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2 step ect.

posted May 20, 2016 06:31:12 by Inge_Jeppesen
How does the pcm know when to step up and down from cold curve to hot curve. (Changing the internal resistance on the 5v ref. To the ect)
Norway
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9 replies
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Dylan said May 20, 2016 18:26:48
Are you referring to eBook page 145?
Belgium, Europe
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Inge_Jeppesen said May 20, 2016 19:40:08
Page 6 in this video.

https://youtu.be/8Ui1679QYbs

Norway
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Dylan said May 21, 2016 12:37:45
Oh ok. This a preview video of SD Premium. Voltage, a transistor and resistors or the key words here. As you can see the voltage sensing circuit is actually connected to the base of the transistor. Just under 1 volts the voltage sensing circuit turns on the transistor base and so now the 5v ref can pass through the 1K Ohm resistor instead of the 10K Ohm.
Belgium, Europe
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Dylan said May 21, 2016 13:25:50
It's better to post this in the 'ScannerDanner book and lecture video questions' Inge. Not trying to be annoying here. On the new forums we'll be able to move threads ;-) It'll be easier.
Belgium, Europe
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PaulDanner said May 22, 2016 11:57:15
A few weeks away Dylan! Unfortunately none of this is coming with us, so at this point it really doesn't matter. Thanks bro
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PaulDanner said May 22, 2016 11:59:07
How does the pcm know when to step up and down from cold curve to hot curve. (Changing the internal resistance on the 5v ref. To the ect)

Only the aliens know who made that chip :-)

No seriously, other than a run timer, maybe an IAT reading and the voltage of the ECT itself, I have no idea
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Inge_Jeppesen said May 22, 2016 13:32:50
If the ect voltage can be the same value one time on the 10 kohm and one time on the 1 kohm. That was what I had in mind. Then the pcm could not know, based only on the ect, if it was hot or cold?

Hope you understand what I mean. 😊

Inge

Norway
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Dylan said May 22, 2016 13:46:51
I totally understand what you mean Inge. But like Paul mentions this is PCM internal regulation. Wish I could answer that.
Belgium, Europe
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Dylan said May 22, 2016 13:55:47
If I look at the Pico voltage waveform I can't see a 'voltage overlap'. At least not until 500s ... ;-)
Belgium, Europe
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