Details of the electronic throttle (wiring, internals)
The connector has 6 pins labeled A-F.
A, B have to be the driver input (1 ground, 1 servo pulse).
I can't tell yet for the other 4. I need a better way of clipping my meter on these leads. If no one knows, I'll grab some tiny spade connectors tomorrow and try again. C-F are all connected (1.4k-4.21k between any two pins in this group, varies by which pair of course).
Pending questions:
1) What's the polarity of the drive pins A,B
2) What's the servo pulse frequency (I can test this if I find someone with a gto or vette)
3) What exactly are the pins C-F?

With the throttle in the closed position:
Rcd = 3.29k, falls as throttle opens
Rce = 1.41k, constant as throttle opens
Rcf = 1.47k, rises as throttle opens
Rde = 2.62k, rises as throttle opens
Rdf = 4.21k, constant as throttle opens
Ref = 2.14k, falls as throttle opens
I did note that Rcd+Rcf=Rde+Ref = 4.76k
Still unsure of how how it works out internally though.
Last edited by 280Z28; Nov 10, 2006 at 06:13 PM.
C: Position sensor 1
E: Position sensor 2
D: +5V ref
F: Gnd
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I'm controlling the throttle with a simple PID controller for a constant frequency square wave with varying duty cycle. My supply voltage is 5.17V with ~1V drop across my low side driver. The controller sits right around 50% duty cycle to keep the servo open to position A. A reference source (that link 1 post up) states that it should take a 14-26% duty cycle to keep it open to position A.
By my calculation, I've applied an effective (time averaged) 2V source.
2/.26 + 1 = 8.7V
2/.14 + 1 = 15.3V
Is this the correct calculation/conclusion that the servo is built to handle a 9-15V supply? It sure makes perfect sense in an automotive application...


