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View Full Version : Interesting Log File; Commanded AFR 16.00 in CL ?



chevyspence
March 13th, 2014, 03:40 AM
As this is my first post here, I would like to start off by saying this seems to be a very knowledgeable and friendly community :)

To get right to the point, I am very curious about what I have seen in a log file; commanded AFR periodically switched to 16.0 at idle and light cruise while still in an indicated closed loop status (which from what I've read shouldn't be possible on a factory LS1B OS). The measured AFR did also respond to the command.
While this may just be some silly fluke I created somehow, I figrued this might be of some interest to the rest of the community and someone more familiar with OBDII than myself might be able to identify what is causing this and how to manage it (for a potential lean cruise solution?)

The attached tune and acompanying log files were just a checkpoint before starting AutoVE and to get the WB up and running. The engine is now an 8.1 not 6.0 as referenced in the vehicle properties. While I would love to just tune OLSD and call it a day, I tow a heavy race trailer in a huge range of elevations and climates so I would like to finish it off back in CL MAF if possible.

Notes 1-6 in the log are points where commanded AFR goes to 16 in CL, note 7 is where AFR went to 13.6 for some reason...
16535 16536

joecar
March 13th, 2014, 02:31 PM
Interesting...

swingtan
March 13th, 2014, 04:38 PM
It could be lean cruise, or cat light off. I think both keep the fueling mode locked in CL, but command different fueling. Otherwise I'd be tempted to think you're not waiting the full reset time after flashing.

chevyspence
March 14th, 2014, 02:06 AM
Hmm, flash reset time as in the 15 second key off countdown? I do always make sure I allow that to complete. Unless there are some hidden tables, I think the lean cruise parameters that I can see are disabled (vss threshold) and zeroed out (EQ table). I actually tried to enable lean cruise in a recent cal and it still seemed to ignore it, which I think I've read is common for non Holden or non custom OS. I will have to go back and check the cat light off when I get home, can't remember what parameters are available...
I might be able to (and really should) take some time to get more familiar with all of the available standard PID's and custom options. I'm wondering if there are any specific PID's that I should look for that might give some clue as to what triggers the CL commanded AFR changes?

joecar
March 14th, 2014, 05:18 AM
Yes, it looks like LC is disabled.

( to enable LC, you have enable it using the cax, and then you have to do a full flash )

joecar
March 14th, 2014, 05:20 AM
Log FUELSYS-A and FUELSYS-B.

joecar
March 14th, 2014, 05:21 AM
Remove the pids OSS11 and O2S21.

Add the pids HO2S11 and HO2S21.