Acronyms and Definitions: Transmissions

WARNING: This page does not describe the selected car, but rather 30 other vehicles, including the 2004 Mercury Sable, 2004 Mercury Mountaineer, 2004 Mercury Monterey, 2004 Mercury Marauder, and 2004 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: The transmission naming convention is as follows:

The first character, a number, is the number of forward gears.
The second character, either the letter "F" or "R," represents front (transaxle) or rear (transmission) wheel drive.
The next set of characters, a grouping of numbers, represents the design torque capacity of the transmission/transaxle (for example, "27" represents 270ft./lbs. in the 4F27E transaxle).
The last character, if used, is one of the following:
- "E" for electronic shift
- "N" for non-synchronous shift
- "S" for synchronous shift
- "W" for wide ratio

4F27E : Also known as the FN Focus automatic transmission.

4F44E : Formerly known as the CD4E.

4F46S : Formerly known as the AX4S and regular-duty AXOD-E.

4F50N : Formerly known as the AX4N and heavy-duty AXOD-E.

4R44E : Formerly known as A4LD for 3.0L applications.

4R55E : Formerly known as A4LD for 4.0L applications.

4R70W : Formerly known as AOD-E.

4R100 : Formerly known as E4OD.

5R44E : Formerly known as A5LD for 3.0L applications.

5R55E : Formerly known as A5LD for 4.0L applications.

5R55N : Lincoln LS automatic transmission.

5R55W : Wide-ratio truck transmission.

4x4L : 4x4 Low.

A/T : Automatic Transmission.

CCS : Coast Clutch Solenoid.

CCSF : Coast Clutch Solenoid Fault. Displays a YES if fault exists.

EPC, EPC1, EPC2 : Electronic Pressure Control.

EPCV : Electronic Pressure Control Volts.

ESS : Electronic Shift Scheduling.

HCDSS : High Clutch Drum Speed Sensor. PCM input from the 4R44E and 4R55E.

ISS : Intermediate/Input Shaft Speed Sensor.

M5OD : Manual 5-Speed transmission with overdrive (RWD).

M/T : Manual Transmission/Transaxle.

NPS : Neutral Pressure Switch or its signal input to the PCM.

OCS : Overdrive Cancel Switch.

OSS : Output Shaft Speed. Indicates rotational speed of the transmission output shaft.

PNP : Park/Neutral Position switch. Also known as Neutral Drive Switch (NDS), Neutral Gear Switch (NGS), and Transmission Switch Neutral (TSN).

REVERSE or REV : Transmission Reverse Switch Input.

SIL : Shift Indicator Lamp. A lamp that indicates the preferred shift points on select manual transmission/transaxle vehicles.

SS1/SS2/SS3 : Shift solenoids. Devices that control the shifting in an automatic transmission.

TCC/TCCH : Torque Converter Clutch. When energized, causes a mechanical engagement and disengagement of the Torque Converter Clutch.

TCIL : Transmission Control Indicator Lamp. Indicates that the TCS has been activated.

TCS : Transmission Control Switch. Modifies the operation of electronically controlled transmissions.

Torque converter : A device which by its design multiplies the torque in a fluid coupling between an engine and transmission/transaxle.

TFT : Transmission Fluid Temperature. Indicates temperature of transmission fluid.

Transaxle : A device consisting of a transmission and axle drive gears assembled in the same case. Front-wheel drive applications.

Transmission : A device which selectively increases or decreases the ratio of relative rotation between its input and output shafts. Rear-wheel drive applications.

TR, TR1, TR2, TR3, TR4 : Transmission Range. The range in which the transmission is operating.

TR Sensor : Formerly known as Manual Lever Position Sensor (MLPS). Provides information to the PCM on the transmission range selector position.

TR V : Transmission Range Voltage.

TSS : Turbine Shaft Speed. Indicates rotational speed of the transmission turbine shaft.

VSS : Vehicle Speed Sensor. A magnetic pickup device that generates an AC signal that is proportional to vehicle speed.