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E-Throttle Motor Signal Cables


Quino

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Hello!

I've bought the G4+ ECU and I have some doubts about the signals which control the E-Throttle Motor. I've seen the ECU is connected to the motor by using 2 cables (positive and negative), where the ECU sends PWM signals. I understood that polarity of the signal tells you the direction you want your valve to go (open or close) and the Duty Cycle the amount of opening (correct me if I'm wrong). But what I don't understand is, what is going on through the cables, I mean, does each cable send a PWM or negative is constantly 0V and positive sends the signals?

I would be really appreciate if someone could explain me what's going in the cables with the signals. Would help a lot!

Many thanks in advance!

Quino.

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When controlling the E-Throttle motor directly from the ECU the signal out is just a ground on one wire and power on the other with which is ground and which is positive being swapped at a high frequency. When the controller wants to move the throttle plate in a certain direction it spends more time with the motor powered one way than the other and so the motor moves in that direction. How long the motor is powered in each direction is described by the E-Throttle Motor Duty Cycle, this duty cycle is positive when the motor is powered in the open throttle plate direction for a greater period of time than in the closed direction on average and is negative when the motor is powered in the negative direction for a greater period of time than the open direction on average.

This setup differs from standard PWM in that the two wires are synchronised together so when one is high the other is always low and the onboard ethrottle controller has special hardware to actually pull the 'high' pin high to provide enough power to move the E-Throttle motor.

 

TLDR:
The E-Throttle motor is just a DC motor that is being powered in each direction alternately and the longer it is powered in one direction the more it will move in that direction.

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17 hours ago, Vaughan said:

When controlling the E-Throttle motor directly from the ECU the signal out is just a ground on one wire and power on the other with which is ground and which is positive being swapped at a high frequency. When the controller wants to move the throttle plate in a certain direction it spends more time with the motor powered one way than the other and so the motor moves in that direction. How long the motor is powered in each direction is described by the E-Throttle Motor Duty Cycle, this duty cycle is positive when the motor is powered in the open throttle plate direction for a greater period of time than in the closed direction on average and is negative when the motor is powered in the negative direction for a greater period of time than the open direction on average.

This setup differs from standard PWM in that the two wires are synchronised together so when one is high the other is always low and the onboard ethrottle controller has special hardware to actually pull the 'high' pin high to provide enough power to move the E-Throttle motor.

 

TLDR:
The E-Throttle motor is just a DC motor that is being powered in each direction alternately and the longer it is powered in one direction the more it will move in that direction.

Many thanks! I've got a better understanding now!

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Hi,

I've got another question regardless the signals of the motor. Is it possible to have an output from the ECU of the expected target TPS position? I don't know if I explain myself. In the case it is possible, in what format will the signal output will come out? (Analog? Digital? Voltage and Amperage)

Finally, just some curiosity. Is it possible to modify the current safety parameters from the E-Throttle?

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8 hours ago, Quino said:

I've got another question regardless the signals of the motor. Is it possible to have an output from the ECU of the expected target TPS position? I don't know if I explain myself. In the case it is possible, in what format will the signal output will come out? (Analog? Digital? Voltage and Amperage)

Im not too sure what you are asking or trying to achieve, but you could send commanded E-throttle target out using CAN bus.

 

8 hours ago, Quino said:

Finally, just some curiosity. Is it possible to modify the current safety parameters from the E-Throttle?

Not much, most of it is hardcoded.  

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With expected target position I mean the position the ECU wants to open the plate, so when the ECU sends to open the plate a 50%, then the TPS confirms this has happened. So I think we are talking about the same thing, tell me if not. But if it is, then I could get the signal using CAN bus? Just want to ensure, it's quite important!

Many thanks!

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I basically have to make sure that the E-Throttle works with other rules I need to apply. So for one of the rules, I need to compare the TPS with the commanded position of the plate and ensure there is no more than 10% difference between them. Therefore, how could I do it to read the duty cycles from the signals in the cables to know the position of the plate? Or via CAN, what would I have to do to send the commanded position out?

Also, could you explain in more detail how the Max and Min Clamp works?

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7 hours ago, Quino said:

I need to compare the TPS with the commanded position of the plate and ensure there is no more than 10% difference between them

The ECU compares the target to the position and shuts off the E-Throttle if the actual position doesn't track the target position properly. In other words the E-Throttle setup in the ECU already does what you are asking for so there is no need to use an external system for this.

7 hours ago, Quino said:

Therefore, how could I do it to read the duty cycles from the signals in the cables to know the position of the plate? Or via CAN, what would I have to do to send the commanded position out?

You can transmit the target and tps over CAN if you so wish.

 

34 minutes ago, Quino said:

Finally, it is possible via CAN or an Output to send a signal to the ECU to make it cut the E-throttle power supply?

If you wanted to cut the E-Throttle power supply from your own device you could set your E-Throttle Relay output to an output that isn't connected to anything and then use a GP Output to control your actual relay based on the E-Throttle Relay output (the one not connected to anything) status and the CAN input. This would not be generally be recommended though for safety reasons. Alternatively you could have two relays in series on the ECU Power and control one from the E-Throttle Relay output and the other based on the CAN signal via a GP Output.

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4 minutes ago, Vaughan said:

The ECU compares the target to the position and shuts off the E-Throttle if the actual position doesn't track the target position properly. In other words the E-Throttle setup in the ECU already does what you are asking for so there is no need to use an external system for this.

Yes, but my rule claims to shutdown the supply when this happens for 100ms, whilst according to the safety parameters from the ECU, it does this after 1s

9 minutes ago, Vaughan said:

If you wanted to cut the E-Throttle power supply from your own device you could set your E-Throttle Relay output to an output that isn't connected to anything and then use a GP Output to control your actual relay based on the E-Throttle Relay output (the one not connected to anything) status and the CAN input. This would not be generally be recommended though for safety reasons. Alternatively you could have two relays in series on the ECU Power and control one from the E-Throttle Relay output and the other based on the CAN signal via a GP Output.

I think I see your point here, tomorrow I will look into this and I'll let you know if I've got any doubts. Many thanks!!

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11 minutes ago, Quino said:

Yes, but my rule claims to shutdown the supply when this happens for 100ms, whilst according to the safety parameters from the ECU, it does this after 1s

change your E-Throttle fault delay to 0.1s

Capture.PNG

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Also, the parameter E-Throttle Relay 1 (Status) will tell me if the pin is connected? or if there is power supply or not? I mean, if there is power supply reaching the E-Throttle, is it going to have the value ON (or 1)? and it there is no power supply, I will get as a value OFF (or 0)?

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the Auxiliary controlling the ethrottle relay will show active when it has the relay turned on and inactive when it is off. There is also an Aux 9/10 Supply runtime that shows the voltage of the E-Throttle power input.

2 hours ago, Quino said:

I've got the G4+ Xtreme, not G4X. Therefore my options for the E-Throttle setup aren't same, is there a way to do it in this one?

There is not.

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