Glossary
DUAL CATALYTIC CONVERTER – Combines 2 converters
in one shell. Controls NOx, HC and CO. Also called TWC.
DV TW – Delay Valve, 2 Way.
DVM (10 MEG) – Digital voltmeter with a minimum of 10
million ohms resistance. Allows measurement in circuit
without affecting the circuit operation.
DWELL – Amount of time (recorded on a dwell meter in
degrees) that current passes through a closed switch.
EAS – Electronic Air Switching, directs airflow to catalytic
converter or exhaust ports of the engine.
EBCM – Electronic Brake Control Module.
ECM – Engine Control Module properly call a Powertrain
Control Module.
ECT – Engine Coolant Temperature sensor or circuit.
ECU – Electronic Control Unit. To process input information
to trigger ignition control module.
EDF – Electro-Drive Fan relay or its circuit.
EECS – Evaporative Emission Control System.
EEGR – Electronic Exhaust Gas Recirculation valve (Sonic).
EEPROM – Electronically Erasable Programmable Read Only
Memory.
EET – Electronic Exhaust Gas Recirculation Transducer.
EFC – Electronic Feedback Carburetor. Utilizes an electronic
signal, generated by an exhaust gas oxygen sensor to precisely
control air/fuel mixture ratio in the carburetor.
EFI – Electronic Fuel Injection. Computer controlled fuel
injection system.
EGO – Exhaust Gas Oxygen sensor.
EGR – Exhaust Gas Recirculation system is designed to allow
flow of inert exhaust gases into combustion chamber to cool
combustion and reduce nitrous oxides in exhaust.
EHC – Exhaust Heat Control vacuum solenoid or its circuit.
EHCU - Electro-Hydraulic Control Unit.
EIC – Electronic Instrument Cluster.
ELECTRONIC SPARK CONTROL – Used to retard spark
advance if detonation occurs.
ELECTRONIC SPARK TIMING – PCM controlled timing of
the ignition spark.
EMI - Electro-Magnetic Interference.
GM
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