Reduced engine power after autoTune

[mtnman]

I was going through the Updated AutoTune Tutorial (10-02-05), loading the Map table changes to B0101 and every time I took a test drive and got above 3000 RPMs for any length of time the "reduced engine power" message came up and the engine bogged down.

After setting the P0101, P0102, and P0103 back to MIL (instead of NO MIL) and enabling the cat converter B0701, the problem seems to be gone. Anybody else had this problem?

[Dirk Diggler]

if you are throwing P1514 gor into table C6010 and rasie all the values by 20% or so

[mtnman]

Yes, it was throwing P1514 codes. {C6010} doesnt exist within my tune.

[mtnman]

Looks like "dfe1" may have answered my question:

" Also note that if you convert to MAFless, you'll have to do some considerable rework to the predicted airflow table. If you don't and actual air flow exceeds predicted, the system will go into reduced power mode. No big deal, and easy to clear, but the throttle will have no effect until you clear the codes."

More work on the airflow table?

[Dirk Diggler]

Yes, it was throwing P1514 codes. {C6010} doesnt exist within my tune.

Sorry i meant C6101 that is the predicted airflow table

[GMPX]

Didn't someone create a scantool map for this?.

Cheers,
Ross

[dfe1]

One way to eliminate the problem is to set the values in the predicted max airflow table (C6101) to maximum. Not a good idea because that removes a safety valve. Instead, log Air Flow Grams/Cyl and when you set the code, you'll know what table cells to change. Do that a few times and it will be pretty easy to develop the values you need to redo the whole table. I'd be happy to send you the table I developed, but since it's for a C5, it will only be a starting point-- truck engines run under a condsiderably heavier load than passenger cars because they're 2,000- 3,000 pounds heavier.

[Black02SS]

Didn't someone create a scantool map for this?.

Cheers,
Ross

Sorta. He created a MAP and was using that ONLY to adjust for his AFR. Did not touch the VE Table at all.

[caver]

If you adjust the VE table without doing anything to the maf table or vice versa you can get errors because the ecu is always comparing the 2.

The maf map was to use after you set the VE table up I use it all the time and it works perfectly.

[mtnman]

I was trying to do the AutoTuneVE tutorial and got this and other errors. I was hoping that following the tutorial would be pretty much a "cut-and-dry" process. The day after I thought that I had the LTFTs tweaked, the engine light came on. I didnt have time to check the codes, so I just resorted to the pre-autotuneVE tutorial *.tun. I'm not dogging the tutorial or the product, since its probably mostly user error, but it just seems like there are more problems than there should be when following a documented tutorial such as this. I've gone through this tutorial over and over about 5 times and things just dont sink up. I've noticed one obvious error where it mentions saving the tune file as one name then it states to flash another *.tun file to the pcm on the following line.