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ECM failure PT Cruiser

Discussion in 'Repairs, Maintenance, Help' started by jdrive, Nov 16, 2017.

  1. jdrive

    jdrive Member

    Nov 16, 2017
    My 2005 PT Cruiser throws the codes U0101 and P1603. Frequently it will not shift out of 1st gear when i start it or maybe shut it off at the gas station. I can reset the codes and sometimes the trans shifts great. Recently it wouldn't reset and remained in 1st only. Not good! I've decided the ECM needs to be replaced and would like to know if anyone has experience with a computer repair business.
  2. valiant67

    valiant67 Rich Corinthian Leather
    Level III Supporter

    Jan 7, 2003
    There are rebuilders like on eBay that will sell you a computer programmed with your VIN and mileage with a lifetime warranty. I’ve used one for my 99 Dakota and my 07 Magnum.
    ImperialCrown likes this.
  3. ImperialCrown

    Level III Supporter

    Jun 8, 2008
    Welcome to Allpar. Both the U0101 and P1603 faults can be caused from an interrupted ignition switch off/run/start voltage to the module. Diagnose this first. This can be intermittent, but it must be verified before condemning the ECM/PCM. Watch the PCI bus. See p. 263 and 285 here:
    If the PCM is considered to be defective because of P1603, then it will need configuring and replacement. The part # should be on a label affixed to the PCM housing. That # may have superseded to a later part #.
    The default (limp-in) transaxle gear is 2nd.
    If you have an anti-theft SKIM key, that 4-digit ID will also have to be entered. The PCM will run OK without the VIN and the dash will display the correct mileage without the odometer reading entered, but while the tool is connected, both might as well be entered while connected.
    If your vehicle does not have the factory VTS security system, do not install a PCM that has the VTS enabled. This will cause problems.
    Mopar has gotten away from 'remanufactured' modules and a blank, generic PCM is available. The dealer will download the software, configure and initialize the module.
    Used or aftermarket modules are a risk, some are OK and some are not. Lots of intermittent modules get stuck in a revolving door from parts shelf, to customer, to being rechecked as OK and then put back on the parts shelf. It can be frustrating and you get to try another used/reman PCM. This is one reason why Mopar got away from them. I can't recommend an online vendor as I have never used one. The generic PCM replacement is on this bulletin going forward. You are getting a brand new PCM. Your part # may be different than what is on the bulletin:
    TSB 18-007-03 D (at http://dodgeram.info/tsb/2003/18-007-03.htm )
  4. chuzz

    chuzz Well-Known Member

    Apr 3, 2004

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