constant automatic transmission KR

[Jmaurer]

I have scanned multiple stock automatics, gen 3-5, and they constantly are pulling timing. Even very low milaged cars. I'm used to scanning manuals and never see this issue. I've turned burst knock off but it still continues. I can't determine how much timing I can add because its already showing KR with the stock timing table. It will occur all over the table and in different gears. I thought maybe it was an overdrive thing but the KR will even occur in other gears and just driving around. Ive tuned the LTFT's to 0 to -2. the KR spikes to 8 at some points so its not even a low number. Can anyone elaborate or give advice how to handle this and if this is normal for an automatic car?

[5FDP]

In the earlier GEN 3 vehicles, if the timing spiked to 8 degrees it was normally a bad knock sensor or harness. You'd likely see a pending code for one of the knock sensors.

I didn't see this problem with my 2012 with the 6L80e and even now with my 2016/6L80e truck. Sure I got little random bits of knock at time and if the torque converter locked up in 6th gear at a low speed and I gave it a little throttle.

[Jmaurer]

hmm. thanks for the info. im looking through a log file right now to see if anything pops out at me.

[eficalibrator]

Are you confusing Knock Retard with Torque Management during the shift? The TCM requests a reduction in torque from the ECM while the clutches are not fully applied in order to give them a chance to apply smoothly without too much slip/damage. This torque reduction is largely accomplished via spark retard.

[Jmaurer]

I was wondering if that showed up as retard or the computer just expects it. but a lot of this is occurring just during in gear driving well before a shift and in lower gears as well. you are correct tho, I do see higher values before the shift. I've dialed the TM back some per whatever they wanted. ive just been trying to add timing and even 1 degree sends the KR going crazy everywhere. Its a 5.3 with around 20-30k on it so I'm rather confused in this situation why that occurs. I thought there would at least be room for 1 degree being I seen a lot of people on here can usually get 3 more degrees out of a stock setup. I do a lot of timing tuning on manual cars because all this crazy KR doesn't occur. ive rode in aa auto 2016 Camaro with less than 10k miles on it just to scan it for transmission changes and even with factory timing it was constantly pulling it being in gear and now making sense before shifting. im not hearing any knock and these auto's are driving fine. I just figured there is something I don't know about automatics so ive never adjusted timing on any autos unless the person really wants me too because if I don't understand something im not the type to just do it and see what happens. ive got some automatic cam cars coming up and ive been wondering what im going to do if this occurs with those cars. ive usually done setups just not with different cam. But I feel comfortable enough to start into the cam side. the only thing at this point I feel will be a struggle with me is adjusting timing to an actual better performance value instead of staying alot lower than it could be to be safe. it probably sounds bad but im not scared to admit it.

[wburk]

Post a tune file and a log file for everyone to see and we may better be able to answer or point you in a better direction.

[Jmaurer]

I haven't had a chance to log the truck in awhile so as soon as I do I'll post it. Thank you for your help!