Service Slants - MIL Illuminates on Start-up
I subscribe to a few automotive service trade magazines and they have some good information that you might find valuable. Here's a recent one concerning 2006 Grand Cherokees and Commanders with the 5.7L V8 engine:
Some 2006 Grand Cherokees and Commanders with the 5.7L V8 engine built prior to 09/08/05 may illuminate the MIL on initial start-up and log DTC P2112 (Electronic Throttle Control Unable To Open) in memory. Jeep says if there are no driveability symptoms when the light comes on, the code is probably bogus and due to software issues in the PCM. The only way to correct this issue is to reflash the PCM with the updated calibration. The updated flash files are available via the Internet or off the StarSCAN update CD version 6.03 or later.