COS5 nitrous activation issue

[joeygc5]

I finally converted my 2001 Vette to use os 12212156 and cos0202005. The Car runs perfect and on a nitrous tune there are no issues. I'm using my window switch to activate the nitrous/fuel relays and pcm pin 56 sink relay. The pcm no matter what settings I try will not retard timing when the pin 56 input is grounded. I have 10.96vdc at the wire connected to pin 56 measuring open circuit, and 12.5 volts on the pcm supply when the vehicle has key on but not running. Any suggestions? I've tried activating it and different MAP and RPM levels with no success. I know there are 2 out of range cos parameters, but I can't get them to clear even when adjusting the values in range of limits.12815

[joeygc5]

I'm also running the same 12212156 and cos 0202005 in my 2001 GMC turbo truck with dry nitrous control and no issues. unfortunately it's at the chassis shop getting the rollcage put in.So I'm unable to do a side by side evaluation. Any Suggestions?

[joeygc5]

Well the only out of range table now is A0011, which I don't understand being its a cos value, set to N20 monitor. Open circuit voltage on pin 56 to engine block and /or battery ground is 12.96vdc and battery voltage is 13.6vdc with engine running. I've tried every value adjustment for the n20 monitor enable functions with no success. I don't get it, electrically everything is correct. I'll try to reload the cos and then load the tune to see if there is any change.

[joecar]

A0005 and A0011 are out of range...

A0005: set this to 7999 (but this is beside the point).

A0011: set this to Not Used, save file, exit the tunetool; restart the tunetool, set it to N2O MOnitor, save file.

[ i.e. bringing OOR values back in range is a two step process, it's quirky, but be aware of it ]

[joeygc5]

Sob, did the unselect and then reselect as suggested. Works like a champ

[joecar]

You got it working, cool :cheers:

[minytrker]

What Joecar wrote is exactly what I do also. I ran into this years ago. I now always make sure there are no out of range on anything I tune. Its a good habit to get into and I have since then never had an issue with the COS inputs/outputs.

[joecar]

There is a quirk:

when a cell is OOR, the tunetool displays the closest IR value (which will be either min or max) and marks the cell with blue dog-ears...

now if you set this cell to min or max, the tunetool sees no difference compared to the displayed value, and when you save the file nothing gets written;

so you have to force a save by setting the cell to a completely different value (and saving, exiting, re-entering, and now setting your max or min IR value).

[ I hope I wrote that understandable... if not, pm me your phone number :) ]

[joecar]

+1 what minytrker said, make it a habit to check that all cells are in range (A0012, A0013 are usually not listed, but check those also).

[joeygc5]

No I understand this, it's just no matter what settings I was doing those 2 tables wouldn't go into range, until I read the tune then changed the A0005 to a sane value and reloaded. Then using the deselect, save, and reselect method A0011 finally came into range.

Thanks for the help.