What does it mean?
The throttle position sensor (TPS) is located on the throttle body. It is a type of variable resistor which changes its resistance value according to throttle position. As the throttle is opened, the voltage reading goes up. This information is used by the PCM to determine output controls such as fuel injection and idle air control. Most throttle position sensors are simple and easy to troubleshoot. There are three wires attached to the TPS: power, ground and signal.
Power, or reference voltage, goes into the TPS. The sensor then sends a return signal voltage to the PCM. The return voltage depends on throttle positon. Typically, the signal value at idle will be about .45 volts. This voltage reading increases as the throttle is opened and will read about 4.5 volts at wide open throttle (WOT). Many late model vehicles don’t use a throttle wire. Instead, they use what is referred to as “drive by wire”.
In these systems, a motor is used to operate the throttle using inputs from position sensors on the accelerator pedal. When the gas pedal is depressed, the control module commands the throttle to open. Then, a pair of TPS sensors relay the throttle positon to the control module so it knows everything is working properly.
A typical throttle position sensor Note: Circuit Low Input codes are often the result of low battery voltages (that can have many possible causes), bad connections across electrical connectors or previously repaired wiring, as well as corrosion in electrical connectors.
Other possible causes of low input voltages include poor installation of aftermarket components, poor quality aftermarket components like fuses, relays, and switches, and modification of the electrical system that could include the use of conductors that are not rated for use in a particular application. However, poor connections often result in high resistances in some parts of the circuit, which is why it is important to perform resistance and continuity checks during the diagnostic procedure.