Instructions for enabling semi-open loop

[Alex99]

Hi all,

I've searched the archives up and down but couldn't find what I was looking for.
I finished AutoVE and MAF tuning and would like to activate the O2s again to control the 14.63 cells in my commanded AFR map.
I'm using COS3.
What are the steps to do that?
What about LTFT and STFT?
I compared the tune before I started AutoVE and my current one and they differ in quite a few tables like PE, OL cold enrichment etc.
Do I change all that back to where I came from or do I just enable the O2s and thats it?

Thanks,
Alex

[joecar]

To run semi-open loop, setup for OL and set the B3647 cruise cells to the same AFR as in B3601 (i.e. set them to EQ 1.00).

[Alex99]

Ok, I did that already but I also have to enable the O2 sensors again by lowering the temperature limits to CL values, right?
Is that everything i need to do?
I will be using my MAF sensor, does this have any effect on running semi-open loop?

[joecar]

Alex,

No... keep closed loop disabled (keep the temperature limits to max); any B3647 cells that contain EQ 1.00 will run in SOL.

MAF is mutually exclusive of loop mode.


Cheers
Joe

[Alex99]

I'm kinda confused now.
For AutoVE I replaced the driver-side NBO2 with the LM1 WBO2. The pass. side NBO2 is still in place and connected.
My fuel map has a lot of 14.63 cells, so according to what you said, this would mean that during my AutoVE process the STFT works at least on the pass.side O2 and tries to correct any variances when AFR is commanded 14.63 e.g @ idle.
By judging my LM1, I am not at a stable 14.63 at idle but it fluctuated quite a bit in the tuning process so I doubt it was getting controlled by STFT.
I haven't logged those to check for activity though, so I will do that in the next days.

Why do we set the temp. threshold for CL anyways to the max if they still work anyways?

I'll send you a recent tune so maybe you can have a look and tell me if my settings would qualify for semi-open loop.

Thanks Alex

[joecar]

CL uses the NBO2 sensors to calculate the trim (LTFT) to apply to fueling to maintain stoichiometric AFR; the trim (LTFT) is derived in two stages (STFT and LTFT).

OL ignores the NBO2 sensors and does not trim.

Semi-Open Loop (SOL) is not CL... it is OL with the additional feature of trimming (STFT) on stoichiometric cells in B3647... this is a feature of the COS's; a non-COS that has B4206 defined and enabled can also do this.

Yes your tune file is set for OL and your B3647 has 2 areas set for SOL.

Is your LM-1's other channel simulating NBO2...?

Don't do AutoVE with B3647 set to SOL... unless you filter out SOL data from your log.

[Alex99]

Joe,
thanks for the insight. I was not aware of this fact.
No I don't use the channel simulation with my LM1. I also don't plan to keep the WBO2 in the car.
I did indeed used the VE map with those areas set to 14.63 for my AutoVE tuning. I guess this messed it up a bit?
Should I just change it to 14.7 and AutoVE again?
Then I will tune the MAF again and after that I will pull the WBO2 and put the original NBO2 in and should be fine.
When I put the NBO2 back in, I would change those areas with 14.7 back to 14.63 and should be in SOL then, right?
Other than that, I don't have to do any other changes in my tune?
I want to activate DFCO agin when I'm done. This should have no effect on SOL, right?
Can you confirm this procedure?
Alex

[joecar]

Yes, set it to 14.7 and redo AutoVE.

When all done doing AutoVE you can run SOL (I'm wondering if this is a bad acronym... ).

DFCO only activates on deccel, so you should be fine.

[Alex99]

Hi Joe,

I redid all the AutoVE and have now put the 14.7 cell back to 14.63 to enable SOL.
Today I was logging the STFT Pids and they were all at 0 and didn't change.
I have enabled the STFT in idle but I haven't seen any changes.

The AFR in b3601 is set at 14.63 (14.628...)

Is there anything that I missed or anything different that I should log.

Right now I have still the WBO2 in the driver side exhaust and only the pass. side NBO2 installed. Could that be the reason for no activity?
I want to put the driver side NBO2 in but then I can't double check with the WBO2.

Thanks
Alex

[joecar]

To do SOL you need pre-cat NBO's (or wideband NBO mode) on both banks.

What wideband do you have...?