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HTMtrSprt
October 7th, 2008, 05:47 AM
Has anybody had a problem getting the E38 to engage PE mode? I have a '07 Suburban w/ a magnacharger that I set the TP to engage PE mode at 44% @ 2000 RPM but it won't enter PE until about 70% throttle. btw - 12608677 OS.

HTMtrSprt
October 7th, 2008, 06:18 AM
I just found a thread that seems to address this same issue (http://forum.efilive.com/showthread.php?t=6461), but no fix was given. Has anything been found since then?

XLR8NSS
October 7th, 2008, 07:34 AM
I had the same problem with mine. I didn't fix it myself but, you can look at my tune if you would like.

'07 GMC Sierra 2500HD(New body style) with TVS 1900 Magnacharger. :)

GMPX
October 7th, 2008, 09:38 AM
Make sure your ramp in rate is high enough {B0169}.

swingtan
October 7th, 2008, 10:07 AM
By my calculations, I'd say that if you set the TPS to 44% in the tune, then the actual logged data will indicate that PE is entered at just over 66% TPS. I know that there are a few theories about this, but I've consistently seen that for PE, the TPS% parameters are different between the logged data and the tune file. If you actually want PE to come in at 44%, try setting it to 13% in the tune.

Also as indicated, you may want to speed up how fast the PE AFR is reached by increasing B0169. I currently have this set to 0.80. I've attached a graph comparing the tune TPS vs logged TPS for PE mode.

Simon.

HTMtrSprt
October 7th, 2008, 11:59 AM
Thanks..... I entered in values along the lines of the table in the other thread and it works great now; 14% enters PE at about 45% actual throttle.

GMPX
October 7th, 2008, 03:21 PM
There is basically 4 main criteria to enable PE.
Throttle Position
MAP
RPM
AFM Mode

It's like this -
If RPM > B0155 AND
If MAP > B0157 AND
If TPS > (B0156 + B0157) AND
Engine not in AFM Mode,
Then the ECM will start the PE delay timers. Once they have expired the P.E Fueling AFR will be ramped in based on the rate value in B0169.

I am attempting to add in some more throttle PID's that will be related to the actual values used by some of these tables.

Cheers,
Ross