I did an EFILive COS Tune and everything is running great except I am having a Reduce Engine Power Command come on the DIC once in a while under boost and light boost but this is happening intermittently. The problem I am having is that it does not through a code to reference the Reduce Engine Power Mode. The the engine goes into limp mode, turn it off and restart runns perfect. Does anyone have any idea's as the to source of the error? (Engine, Tranny)
Also if a code was turned off in EFILIVE not to show up, could it still put the truck in to Limp Mode and not show the code like it was told to?
Thanks guys

 

I know you can turn off the MIL's but if something serious enough was happening to throw you into REP, then having the MIL off would not prevent it i wouldnt think. Did you make any changes to the tune before installing the COS? Did you follow the step by step to doing a COMPLETE reflash of the PCM? Sometimes the complete reflash can be a little tricky. Sounds like something in the tune to me. Check {C6101} and {C6102} and make sure they have been raised up.

 

I will check on the two code you gave me. Thanks, and also no changes were made to the trune before the reflash, and the complete reflash went perfect. Followed it step by step and, all the tuning after the reflash such as getting good AFR and removal of the FMU were pefrect and the truck responed good just that once in a while code no code issue.

 

Those were not codes, they are tables in EFILive.....but if you were not getting problems before the COS reflash then chances are something happened during the flash. You can try reloading the stock OS then reloading the COS again. Might wanna head over to the EFILive forum and ask there too.

 

It could be something to do with the Granatelli MAF that you are running. I would put the stock one back in and try it. I have heard that there is no advantage to running that MAF and that it might be hard to tune for. Worth a try.

Did you raise the MAF Sensor Fail High Frequency Limit. I see mine is set to 31250Hz. Because your are boosted your MAF may be seeing too much air. Also make sure that your MAF is clean.

Good luck getting it figured out.

 

I cleaned my MAF today hoping that was the issue. No success. I am going to check the limits for the MAF. I know that it has failed in the past because of the MAF seeing to much air that is why I switched to Grantelli MAF, and that took care of the problem but now after the COS a problem is back. The only thing that gets me is the lack of a code showing up. Thanks for the input.

 

Possibly MAP/MAF - throttle position correlation error. I know that will put you into reduced power, but when it happened to me, I did get the error code (running HP Tuners 2 Bar SD OS). The table in HPT is Calculated Airflow vs. TPS vs. RPM (P1514 Table) Make sure P0068 is set to SES enable and MIL on first error.

Only thing I can think of right now.

 

Guys, I'm the one helping Chris with the tuning on his truck. The problem has existed since the blower was installed and the mail order tune was put on the ECU. However, lately as we've been dialing in the boost (changing impellers), reducing torque management, changing timing and AFR, etc the issue has been coming up more and more. Since many of the MAF codes are turned off right now (they were being thrown left and right before) I suspect that the problem might very well be the P1514 or a similar table/code that isn't calibrated for part throttle boost, esp up a long hill. The granetelli also might be causing the issues....I usually don't hear great things from tuners about Granetelli's...they're more of a band-aid than anything. The funny thing is that we can hit it WOT for several shifts up to 90+mph and it usually won't throw the reduced power....but as soon as you go up a decent hill at part throttle for more than a few seconds....it goes right to that reduced power mode.

Once I look into that P1514 and turn the MAF codes back on, I'll report back with results. Thanks for all of your help!