4l60E SS3600 stall.... sometimes won't down shift or starts in 2nd

[MBC Racing]

***Added tune below**

I will post my tune when I get home later today. Sometimes, my trans will not down shift on the highway. Today, I was cruising at 70 mph, floored it and the converter stayed locked and the trans stayed in 4th. If I manually put it in 3rd, it would go in 3rd, but the converter locked right away. Later it started working normally again.... I scanned for codes and found none.

Also, If I reflash the pcm to change shift points at the track, it will basically instantly shift from 1st to 2nd for two runs. After that, it works just fine. Is there some learning going on? Are there certain codes that need to be turned off? I have data logged this in the past and can see it is briefly in 1st, then goes right to 2nd... no codes found when scanned.

Car is a 2000 Z28 and was running [email protected] pulling the left front about 3" off the ground (that is when it launches in 1st!!!) Trans is a FLT level 4 with Yank SS3600 converter.

thanks
Brad

[Russ K]

http://www.hptuners.com/forum/showth...ighlight=P0121

Russ Kemp

[MBC Racing]

Thanks for the info. I am not seeing this code when I use the cheap code reader I have in the car. I will look into it further tonight.

Also, today it got stuck in 4th on the highway with the conv locked AND later after cruising at 90 mph for about 5 min and the converter unlocked and would not lock back up. Both times I used my cheap code reader to look for a code....no codes detected. However, when I hit erase codes, it magically fixed itself!!!! So, that means to me there must be a code or two, but its not displaying?????? I will post the tune when I get home this evening.

[The_Bishop]

The converter unlocking and staying that way sounds like false misfire errors.

[MBC Racing]

haven't touched the car since my original post......

finally got some time to get out there and read out the tune so I could post it up. Here it is. Please let me know if you have any recomendations.

I would like to turn off all the trans codes. Trans is built and if there are no codes, shifts and works great. I don't want any TM or anything. Like I said, appearantly there are some codes, but they don't display on the crappy reader I had with me. Hopefully someone can tell me what is jacked up based off of looking at the tune. Otherwise i will have to go out and try to drive it and see if the HP tuners scanner will read out the codes?????

thank you