Function of throttle position sensor
The throttle position sensor is installed on the throttle body (also known as the throttle valve body) and is linked to the throttle shaft, which is operated by the driver through the accelerator pedal. The function of the throttle position sensor is to convert the state of the throttle opening into an electrical signal and send it to the electronic control unit (ECU). The ECU uses the throttle opening size to obtain engine operating conditions (idle, partial load, full load, etc.) and the speed of throttle opening to obtain acceleration and deceleration information. The ECU uses this as a basis for judging different operating conditions of the engine, thereby determining the injection time of the fuel injector and the ignition advance angle. Therefore, the throttle position sensor (TPS) is a very important sensor in the engine centralized control system. It is the main signal source for idle control, starting and acceleration control, rapid acceleration and deceleration control, fuel cutoff control, ignition advance angle control, gasoline vapor recovery control, and automatic transmission shift control. Only by fully understanding the various characteristics of the throttle can we provide an important basis for ensuring the optimal driving condition of the car.
There are three types of sensors: switch-type, sliding resistance-type, and integrated-type.
(1) Maintenance of switch-type throttle position sensor
At the sensor socket, use a multimeter to measure the conductivity of the idle switch and full-load switch. When the throttle is fully closed, the idle switch should be conductive. When the throttle is fully open or nearly fully open, the full-load switch should be conductive; at other positions, neither of them should be conductive. Otherwise, it should be adjusted or replaced.
(2) Maintenance of sliding resistance throttle position sensor
When measuring with a multimeter at its socket, the resistance should increase linearly with the increase of throttle opening degree, and its maximum resistance value should also meet the specification, otherwise it should be replaced.
(3) Maintenance of integrated throttle position sensor
Using a multimeter to measure the resistance between the corresponding terminals on the socket of the integrated throttle position sensor with the throttle opening degree, the resistance should increase linearly with the increase of throttle opening degree. The maximum resistance value should also meet the specification, otherwise it should be replaced.
In addition, the resistance between the terminals on the socket corresponding to the idle switch should be adjustable according to the specified requirements, which is related to the gap between the throttle stop screw and the stop lever. If it cannot be adjusted as specified, the throttle position sensor should be replaced.
Figure Integrated Solar Position Sensor： 1 – resistance film; 2 – throttle opening output dynamic contact; 3 – idle dynamic contact VTA – throttle opening signal voltage terminal; IDL – idle signal voltage terminal; VC – power supply voltage signal terminal; E – ground terminal;
