Quote:
Originally Posted by oab_au
What you have said about the way the A solenoids connections are done, is right. This is a diagram of it.
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The A solenoid is normally open, controlling a pilot pressure to control the pumps regulator pressure.
You won't find anything by looking at the voltage on these lines. The line to the dropping resistor will always be a 12 volt or 0 volt sig (depending on the battery voltage), the line to the A solenoid will always be 3 volt or 0 volt.
It is the Duty cycle that does vary. It is turned off to zero for 5% of the time, turned on to 3 volts for 95% of the time for a 95% signal.
It is not the voltage that varies, it is the current that flows during the on time, that varies the solenoids flow.
So it is not a combination of the two voltages, it is a combination of the 'on times' current that is controling the solenoid.
Harvey. |
So, you're saying the duty solenoid is operated by the current to the solenoid, not the voltage, which was my original theory before examining this circuit with a volt meter. If this is the case, then why do I observe a large voltage change at the green/yellow wire coming out of the TCU and one coming across the green/red wire to the resistor? and what circuit is in place between the two that regulates it to a constant voltage? Is this the purpose of the dropping resistor?