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Old 11-11-2021, 08:12 PM   #16
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Join Date: Aug 2014
Location: Boulder CO

Did you adjust the 2 pots (the little yellow things with a tiny brass flat-blade screw on the top) per the MS instructions? And, just to be sure, does +5Vref measure a steady +5volts on the TPS, or anywhere else it's connected to outside the MS box?

The 470 ohm pullup resistor on the cam circuit is OK, and the 3.5v is too.

[technical details: the cam circuit uses the opto-isolator circuit, with one side of the LED grounded and the other side of the LED connected to the open-collector CAS pin, with a 470 ohm pullup. When the CAS isn't grounding the pin, the pullup turns on the opto LED, and the voltage on the CAS pin is the LED on voltage, plus a couple internal diode drops, so ~2.3v + .6 + .6 or ~3.5.]

Can you measure the voltage on the J1-1 wire (the output of the opto circuit) while turning by hand? This should swing ~0v to ~5v.
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