Technical information

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Technician Guidelines for Antilock Braking Systems

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Stopping Distance The distance required to stop a vehicle. Stopping distance

measurements begin when application (control) pressure first

begins to increase, and end when the vehicle comes to a com-

plete stop.

Tandem Control An ABS design in which the four wheels of the tandem axle are

controlled by only one modulator.

TMC The Maintenance Council of the American Trucking Associa-

tions. An industry group which develops voluntary recom-

mended practices on maintenance- and operation-related

issues pertaining to commercial vehicles, based on input from

equipment users, vehicle manufacturers, component suppliers,

academia, and government representatives.

TMC RP 137 TMC Recommended Practice 137 is a voluntary standard that

states tractors should deliver a minimum power level of 12.5

volts at 10 amps load to the trailer half of the tractor-to-trailer

electrical connector.

TMC RP 141 TMC Recommended Practice 141 is a voluntary standard that

states at least 9.5 volts (which includes a 1.0-volt safety margin)

must be available at the trailer ABS ECU to ensure proper

operation.

Tone Ring See Exciter.

Traction Control A system to minimize drive wheel slip (improve traction) under

acceleration. Traction control uses the ABS to apply braking

pressure to a spinning wheel, transferring engine power to the

wheel(s) with better traction. Should all the drive wheels start to

slip, traction control system can improve vehicle traction by

reducing engine torque. Traction control systems are referred

to by several different names, depending on the manufacturer.

These include:

• Automatic Traction Control (ATC)

• Traction Control (TC)

• Automatic Slip Regulation or Anti-Spin Regulation

(ASR)

Tooth Wheel See Exciter.