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DS/VMV

Distributor spark/vacuum modulator valve.

DS/VRDV

Distributor spark/vacuum retard delay valve.

DS/VRV

Distributor spark/vacuum regulator valve.

DSAS

Deceleration spark advance system.

DSD

Acronym for Drivers Sliding Door.

DSDV

Distributor spark delay valve.

DSI

Distributor-less semiconductor ignition.

DSM

Acronym for 1. District Service Manager 2. Drivers Seat Module (GM).

DSO

An acronym for Digital Storage Oscilloscope.

Dsp

See digital signal processing.

DSR

Ford Diagnostic Subroutine (KOEF or KOER).

DTC

An acronym for diagnostic trouble code. It is also referred to as a fault code and is any code stored in the PCM memory.

DTCS

Distributor thermal control switch.

DTCV

Distributor thermal control valve.

DTM

Diagnostic test mode, or Deceleration throttle modulator.

DTVS

[1] Delay thermal vacuum switch [2] Dual Temperature Vacuum Switch.

DTVV

Delay thermal vacuum valve.

Dual Camshaft

A type of engine that has two camshafts for opening and closing additional valves.

Dual Exhaust

An exhaust system used on V-Type engines with a separate muffler, exhaust, and tail pipe for each cylinder bank.

Dual Exhaust

An exhaust system that features two pipes running to the rear of the vehicle. A "true" dual exhaust system will route exhaust from one side of a V6 or V8 engine to the rear of the vehicle through one pipe and route exhaust from the other side of the engine through another pipe. On any relatively new vehicle, a true dual exhaust system will feature at least two catalytic converters, as well as two mufflers and two tailpipes. Some other dual-exhaust setups feature one muffler with two entries and two exits.