Electronic Throttle Body Tester

[techneo]

Hi,

I want to design a tester for Electronic Throttle Body of Toyota X car. This throttle body has a six pin connector which is interfaced to the ECM for normal operation.

I have searched quite a bit but could only find schematics for Throttle Sensor as given below:
Since +5V is applied as Reference voltage to the sensor, the output of the sensor is read by the ECM to confirm if the throttle plate has deflected or not. A voltage of 0.3 to 0.8V correspond to a fully closed throttle plate while 3.2 to 4.9 V indicates a fully open throttle plate.

The  information missing  in all of Toyota documents regarding the Electronic Throttle Body is the voltage applied to the Throttle control motor inside the Throttle Body which i think must be a stepper motor. Moreover, pinout of the 6-pin connector is also not given.

 Information in this regards will be highly appreciated...

-techNeo

[pickit2]

It must be the voltage feed from the main fuse. ie. 12v

[techneo]

It must be the voltage feed from the main fuse. ie. 12v

Yes ... this is it. Now i am able to comprehend the whole picture . The throttle actuator motor is not a stepper motor but a normal DC motor driven either thru a half or full bridge circuit inside the ECM. The six pin connector has two wires for +12VDC, one each for the main & stdby throttle plate sensor and a pair for the +5V/Gnd supply.... Perfect......

-techNeo

Posted on: September 09, 2019, 02:46:17 02:46 - Automerged

It must be the voltage feed from the main fuse. ie. 12v

Hi,
  While looking at the schematics, it is mentioned that the +12 V supply to the Control motor will be pulsed. Does it mean that i have to use a PWM signal for controlling the motor?. Because i read somewhere, that the motor used in the ETC is a BLDC instead of a brushed DC motor and would need a PWM signal for precise positioning?

-techNeo

[pickit2]

1: +5 for sensor
2: main position feedback
3: backup position feedback
4: ground

5: 12 v motor drive
6: 12 v motor drive

Note the type of motor is like the ones in printers only two wires to drive the print head.
position sensor feedback for head position. 

[techneo]

1: +5 for sensor
2: main position feedback
3: backup position feedback
4: ground

5: 12 v motor drive
6: 12 v motor drive

Note the type of motor is like the ones in printers only two wires to drive the print head.
position sensor feedback for head position. 

Ok. We would use a PWM signal ...probably at 1 Khz ( the PWM freq will be determined by the time constant of the DC motor).
I think that i need to use a PWM freq of 20 Khz ( got it from Utube videos)  to determine the speed of rotation....

-techNeo

[Checksum8]

Ok. We would use a PWM signal ...probably at 1 Khz ( the PWM freq will be determined by the time constant of the DC motor).
I think that i need to use a PWM freq of 20 Khz ( got it from Utube videos)  to determine the speed of rotation....

-techNeo

It may use what is know as "locked anti-phase". An h-bridge is fed a pwm signal, which is usually around 20khz. Designers use 20khz so humans can't hear the coils humming. At 50% duty cycle the motor is locked. If greater than 50% the motor moves one direction. If less than it moves in the opposite. The motor has an optical encoder that feeds back position information to the cpu. A pid routine is preformed to match the target signal(gas pedal) to the current motor position( carburetor valve).  Target position - motor position = error signal.

In the last few years Toyota had some throttle sticking problems. I would rather have a spring loaded cable or linkage.

Here's a video that shows locked antiphase
https://www.youtube.com/watch?v=zu6k8kHkd9M

[techneo]

It may use what is know as "locked anti-phase". An h-bridge is fed a pwm signal, which is usually around 20khz. Designers use 20khz so humans can't here the coils humming. At 50% duty cycle the motor is locked. If greater than 50% the motor moves one direction. If less than it moves in the opposite. The motor has an optical encoder that feeds back position information to the cpu. A pid routine is preformed to match the target signal(gas pedal) to the current motor position( carburetor valve).  Target position - motor position = error signal.

In the last few years Toyota had some throttle sticking problems. I would rather have a spring loaded cable or linkage.

Here's a video that shows locked antiphase
https://www.youtube.com/watch?v=zu6k8kHkd9M

Wavo.... great... You are the first one from whom i have heard this term " Locked anti-phase". Overall it is a very good idea from the standpoint of economy of hardware. Will definitely try it out....

Genuinely appreciate your effort....

-techNeo