Throttle Position Sensor
Throttle Position (TP) sensor is mounted on throttle body and monitors opening angle of throttle valve. See Figure -Figure , Fig 1 and Fig 2 . The TP sensor is a 3-wire variable resistor that provides the Powertrain Control Module (PCM) with an input signal (voltage) that represents the throttle blade position of the throttle body. The sensor is connected to the throttle blade shaft. As the position of the throttle blade changes, the resistance (output voltage) of the TP sensor changes. The PCM supplies approximately 5 volts to the TP sensor. The TP sensor output voltage (input signal to the PCM) represents the throttle blade position. The PCM receives an input signal voltage from the TP sensor. This will vary in an approximate range from .26 volt at minimum throttle opening (idle) to 4.49 volts at wide open throttle. Along with inputs from other sensors, the PCM uses the TP sensor input to determine current engine operating conditions. In response to engine operating conditions, the PCM will adjust fuel injector pulse width and ignition timing. The PCM needs to identify the actions and position of the throttle blade at all times. This information is needed to assist in performing the following calculations.
- Ignition Timing Advance
- Fuel Injection Pulse Width
- Idle (Learned Value Or Minimum TPS)
- Off-Idle (0.06 Volt)
- Wide Open Throttle (WOT) Open Loop (2.608 Volts Above Learned Idle Voltage)
- Deceleration Fuel Lean Out
- Fuel Cutoff During Cranking At WOT (2.608 Volts Above Learned Idle Voltage)
- A/C WOT Cutoff (Certain Automatic Transmissions Only)