TROUBLESHOOTING INTRODUCTION - CONTINUED
GENERAL INFORMATION - CONTINUED
Glossary - Continued
Cold Mode. Cold mode is a mode for cold starting and cold engine operation that includes retarded timing and raised
low idle. This mode is used for engine protection, reduced smoke emission, and faster warmup time.
Component Identifier (CID). CID is a number that identifies specific electronic control system component that has
experienced a diagnostic code.
Communication Adaptor Tool. Communication adapter provides a communication link between ECM and ET.
based devices. Also referred to as J1939 data link.
Coolant Level Sensor. Coolant level sensor detects absence or presence of coolant at probe. Sensor then sends a signal
Coolant Temperature Sensor. Coolant temperature sensor detects engine coolant temperature for cold mode operation
and engine monitoring.
Desired Engine Speed. Desired engine speed is input to electronic governor within ECM. Electronic governor uses sig-
nal from throttle position sensor, engine speed/timing sensor, and other sensors in order to determine desired engine
Diagnostic Code. A diagnostic code is sometimes referred to as a fault code. These codes indicate electronic system
Diagnostic Lamp. A diagnostic lamp is sometimes called "check engine light." Diagnostic lamp is used to warn opera-
tor of presence of an active diagnostic code.
Digital Sensors. Digital sensors produce a pulse width modulated (PWM) signal. Digital sensors are supplied with
+8 VDC from ECM.
Digital Sensor Return. Common line (group) from ECM is used as a ground for digital sensors.
Digital Sensor Supply. +8 VDC supply from ECM is used to power digital sensor.
Direct Current (dc). Direct current is a type of current that flows consistently in only one direction.
DT, DT Connector, or Deutsch DT. This is a type of connector used on CAT machines. Connectors are manufactured
Duty Cycle. Refer to "Pulse Width Modulation" in this glossary.
Electronic Control Module (ECM). ECM is an engine control computer. ECM provides power to electronics. ECM
monitors data input from engine sensors. ECM acts as a governor to control engine speed.
Electronic Engine Control (EEC). EEC is a complete electronic system. EEC monitors engine operation under all con-
ditions. EEC also controls engine operation under all conditions.
Electronic Technician (ET). ET is a service tool that uses a software program to run on an MSD to assist with trouble-
Engine Monitoring. Engine Monitoring is part of electronic engine control that monitors sensors and warns operator of
Engine Oil Pressure Sensor. Engine oil pressure sensor measures engine oil pressure. Sensor sends its signal to ECM.
Engine Speed/Timing Sensor. Engine speed/timing sensor provides a variable amplitude and PWM signal to ECM.
ECM interprets this signal as crankshaft position and engine speed.
Event Code. An event code may be activated to indicate an abnormal engine operating condition. These codes usually
indicate a mechanical problem instead of an electrical system problem.
Failure Mode Identifier (FMI). This identifier indicates type of failure experienced by components. FMI has been
adopted from SAE practice of J1587 diagnostics.