That could be a DLM issue. If it's a traction, even older models have door lock monitoring. Northerns are designed to go on inspection mode if there is a door contact mismatch at full open, once the mismatch is eliminated, it will automatically return to auto mode as long as no inspection switches or door lock bypass switches are activated. Check to make sure all door locks are making (cabin and hall) only in the door closed position. Also make sure DCL=0 on full close Make sure no in-cabin inspection/access switches are not set to auto. The door signals should be set to the following at full open in order for doors to close: DOL=0=DCL6/DPM/BYPASS (if provided)=Gate SW.=Hall locks (top, middle, & bottom) AND DCL=1. If anything other than DCL is active at full open. That lift ain't going anywhere! The same goes for both DOL and DCL being 0 simultaneously.

All the doors and dcl and dol are correct. It will do a 1 floor run on auto , once it gets tot he floor it announces the floor it’s at then says this car is on inspection. No faults , does not show it’s on inspection in the controller . Just sits with doors open . If you close the doors it will do another 1 floor run.

Are any jumper cables left behind? Check for faulty inspection switches and door bypass switches.

Also check in-cabin insp switch.

No jumpers . Checked all switches , everything is normal. All inputs are in proper state .

It’s like it’s shutdown on counts but won’t reset .

Be sure relay IRR picks and drops after each run. Also be sure to check that the contacts themselves are good.

The IRR input doesn’t stay in a solid state when it hits the open limit. It toggles back from 0-1 fast

That might be your problem.

Any way to test / verify that it’s the irr input ?

Yeah…the Northern tool. On the left side of the upper control board you can see inputs like CHC, is IRR one of those? I can’t recall. You should be able to see after a run whether one floor or whatever, if the relay drops and picks or picks then drops. Whatever state it’s in after you reset it, is the normal state as it does initiate drive to answer the call.
Is there by chance an LCD display screen on this controller?

Yes there is a small LCD display on the front board . There’s no IRR input visible on the board .

Re reading your original post, you say it will “run properly with doors closed”. So I think that might eliminates the IRR thing. JJR eluded to door signals earlier, have you checked those door position signals?
ECI door operator? Be sure there are no loose cams and that all signals occur at the proper time. Same with terminal strips that the integrity of connections are tight. I believe you’ve covered those items.
At full open, be sure the detector edge cable(s) aren’t grounding or becoming “open” due to chaffing or pinching on the corner post, pinched on the cable hanger on the car door header or rubbing through the cable insulation on the car door itself.
And I don’t believe the Northern units utilize a pre opening on doors.
Hopefully you’ll get to the bottom of this soon!

Northern does have pre-door. Most of them that have it are the pre-Thyssen era relay versions (Normic).

PS: I'm surprised anyone would even have trouble with a Northern. It's the best company ever. The only brand of elevator I've never been stuck in and never had issues with.