04-25-2020, 12:28 AM
Popgun wiill likely be your best help with the oscilliscope, but the issue is less likely to be the ECM pulses to the stepper motor.
The problem is most likely the IACV stepper not moving in direct relation to the pulses. It has no feedback, unlike a servo motor with an encoder, hence no associated DTC for position error.
Steppers are very accurate, within torque limits. Above torque limits, there is no certainity of proper movement for each pulse. Thus, if the IACV piston is not free to move, position will be off. Winding resistance may be within spec, but there is no diagnostic in the service manual for IACV piston free travel.
https://www.amci.com/industrial-automati...-vs-servo/
In 1984, I was a regional sales rep for power transmission eqipment (clutches, brakes, gear reducers, motors, chain, belts, etc.) One of the lines was Superior. I got into the industrial automation business by accepting an employment offer from a client. When I retired, 35 years later, Kollmorgen was the ultimate.
https://www.kollmorgen.com/sites/default...tric_0.pdf
When I operated a motorcycle tuning shop in seventies and eighties, it was carbs and points, a few electronic ignitions (Martek 440 in my 1976 CB750); so most of my stepper/servo experience is industrial or automotive.
https://www.assemblymag.com/articles/918...aceability
I retired Feb 2017, then Calmation closed May 2017, so website info is all gone.
The problem is most likely the IACV stepper not moving in direct relation to the pulses. It has no feedback, unlike a servo motor with an encoder, hence no associated DTC for position error.
Steppers are very accurate, within torque limits. Above torque limits, there is no certainity of proper movement for each pulse. Thus, if the IACV piston is not free to move, position will be off. Winding resistance may be within spec, but there is no diagnostic in the service manual for IACV piston free travel.
https://www.amci.com/industrial-automati...-vs-servo/
In 1984, I was a regional sales rep for power transmission eqipment (clutches, brakes, gear reducers, motors, chain, belts, etc.) One of the lines was Superior. I got into the industrial automation business by accepting an employment offer from a client. When I retired, 35 years later, Kollmorgen was the ultimate.
https://www.kollmorgen.com/sites/default...tric_0.pdf
When I operated a motorcycle tuning shop in seventies and eighties, it was carbs and points, a few electronic ignitions (Martek 440 in my 1976 CB750); so most of my stepper/servo experience is industrial or automotive.
https://www.assemblymag.com/articles/918...aceability
I retired Feb 2017, then Calmation closed May 2017, so website info is all gone.