2007 SG with 110
How can you test to see if your ACR is working. I am getting the following code 1655 ACR LO. I checked power back to the fuse and that is OK.

 

The only thing I can think of is on a HOT motor:

pull the spark plug leads, hit starter, listen to how "labored" the starter sounds
then pull ACR fuse and do that again. If they're working the starter should sound a LOT more labored when the ACR's are not working.

 

pull the small wire on the starter on the sylinoid. turn key on and let all noises subside. then hit the start button. motor wont start but you should be able to hear the acr"s click open and close.

 

I am fairly certain that the HD automatic ACR's only open on the compression stroke. I do not believe this will be a valid test. You could try a compression test and see if the cylinders are near balanced.

A compression test with and without the fuse (or disconnected from the fuse) will also tell.

The ACR could be bad/electrically open and that is why the code is being generated.

 

acr's stay open all the time with start button pushed.close when there is no power to them,release start button.

 

not so sure about that.

 

Mine open as soon as ignition is turned on.Yhis was a software update by Harley.

 

Ok - original strategy was that they only opened on compression.

 

Color me skeptical about this. It seems pretty technologically advanced for an ECM to know when the cranking is on the compression stroke, especially considering cranking isn't registering RPM so the ECM would have a consistent reference point to know when to trigger the ACR like it does spark. Not to mention, different battery levels of performance regarding how fast it can crank an engine over.

The ACR is on while the start button is pressed, but if I recall correctly it's not directly wired to that circuit. I'm pretty sure there's an ECM output for it. Why that's the case is beyond me, just seems like unnecessary load on the ECM if you ask me. Mine's wired to the output side of the starter solenoid so when the starter motor has power, so do my ACR's.

 

ECM knows compression stroke because it sees deceleration on compression and can cross check with MAP signal.