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I/M

Inspection and Maintenance

I/M Readiness

An indication of whether or not a vehicle's emissions-related system are operating properly and are ready for Inspection and Maintenance testing.

I/M Test / Emissions Test / Smog Check

A functional test of a vehicle to determine if tailpipe emissions are within Federal/State/Local requirements.

I/O

Input / Output

I/P

Instrument Panel

Intake Air

IAC

Idle Air Control (motor or solenoid)

IACV

Idle Air Control Valve

IAS

Inlet Air Solenoid valve or its circuit.

IAT

Intake air temperature sensor, performs same function as MAT sensor.

IBP

Integral Back Pressure

Ignition Control

Integrated Circuit

ICM

Integrated Control Module.

ICM

Ignition Control Module

ICP

Injection Control Pressure

ICS

Idle Control Solenoid (GM)

Inside Diameter

IDI

Integrated Direct Ignition

IDL

Idle Position Switch

Idle Speed Actuator

Extends or retracts to control engine idle speed and to set throttle stop angle during deceleration.

Idle Speed Control

Idle Speed Control, either computer control motor, air bypass valve, or any device used to control idle rpm.

IDLE SPEED STEPPER (ISS) MOTOR

The ISS motor (used on some Jeep engines) controls airflow inside the throttle body bypass passage to control idle speed. The ISS motor operates under control of the vehicle's on-board computer.

IDLE TRACKING SWITCH

An input device that sends a signal to the computer to indicate a closed throttle condition.

IDM

Ignition Diagnostic Monitor

IDM

Injector Driver Module

IFI

Indirect Fuel Injection

IFS

Inertia Fuel Switch

IGN

Ignition

IGN ADV

Ignition Advance

IGN GND

Ignition Ground

Ignition Diagnostic Monitor

Continuous monitor of ignition input to EEC-IV processor used to detect intermittent ignition faults.

ILC

Idle Load Compensator

IMA

Idle Mixture Adjuster

IMPEDANCE

The total opposition of a circuit to the flow of alternating current, measured in ohms (includes resistance and reactance).

IMRC

Intake Manifold Runner Control

IMS

Inferred Mileage Sensor (Ford)

IMS

Ignition Module Signal

IMT

Intake Manifold Timing

INDUCTION

The process of magnetizing and object, or of inducing a voltage in an object by placing it within a magnetic field.

INJ 1 to INJ 10

Fuel Injectors 1 to 10

INJECTOR

A fuel injection system electrical solenoid which, when energized, allows fuel flow into the intake manifold where it is mixed with air for combustion.

INPUTS

Information, in the form of a voltage or current, from a device external to the vehicle's on-board computer (switch, sensor, etc.) which assists the computer in monitoring and maintaining engine performance.

INSULATOR

Any material which will not conduct current. Insulators are commonly used to support or isolate conductors in an electrical/electronic circuit.

INT

Integrator (replaced with ST FUEL TRIM)

INTERMITTENT

Occuring infrequently (not continuously) and usually on an irregular basis. In electrical circuits, it refers to an occasional open, short, or ground.

INTERMITTENT FAULT

Fault which occurred during a previous engine operating cycle. Intermittent fault may have set a fault code which is still present in PCM memory.

IPC

Instrument Panel Cluster

IPR

Injector Pressure Regulator

IRCM

Integrated Relay Control Module, used on some Ford systems.

ISA

Idle Speed Actuator

ISC

Idle Speed Control

ISO

International Standard of Organization

ISS

Input Shaft Speed

ITA

Ignition Timing Adjustment

ITCS

Ignition Timing Control System (Honda)

ITS

Idle Tracking Switch

IVS

Idle Validation Switch

IVSC

Integrated Vehicle Speed Control

IVV

Idle Vacuum Valve (Ford)