How to check the quality of electronic throttle?
Audi 200 throttle position sensor harness connector * * * has three terminals. The middle terminal is a power supply terminal, and one of the terminals on both sides is an idle switch signal terminal; The other is the signal terminal of the heavy-duty switch.
Detection method:
① Turn on the ignition switch, and use the multimeter voltage block to check the voltage on the power terminal of the connector at the harness side, which should be the battery voltage.
② Turn off the ignition switch, unplug the throttle harness connector, and check the continuity between related terminals with a multimeter.
When the no-load switch is closed, that is, when the no-load contact is turned on, the signal terminal and the intermediate terminal of the no-load switch should be connected; When the no-load switch is turned on, that is, when the no-load contact is turned off, the signal terminal of the no-load switch should be connected with the intermediate terminal; When the throttle opening is less than 57, the heavy-duty switch is turned on, that is, when the contact of the heavy-duty switch is turned off, there should be no conduction between the signal end and the intermediate end of the heavy-duty switch; When the throttle opening is greater than 57, the heavy-duty switch is closed, that is, when the contact of the heavy-duty switch is turned on, the signal end and the intermediate end of the heavy-duty switch should be turned on.
If the inspection does not conform to the above rules, the throttle position sensor is faulty and should be repaired or replaced.
2 Linear Variable Resistance Throttle Position Sensor
The detection method of throttle position sensor of Shanghai GM Regal 2.0L car is as follows:
When the throttle is closed, the output voltage is low, and when the throttle is fully opened, the output voltage is greater than 4.0V The electronic control unit calculates fuel supply, ignition timing, idle speed, exhaust gas recirculation, fuel evaporative emission control and air conditioning cut-off control according to the throttle opening signal. The connector terminal of the sensor and its connection circuit are shown in the following figure.
The detection method is as follows:
① Check the power supply voltage. Turn on the ignition switch and measure the voltage between terminal A and ground, which should be 5V.
② Check the continuity of the sensor. Check the sensor terminal B and ground, they should be conductive. If the test result does not meet the requirements, replace the throttle position sensor.
3 Integrated throttle position sensor
The comprehensive throttle position sensor is formed by setting engine idle contact on the basis of linear variable resistance throttle position sensor.
Taking Toyota Crown 3.0 car as an example, the detection method of comprehensive throttle position sensor is explained. The connection circuit with ECU is shown in the following figure.
① Detection of sensor resistance
Remove the connector of the sensor and measure the clearance between the throttle limit screw and the stop lever with a feeler gauge. Move the throttle by hand, and measure the resistance between the terminals on the wire socket of the sensor with a multimeter. The resistance value should meet the requirements. The resistance between VTA-E2 terminals increases with the increase of throttle opening, and the resistance increases in direct proportion, so there should be no interruption.
② Detection of voltage
When the ignition switch is in the "on" position, use a voltmeter to measure the voltage between terminals Vc-E2, IDL-E2 and VTA-E2, which should meet the requirements; If not, replace the throttle position sensor.
4 Dual Variable Resistance Throttle Position Sensor
In electronic throttle system and electronically controlled diesel engine system, double variable resistance throttle position sensor is generally used. Generally, when two sensors are installed in combination, when one sensor fails, it can be identified in time, which increases the reliability of the system.
Nissan Teana dual variable resistance sensor circuit is shown in the following figure.
Engine control unit ECM provides 5V reference voltage to sensor terminal 1# through terminal 72#; Terminal 4 of the sensor is grounded through terminal 36 of the electronic control unit. TPS 1 and TPS2 throttle position signals output from terminals 2 and 3 of the sensor are sent to terminals 33 and 36 of the engine control system respectively.
The inspection method of dual variable resistance throttle position sensor is as follows (taking Nissan Teana as an example):
Turn on the ignition switch, shift the shift lever to D (A/T) or 1 gear (M/T), and check the voltage between ECM ports 33 (signal of terminal of accelerator position sensor 1#) and ground in different states of accelerator pedal with multimeter voltage gear. The inspection results shall meet the requirements in the table below. If not, replace the throttle body assembly.
5 Hall throttle position sensor
The valve position sensor has two sensor circuits: VTA 1 and VTA2, and each circuit sends out a signal. TA 1 is used to detect the throttle opening, and VTA2 is used to detect the fault of VTA 1. The sensor signal voltage varies from 0 to 0-5 volts in direct proportion to the throttle opening, and is sent to the terminals VTA 1 and VTA2 of the engine control module.
When the throttle is closed, the output voltage of the sensor decreases; When the throttle valve is opened, the sensor output voltage rises. The engine control module calculates the throttle opening according to these signals and controls the throttle actuator to respond to the driver's input. These signals are also used to calculate air-fuel ratio correction, power boost correction and fuel cut control.
20 16 Toyota Camry hybrid throttle position sensor detection method:
① Check the sensor power supply.
Open the throttle body connector E 16, and use a multimeter to detect the voltage between E 16/5 and E 16/3, which should be 4.5~5.5V, otherwise check the ECU power supply circuit. If the ECU power supply circuit is normal, replace the ECU.
② Check the signal voltage of the sensor.
Connect the scan tool, turn on the ignition switch, press the accelerator pedal, and read the throttle position sensor data VTA 1 and VTA2. These values should conform to the following table.
③ Check the sensor harness and connector.
Disconnect the throttle body connector E 16 and the engine control unit ECM connector E8 1, and check the resistance between the connectors or between the connectors and the body ground, as shown in the following table. The resistance value should meet the requirements in the table. If not, replace or check the harness.