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DFI

Digital fuel injection.

DFRDTE

(Porsch) Oxygen sensor Difference.

DFS

Dual function switch or deceleration fuel shutoff.

DG

An acronym for double-groove valve tem.

DI

Distributor ignition or direct ignition.

Dia

An abbreviation for diameter.

Diac

A bidirectritional diode.

Diagnose

To recognize by signs and symptoms.

Diagnosis

1. A standard procedure that is followed to locate and identify the cause of a malfunction. 2. The art or act of identifying the cause of a problem or malfunction by observing its signs and symptoms.

Diagnostic

Any number of on-board tests run by the diagnostic management system which checks for malfunctions, errors or breakdowns in vehicle systems or components.

Diagnostic Code

A set of Numbers obtained from a Computer either by the use of flashing "Check Engine" lights or with the use of a scan tool.

Diagnostic Executive

The diagnostic management system software that stores testing results and controls the illumination of the malfunction indicator lamp.

Diagnostic Management System

The PCM system responsible for performing testing of the power train components and systems, recording testing results and performing test fail actions.

Diagnostic Mode

This Chrysler mode of operation is used by the Logic Module to indicate malfunctions to the technician through Flash codes.

Diagnostic Read Out BOX

Chrysler's Scan tool now up to DBR IV.

Diagnostic Trouble Code

A number generated by the vehicles computer to indicate a failure in a sensor, circuit, or the computer itself.

Diagnostic Trouble Codes

Any code stored in a control module memory used to aid the technician in the diagnosis of a system.

Diagnostician

A person who determines the cause of problems when given all the signs and symptoms.

Diagonal Brake System

A dual-brake system with separate hydraulic circuits connecting diagonal wheels together; right front to left rear and left front to right rear.

Diagonal Cross Check

In preparation for oval-track racing, the measure of weight distribution between the right-front and left-rear wheels and between the left-front and right-rear wheels.