One problem related to ignition module has been reported for the 2012 Jeep Grand Cherokee. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 Jeep Grand Cherokee based on all problems reported for the 2012 Grand Cherokee.
While driving to work one day, I noticed a humming noise coming from the front of the vehicle, shortly before arriving at work the battery light came on so I dropped off the car at a local mechanic to have it looked at. They called me back to say the alternator had went out and would need replaced. After replacing the alternator, my Jeep wasn't starting, so they had to replace the battery and explained the alternator had fried and took the battery out with it. Once the battery was replaced, the Jeep still wouldn't start and couldn't locate the keys (although it was physically in the ignition), they said my Jeep would need to be towed to a Jeep dealership to get the powertrain control module replaced because they couldn't program the replacement module. After getting it towed and having the powertrain control module replaced it is running fine again. In summary, the alternator went out and shorted both the battery and the powertrain control module in the process. In total nearly $1600 worth of parts and labor. A recall exists for several other Jeep models due to this same issue, however my vehicle's VIN isn't listed in the recall.