Example of Pulse Width Modulation SignalsRated Rack PositionA limit on rack position which provides the specified horsepower and torque curves. This value comes from maps programmed into the personality module at the factoryRack Position SensorA linear position sensor which follows movement of the rack assembly and sends an electrical signal to the ECM.Rack Solenoid (BTM)A rotary proportional solenoid (also called a BTM) used to move the fuel rack servo spool valve.Reference VoltageA regulated voltage supplied by the ECM to a sensor. The reference voltage is used by the sensor to generate a signal voltage.SensorA device used to detect and convert a change in pressure, temperature, or mechanical movement into an electrical signal.Service Program ModuleA software program on a factory programmable computer chip, designed to adapt an ECAP or DDT to a specific application.Short CircuitA condition where an electrical circuit is unintentionally connected to an undesirable point. Example: a wire which rubs against a vehicle frame until it wears off its insulation and makes electrical contact with the frame.SignalA voltage or waveform used to transmit information typically from a sensor to the ECM.Speed "burp"A sudden brief change in engine speed.Static Timing SpecificationFixed number of degrees determined by design of the fuel pump camshaft (determines injection timing with no advance). Note that the value displayed is the specification for static timing, not an electrically measured value.SubsystemAs used here, it is a part of the PEEC III System that relates to a particular function, for instance: throttle subsystem, etc.Supply VoltageA constant voltage supplied to a component to provide electrical power for its operation. It may be generated by the ECM, or it may be vehicle battery voltage supplied by the vehicle wiring."T" HarnessA test harness designed to permit normal circuit operation while measuring voltages, typically inserted between the two ends of a connector.Throttle PositionThe ECM's interpretation of the signal from the Throttle Position Sensor.Throttle Position SensorAn electronic sensor which is connected to the accelerator pedal and sends a Pulse Width Modulated signal to the ECM.Timing Position SensorA linear position sensor which follows movement of the timing advance unit and sends an electrical signal to the ECM.
