a device which converts or changes LP-Gas from liquid to vapor for use in engine.


COOLANT SPARK CONTROL (CSC) - A spark control system which is affected by coolant temperature, monitored by a sensor which provides input to the processor.


COOLANT TEMPERATURE OVERRIDE (CTO) - Occurrence where normal electronic component operation is stopped or delayed because of a change in coolant temperature.


CRANKCASE BREATHER - A port or tube that vents fumes from the crankcase. An inlet breather allows fresh air into the crankcase.

CRANKING RETARD MODULE - Ignition module which features a circuit that retards the ignition timing up to 18 degrees.

CRANKING SIGNAL (CRK) - Battery voltage that is switched to ECA by ignition switch during cranking (start) only.

Crankshaft Position Sensor:

CRANKSHAFT POSITION SENSOR (CP) - Permanent magnet with coil. Sensor produces AC pulse when magnetic pulse sensor is disrupted by a gear tooth or notch. Senses pulse ring lobes. Resultant signal enables ECA to determine when the ignition module should be triggered to produce a spark. Also, provides RPM information which is used to calculate spark advance, EGR flow and air/fuel ratio (replaces distributor centrifugal advance weights and timing pickup). One pulse is produced for each cylinder every other engine rotation (one for each spark plug firing). Example: 4 pulses are produced for each V8 engine rotation. The CP pulse is generated at 10 Before Top Dead Center (BTDC).


CP (+) - Crankshaft Position Sensor (CP) Signal Line.


CP (-) - Crankshaft Position Sensor (CP) Return Line. Connects to ground in ECA.