T

TERMINAL - A device attached to the end of a wire or cable to make an electrical connection.

THERMISTOR - A resistor that changes its resistance with temperature.

THERMOCOUPLE - A thermoelectric device used to measure temperature accurately, especially one consisting of two dissimilar metals joined together so that a potential difference is generated between the points of contact. The amount of potential difference is a measure of the heat at the point of contact of the two dissimilar metals.


THICK FILM IGNITION (TFI) -IV - Electronic ignition system utilizing a Hall-Effect sensor to switch the ignition coil on and off through the ECA. The term "thick film" is Lised to describe the process used to build the TFI circuit on the module. The basic circuit is placed on a layer of alumina. Several layers of film are required to print the circuit - hence the name "thick film." The resistors and connecting paths are part of the film. Other components such as capacitors, diodes, darlington transistors and integrated circuits are added on top of the thick film or are attached to it. There are two TFI systems, TFI-I used on 1982 1.6L engines, and TFI-II used on engines after 1983 with EEC-IV. The TFI-IV ignition system uses no vacuum or centrifugal advance, all advance is controlled by the ECA. TFII utilizes vacuum and centrifugal advance. Both TFI-I and IV use an E-core coil instead of an oil filled coil.

THICK FILM IGNITION (TFI) MODULE - Smaller module which is mounted on the distributor and fires the ignition coil.

THROUGHPUT - The flow of a voltage signal from input to output.

TIMER - A feature of microcomputers which allows the microcomputer to measure time intervals, such as "time since engine start" or "time in neutral idle."
TRANSDUCER - A device that changes energy from one form to another. For example, a transducer is used to change the pulse of fuel injection in a diesel to electricity so that timing can be checked. In automotive air-conditioning controls used in automatic temperature systems, a transducer changes an electrical signal to a vacuum signal, which operates mechanical doors.

TRANSFER HOSE - Hose on the speed control servo that connects either manifold vacuum or atmospheric pressure to the sealed side of the diaphragm, depending on servo solenoid positions.

TRANSISTOR - A small solid-state electronic switching device which uses semiconductors. Widely used to replace vacuum tubes and switches.

TRUTH TABLE - A chart that lists all of the possible combinations of inputs and the corresponding outputs for a logic gate.