Engine Torque Control Signal how does it work.

[Dessertrunner]

Could some one explain to me what and how the Engine Torque Signal Works understand it is to reduce torque when transmission changes and with throtle closed it and in Netrul is +5V. What is it at full power not during a change?
Tony

[Dessertrunner]

Ahve a 5 speed and put switch between pin 16 torque control and 5 v and got no difference in power. Also messured the voltage on the ECU end of 20 and got 5 v anyway so tell me does the pwer come from taking pin 20 to 5 v or ground because I don't seem to be able to tell. Haven't tried grounding 20 as not sure if safe.
Tony

[oab_au]

Ahve a 5 speed and put switch between pin 16 torque control and 5 v and got no difference in power. Also messured the voltage on the ECU end of 20 and got 5 v anyway so tell me does the pwer come from taking pin 20 to 5 v or ground because I don't seem to be able to tell. Haven't tried grounding 20 as not sure if safe.
Tony

Tony the line from the TCU is held high, 5V, when the TCU wants Torque cut, it pulls the line low, 0V. I think most just leave it unconnected. I would wire it to 5V, to prevent it from giving any problems. Of course where you can get the 5V from,,,,I'll have a look and get back.

Harvey.;)

[Dessertrunner]

Harvey that makes sense and I don't think you have to connect it as the ECU reads 5V standard so that explains why connecting to 5 V did nothing. You may be right to leave it alone.
Tony

[longassname]

Actually, I don't believe the tcu holds the signal path high. I believe there is a pull up circuit in the signal path in the ecu. The pull up circuit makes it un-necessary to connect it to a signal source to prevent the circuit from floating.

[dynomatt]

Can you explain that a bit more for the nuffies like me?

[Dessertrunner]

Matt what mike means is its a typical electronic circut which can be either high or low. The ECU circut has a resister or something simlar that holds the input at 5v if the pin is grounded the amount of leakage won't satisfy the load and the pin will be pull low. The sensing side of the circut is effect when the wave form goes from high to low. May be if you think of a rope being pulled at both ends and one end has the advange and is winning being 5V now we add some people to the other side and the rope moves to the ground side. As the ropes move in the new direction the movement is picked up.
Hope that helps it seem that most of the electronic circuts on the SVX operates on the same princple.
Tony

[longassname]

ttl circuitry uses 5V signals. 5V is a high state. 0V is a low state. Of course no Voltage is exact. Consider 4.9999999999V that's not really 5V. So every particular ttl device has defined voltage ranges which it will react to as a high or low state. A connection to ground provides 0V and is the typical way to signal a low state. No connection theoretically provides 0V and typically registers as a low state. A non connection is called a float. It is not good design practice to use a float to signal a low state. If we want to default a signal to low we use a pull down circuit. A connection to ground through a high resistance. This provides the default low signal. Then to signal the switch to a high state a connection can be made to the +5V rail. Because the pull down circuit has a high resistance the +5V connection easily overrides it to provide the necessary V to signal the high state. Similiarly when we want the default signal state to be high we use a pull up circuit and to signal a low state we override it with a connection to ground.



Can you explain that a bit more for the nuffies like me?

[dynomatt]

But of course!!!

Based on that, is the 5V that seems present in Tony's circuit a "floating" 5 volts, which based on my interpretation of what you've just said, is a bit flexible, or, given he wants a proper 5v, is it better to get a 5V bus source and hook it up...avoid the risk of it floating?

I'm in the same boat, and based on Tony's test last week, I wasn't going to touch mine, but if it's floating, and in the middle of going up a hill, and for whatever reason it drops down and the torque control kicks in, goodby 20-30kw...not so hot.

Matt

[Dessertrunner]

Mike if we wanted to run a test by connecting to ground to confirm it will change the engine running state would we need to have a resister between ground and the pin so as to not direct short. Are all the circuts in the car ttl or are some Cmos I just would have thought ttl was old technolagey.
Tony

[longassname]

a float is not 5v. A float is a non connect and is theoretically 0v. I say theoretically because noise can be picked up to make a small voltage. That's why it's not good design practice to use a float as a signal of a low state.

The ECU signal path has a pull up circuit. Because it has a pull up circuit when it is disconnected from the tcu instead of floating it is held at 5v and there is no need to connect it to an external signal.

[Trevor]

Tony the line from the TCU is held high, 5V, when the TCU wants Torque cut, it pulls the line low, 0V. I think most just leave it unconnected. I would wire it to 5V, to prevent it from giving any problems. Of course where you can get the 5V from,,,,I'll have a look and get back.

Harvey.;)

This instruction is bad news.

As has been clearly and wisely stated on a basis of logic, it is highly undesirable in this instance to apply a voltage to the incorporated divider network.

[oab_au]

a float is not 5v. A float is a non connect and is theoretically 0v. I say theoretically because noise can be picked up to make a small voltage. That's why it's not good design practice to use a float as a signal of a low state.

The ECU signal path has a pull up circuit. Because it has a pull up circuit when it is disconnected from the TCU instead of floating it is held at 5v and there is no need to connect it to an external signal.

Thanks for expanding that Mike,:) yes the wire from the ECU to TCU is held high by the ECU, and is only a few inches long, so it probably won't be a source of interference, or concern.

Harvey.;)

[oab_au]

This instruction is bad news.

As has been clearly and wisely stated on a basis of logic, it is highly undesirable in this instance to apply a voltage to the incorporated divider network.

This post shows that, the reader has no idea, what we are talking about.:D

Harvey.;)

[oab_au]

Mike if we wanted to run a test by connecting to ground to confirm it will change the engine running state would we need to have a resister between ground and the pin so as to not direct short. Are all the circuts in the car ttl or are some Cmos I just would have thought ttl was old technolagey.
Tony

If you wanted to pull the line low, you wouldn't need a resistor, just ground it. Most of the electronics are CMOS, but the TTL signal is used between control units, as the stronger signal is more immune to interference.

Harvey.;)

[Trevor]

If you wanted to pull the line low, you wouldn't need a resistor, just ground it. Most of the electronics are CMOS, but the TTL signal is used between control units, as the stronger signal is more immune to interference.

Harvey.;)

Your previous post indicated application of voltage.