MoTeC Global Forum

Hey guys,

I've done some searching and having an issue with my Stepper motor built into my throttle body.

I have quadriple checked the wiring compared to Motec's datasheet, even bought another motor.
or the life of me I can't get it to move.

If i key off and on, i feel the motor pulse once and not do anything again.

Verified the wiring to the coils internally and verified continutity through my engine harness, firewall connectors all the way back to the M800.

When Key is on, I have measured at the IAC Plug and have 12V across two pins (A&B) and 4V across (C&D). C&D have been reversed in the wiring as per the Datahseet and i have tried reversing those as well to no avail.

Tried setting initial position to 200 and -200 in order to either fully shut or fully open the motor, as well as reversing the C&D Pins.

Attached is my tune file incase I have done something stupid!

Should the two middle pins measure as Positive or Negative for the stepper?



I know this picture is from the MS Website, but it has an illustration that works for me.
My Motor is like the center item.

Thanks!

Hello,
This is the diagram I always use for the GM style stepper motors. The idle control setup in your ECU looks basically correct except you don't need any integral gain at all for a stepper motor.

How are you testing this? The idle control will only work below 1500rpm, 2% throttle and 4km/hr ground speed according to your set up.

Hi Mark,
I am basically just keying on and off to se if it moves to any initial or normal step counts.
Also if I change polarity on the AUX Output the motor won't move in or out as I've read in previous posts.