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GAMEOVER
April 19th, 2010, 11:22 PM
Working on a GEN3 2002 5.3ltr motor in a Sandrail(Off Road Only)....Owner wants to run OLSD, no O2's, no MAF. Will it make a difference, or matter if under Engine DTC Processing Enabler's I change all O2 sensor's from "2 trips, Emission Related" to "Non-Emission" or "Not-Reported"?
I thought I read a post/thread about it somewhere on the forum(can't find it) where it said it did matter...

WeathermanShawn
April 20th, 2010, 12:20 AM
Gameover:

Joecar recently highlighted that unless you throw a DTC your MAF is not failed.


It does, but only if C6001 has P0101,2,3 not set to Not-Reported or Non-Emissions (i.e. those two will prevent a DTC... a DTC is required for failover to VE)... not exactly 100% sure about Non-Emissions.

I.E. Do not set it to Not-Reported or Non-Emissions..

I always allow my MIL to illuminate during MAF failure and double-check that it throws a DTC..I never realized that some people change it. If anything I go One Trip, Emissions Related, to throw the DTC immediately.

I am pretty sure I got this right. Please comment if wrong..

Thanks..

joecar
April 20th, 2010, 02:35 AM
Set the O2 DTC's to Not-Reported, leave the MAF DTC's as A:1-Trip.

(SD requires a MAF DTC to be present)

If you leave the other DTC's alone, then you will have some indication when something breaks (e.g. TPS wiring, MAP sensor)... i.e. the PCM can detect wiring problems (opens and shorts and incorrect sensor voltages).

For offroad use in Mexico only.

Edit: I looked at some HSV files and I see that Non-Emissions would work also... I'll try this myself shortly.

WeathermanShawn
April 20th, 2010, 02:53 AM
Here are a few other 'sanity' checks users can use to see if they have successfully failed the MAF (other than DTC).

This is from my own personal observation of OS 12212156..

1. Log Both GM.CYLAIR.DMA and GM.DYNCYLAIR.DMA PIDS.
If MAF failed they will log identical values.

2. Only the LOW-OCTANE SPARK Table will be active. You can alter it +/- 1 degree from High-Octane to verify running off Low-Octane Spark.

3. Log GM.ASPARK. If MAF Failed it should read 0%.

Again, all personal observations. I like to log MAF Freq and g/s when I test MAF failed. The biggest hassle for me is to remember if and when you go back to MAF-Enabled, ASPARK remains at 0, until you all the parameters of B6213-B6217. That one drove me crazy for a while.

Hope that helps. Again, if I have misstated please correct. Nothing worse than tuning MAF Failed and its not..:).

-----------------------------------------------------------------
Nice one about off-road use..:cheers:

GAMEOVER
April 20th, 2010, 04:09 AM
Thanks fellas...:D
That cleared it up for me.

ScarabEpic22
April 20th, 2010, 05:13 AM
Game, check the SD mode using the methods Shawn and Joe have suggested. If the owner wants to leave it in OLSD, use a COS so retain the high and low spark tables.

GAMEOVER
April 20th, 2010, 12:42 PM
I have used SD successfully quite a few times(COS 3 & 5), but lately(OFF ROAD ONLY)GM people want to go OLSD, they want to run less & less factory sensor's and for some reason don't want to use front or rear O2 sensor's. I was really trying to understand under the DTC Processing Enablers, what to set the O2 sensor's to, when they are not being used...

ScarabEpic22
April 20th, 2010, 12:44 PM
Ive been trying to figure that out as well for a while, the DTC enablers/checks/etc arent my strong suit yet.

GAMEOVER
April 20th, 2010, 05:18 PM
Ive been trying to figure that out as well for a while, the DTC enablers/checks/etc arent my strong suit yet.

Yeah Eric, mine either...:D

WHYTRYZ06
May 9th, 2010, 04:52 PM
Set the O2 DTC's to Not-Reported, leave the MAF DTC's as A:1-Trip.

(SD requires a MAF DTC to be present)

If you leave the other DTC's alone, then you will have some indication when something breaks (e.g. TPS wiring, MAP sensor)... i.e. the PCM can detect wiring problems (opens and shorts and incorrect sensor voltages).

For offroad use in Mexico only.

u can even set it to non emissions, i passed my obd2 test w/ it set to non emissions

swingtan
May 9th, 2010, 07:05 PM
Here in Aus, semi-CL SD has been used nearly exclusively for the LS1 controller. It seems to give the best driving experience for the vast majority of people. However, when going to the E38, the difference between the SD and MAF is much less clear. My thinking at this time is that a combination of dynamics and the speed of the E38 make the MAF work much better than with the slower LS1 controller.

RE: DTC settings, I normally set the MAF to "Non-Emissions". This lets the controller know the MAF has failed but will not bring up an emissions code. You can also turn off the MIL Enabler for this DTC so there is no dash light.

For the O2's, just alter the settings in b4205 so that CL mode is never entered. Doing this means that no DTC's need to be altered at all, as they are not "failed" in this case. If you simply remove the O2's, for a track or off road car, then you will of course throw a DTC. In this case it's much less of an issue what sort of DTC you throw and the most you will need to do is turn off the MIL.

Simon.