new SD2 1.2 chip weirdness?

[JDEstill]

I recently got the latest SD2 chip upgrade from Eric, version 1.2. Got the latest PL software, 2.5.2.

Only been running it a few days. An odd thing happens - when I give it enough throttle to get up to about 0 psig boost, the SES light comes on. Let off the throttle and it goes away. It does not throw a code, at least nothing that the PL picks up and saves.

Anybody know what is going on here?

I did check the shift light feature, and cell 15 of the BLM grid is set at 254, so it shouldn't be that coming on prematurely.

BTW, maybe it makes a difference, I do not actually have a flexfuel sensor installed yet. I do put a few gallons of E85 in the tank and adjust cell 13 in the BLM grid to compensate for it, based on the corrections I see on the PL after a fill up. Right now I have it at 131 for example. Been doing that for a while. I didn't think I needed that sensor hooked up to run the SD2 1.2 chip, but maybe I am wrong about that.

John

 

[DavzGN]

If you have the flex fuel option turned off you should be fine. I don't remember the setting that needs to be changed. Also check the overboost settings.

 

[Eric Stage I]

Make sure also reflashed the PL with PLo44

 

[JDEstill]

My options are currently set at "3", so flex fuel should be turned off.

I thought I reflashed the PL with PL044, but I will reflash it to make sure and report back.

John

 

[Eric Stage I]

Like DavzGn said, it could also be the overboost settings on the PL parameters page. Set them both to 100 for now, which should shut it off.

 

[JDEstill]

hmm... I had not looked at those overboost settings before. Now that I am looking at them I have no idea what they do exactly, and I don't see it in the manual. Is there an explanation somewhere? I see 3 overboost settings, one at 19.5 psi and the other 2 settings at 0. I assume these were defaults, I wouldn't have touched them if I didn't know what they do. Which do I set at 100? Attached is a log file from the other day when I tried to catch a trouble code. Taking off from a stop in the latter part of the log is where the SES light turned on. File has my tune in it as well.

 

[Eric Stage I]

They will default to 100 if you loaded up the defaults when installing the new chip (set chip param 16 to 1).

Here is how they work (this isn't in the manual yet):

Overboost Immediate PSI (default 100psi)
Boost PSI above which the wastegate DC will immediately drop to zero %.

Overboost Delayed PSI (default 100psi)
Boost PSI above which the Overboost Delay timer will start. When the timer expires, the wastegate DC will drop to zero %. This parameter allows for an overboost condition for a short time before setting the wastegate to zero.

Overboost Delay (seconds, default 0.0)
Used with the above Overboost Delayed PSI parameter. After the Overboost Delayed PSI threshold is met, this amount of time will pass before setting the wastegate duty cycle to zero %.

You can also command these parameters to set the injector duty cycle to zero % (in addition to wastegate) if you set the Options parameter to 8. If you have other options already set, then add 8 to those.

 

[Eric Stage I]

I forgot to add that the SES light will come on also, when those thresholds are met. It is reset when letting off the gas.

 

[Eric Stage I]

Updated instructions: http://www.turbotweak.com/sd2instructions11.pdf

 

[TurboBob]

The fuel cut overboost protection works well, cuts clean, etc.

But do NOT use the fuel cut if running alky, for those cases the warning (SES light) and boost cut should help protect you.

Bob

 

[JDEstill]

Thanks for all the info Eric! I thought I tried a reset when I put the new chip in, to see if anything was different, but if I did I didn't save it. For sure I reloaded my previous tune before I started driving it. I'll do that again and see what comes up. In the meantime, I'll change those parameters and give it a try. Sure sounds like that could be my issue!

John

 

[JDEstill]

Finally got a chance to give it a try. The problem was in fact the overboost settings. Got those squared away and problem solved! No SES light, and the car feels a whole lot better when I get on the gas

Thanks!

John