The automatic transmission may develop shifting concerns. On lower mileage vehicles, upgrading the software in the powertrain control module (PCM) and the transmission control module (TCM) may correct the problem. As the mileage increases, internal transmission damage can occur. Repairs could involve replacement of the valve body or a complete transmission rebuild. Whenever major transmission repairs are made, it is important to be sure the PCM and the TCM have the latest software updates to help prevent these issues from reoccurring.Google+
Car Problem Reports
Lincoln MKZ Harsh or Delayed Shifting of Automatic Transmission
Lincoln MKZ Problem
Drive Trains Affected: AWD, FWD
Average Mileage: 106,200 mi (65,000 mi - 159,000 mi)
Visitor, 2007 Lincoln MKZ, FWD, 75,000 mi
Downshifting very hard! Valve body was replaced under extended warranty. Shifting normal now. At the same time my air conditioner started blowing one side hot one side cold.
Visitor, 2008 Lincoln MKZ, FWD, 159,000 mi
Problems shifting, especially when going up hill.
Although my car has 160,000 miles on it, it's been doing it for probably 30,000 miles.
Visitor, 2007 Lincoln MKZ, AWD, 130,000 mi
Harsh delayed shifting failure to shift into gear