Results 1 to 3 of 3

Thread: 545RFE stuck in limp mode after flashing

  1. #1
    Tuner in Training
    Join Date
    Jun 2019
    Posts
    37

    545RFE stuck in limp mode after flashing

    I have a 2007 Chrysler Aspen 5.7 hemi. Around the time I started tuning it, it would occasionally get stuck in limp mode. It will stay in 3 or 4 (I'm not sure which) and I can only get 2nd if I shift manually with the column shifter. It seems to happen after flashing a tune and will sometimes go away if I revert to a previous tune or stock tune, but sometimes it still does it. It reports -3F trans fluid temp, so I jumped the wire directly from the PCM for the trans temp sensor with a resistor to simulate 190F. When it works normally, the trans temp reports 190-191F as it should, but sometimes it goes to limp mode and still reports -3 F trans fluid temp. I have tried setting all trans settings back to stock and it didn't seem to help. Any advice would be appreciated. Current tune and log. AspenCustomV7.hptAspenCustomV7v1.hpl

  2. #2
    Tuner in Training
    Join Date
    Jun 2019
    Posts
    37
    Update: I tried disconnecting the battery for a few minutes to clear any codes I couldn't see when it goes to limp mode. It seems to work the first time after reconnecting the battery, but after that it might do it again on the 2nd or 3rd ignition cycle. The vehicle sits a lot, so I think it may have to do with low voltage. I raised the desired alternator voltage about .5 volts and it seems to have helped. Control Module Voltage at 86 deg ambient temp went from 13.80 to 14.10 which is where my challenger likes to be also.

  3. #3
    Advanced Tuner PurpleRam's Avatar
    Join Date
    Aug 2017
    Location
    Quakertown PA
    Posts
    478
    Quote Originally Posted by Iceyrider View Post
    Update: I tried disconnecting the battery for a few minutes to clear any codes I couldn't see when it goes to limp mode. It seems to work the first time after reconnecting the battery, but after that it might do it again on the 2nd or 3rd ignition cycle. The vehicle sits a lot, so I think it may have to do with low voltage. I raised the desired alternator voltage about .5 volts and it seems to have helped. Control Module Voltage at 86 deg ambient temp went from 13.80 to 14.10 which is where my challenger likes to be also.
    thanks for the update
    04 GTX........ 8.91@151mph 392Ci G3Hemi NA 3600lbs 2.6HP/CI Naturally Aspirated
    05 GTxtreme 9:45@142mph 426Ci G3Hemi NA 4000lbs
    G3 Hemi Videos

    https://www.youtube.com/channel/UClS...5mXdDR5sOxs10Q