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CHECK VALVE – Valve that operates like a one-way gate.
CID – Cylinder Identification sensor or its circuit.
CKT – Circuit.
CL – Closed Loop.
CLC – Converter Lock-up Clutch.
CO – Carbon Monoxide.
COC – Conventional Oxidation Catalyst.
COMPUTER TIMING –Total spark advance in degrees
before top dead center.
CPS – Crankshaft Position Sensor. Provides the ECU with
engine speed and crankshaft angle (position).
CRT – Cathode Ray Tube. A device for displaying video
signals, similar to a television picture tube. Similar devices
used on General Motors vehicles are referred to as DID or VIC.
CTS – Coolant Temperature Sensor.
CURB IDLE – Computer controlled idle rpm.
CVR – Control Vacuum Regulator.
CWM – Cold Weather Modulator.
CYLINDER IDENTIFICATION SIGNAL (CID) – A signal
generated by crankshaft timing sensor, used to synchronize
ignition coils, due to the fact that some models use a 2 ignition
coil pack DIS system.
C 3 I – Computer Controlled Coil Ignition. Produces ignition
spark without aid of an ignition distributor.
DCL – Data Communications Link.
DERM – Diagnostic Energy Reserve Module and air bag (SIR)
controller.
DFS – Decel Fuel Shut-off.
DIC – Driver Information Center.
DID – Driver Information Display.
DIS – Direct Ignition System. Produces ignition spark without
aid of an ignition distributor. (Similar to C 3 I).
DLC – Data Link Connector.
DRA – Digital Ratio Adapter.
DRAB – Digital Ratio Adapter Buffer.
DRAC – Digital Ratio Adapter Calibrator.
DTC – Diagnostic Trouble Code.
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GM