Throttle Position (TP) Sensor
- sends the ECM a signal indicating throttle plate angle
- is the main input to the ECM from the driver
- is mounted on the motor end of the throttle body
The throttle body also has an accelerator pedal position (APP) sensor consisting of twin potentiometers which provide separate analogue input signals, proportional to driver demand to the ECM. As a further safety feature the two potentiometers have different input/output characteristics for unique signal identifications and any corrupt signal between the expected outputs will cause the ECM to switch the throttle to limp home mode.