Results 1 to 13 of 13

Thread: Reduced Engine Power Message

  1. #1
    Senior Tuner Jim P's Avatar
    Join Date
    Jan 2018
    Location
    Everywhere
    Posts
    1,457

    Reduced Engine Power Message

    So did a tune for a guy for a 2011 LML, all emissions off, CP3 conversion, getting the ?Reduced Engine Power? message even though the parameter for that is turned off. Other than that message, truck runs fine, no codes. Anyone got any insight as to possible cause?

  2. #2
    Advanced Tuner TheMechanic's Avatar
    Join Date
    Jan 2014
    Location
    SoCal
    Posts
    252
    Need a little more info. Did you scan and see what codes it is displaying? May be a "permanent". DEF issues have many permanent codes.

  3. #3
    Senior Tuner Jim P's Avatar
    Join Date
    Jan 2018
    Location
    Everywhere
    Posts
    1,457
    There are no codes being displayed, everything to do with the EGR, DPF, DEF and warnings is turned off via the disable switches in the ECM.
    Last edited by Jim P; 02-26-2021 at 09:01 AM.

  4. #4
    Advanced Tuner TheMechanic's Avatar
    Join Date
    Jan 2014
    Location
    SoCal
    Posts
    252
    Must be from a different module. Do you have an aftermarket scan tool that will display mode 10? Those are the permanent codes I was talking about. Permanent Diagnostic Trouble Codes (PDTCs) are very similar to regular Diagnostic Trouble Codes (DTCs). However, unlike regular DTCs, they cannot be reset by disconnecting the vehicle’s battery or cleared using an On-Board Diagnostic (OBD) scan tool. The only way to clear a PDTC is to fix the underlying problem with the vehicle that originally caused the PDTC and its corresponding DTC to set, and then allow the vehicle sufficient drive time to re-run the monitor that identified the problem in the first place. When the monitor runs without identifying a problem, the PDTC will clear itself. Most of the time they are DEF related.

  5. #5
    Senior Tuner Jim P's Avatar
    Join Date
    Jan 2018
    Location
    Everywhere
    Posts
    1,457
    I don?t have the truck, no where near it, would have to talk to the guy I did the tune for to see if he?s got anything to check that.

  6. #6
    Senior Tuner Jim P's Avatar
    Join Date
    Jan 2018
    Location
    Everywhere
    Posts
    1,457
    He?s going to check the next time the truck is brought in, if he remembers that is lol. The customer isn?t complaining about it though.

  7. #7
    You might check and clean MAF Sensor they mess up these trucks up ALL the time!! Not sure if you did this with HPT as I haven't done any with HPT. But with EFI I have had a similar problem with a message but it usually has emissions messages as well if it is in the tune. On some of the 11-12 trucks specifically I have ended up switching the main OS to 12644094 and the problem goes away and never comes back. But I know that's not really much of an option with HPT. Hope this helps.

  8. #8
    Senior Tuner Jim P's Avatar
    Join Date
    Jan 2018
    Location
    Everywhere
    Posts
    1,457
    Yes the tune was done with HPT. I don?t have the truck. Would be nice if you could change OS with HPT but they are too restrictive.

  9. #9
    Tuner in Training
    Join Date
    Jun 2015
    Posts
    38
    Wait since when did hpt enable the dtc list again??

  10. #10
    Senior Tuner Jim P's Avatar
    Join Date
    Jan 2018
    Location
    Everywhere
    Posts
    1,457
    No clue, never knew the dtc list was ever ever disabled.

  11. #11
    Senior Tuner Jim P's Avatar
    Join Date
    Jan 2018
    Location
    Everywhere
    Posts
    1,457
    So this message seems to be coming from when the egr gets unplugged. The engine doesn?t derate at all and runs hard, just displays the message once the egr gets unplugged, I have the bit toggled for the message to be shut off but still comes up, could it be possibly from the egr command tables not being zero?d out. That?s something I didn?t do in the tune.

  12. #12
    Tuner in Training
    Join Date
    Sep 2015
    Posts
    42
    just the dtc list will not delete a lml, you need lml xdf files
    Can provide files for most LBZ & LMM trucks on a diet

  13. #13
    Senior Tuner Jim P's Avatar
    Join Date
    Jan 2018
    Location
    Everywhere
    Posts
    1,457
    Quote Originally Posted by Bertus76 View Post
    just the dtc list will not delete a lml, you need lml xdf files
    Beyond aware of that and have what is needed. As stated, truck runs fine. It does not derate or anything, has plenty of power, only has that message. The truck owner wasn?t concerned over the message though.

    I believe the message is appearing from the egr tables not being zero?d out. It only appears as soon as the egr is unplugged.