Some 2010-2011 Ford Taurus and Flex, and Lincoln MKS and MKT vehicles equipped with a 3.5L GTDI (gasoline turbocharged direct injected) engine may exhibit rough running, hesitation or shuddering, with DTCs P0300, P0301, P0302, P0304, P0305, P0306 or P0316.
1. If the vehicle history indicates, or it can be otherwise confirmed, that the spark plugs have previously been replaced and no DTCs are present, but driveability concerns are present, proceed to Step 6.
2. Determine the engine build date. Refer to Workshop manual Section 303-01.
a. If the engine build date is on or before 8-2-10, proceed to Step 3.
b. If the engine build date is after 8-2-10, proceed to Step 6.
3. Retrieve DTCs to determine which cylinder has misfired.
4. Remove the spark plug of the affected cylinder.
5. Check the spark plug for broken ceramic.
a. If the spark plug features broken ceramic, or if the spark plug part number is CYFS-12F-3, replace all six spark plugs.
b. If the spark plug does not feature broken ceramic and the part number is CYFS-12Y-3, do not replace the spark plugs and proceed to Step 6.
6. Determine the vehicle build date.
a. If the vehicle build date is on or before 10-27-10, proceed to Step 7.
b. If the vehicle build date is after 10-27-10, do not continue with this bulletin, and refer to Powertrain Control/Emissions Diagnosis (PC/ED) manual for normal diagnosis.
7. Reprogram the Powertrain Control Module (PCM) to the latest calibration using IDS release 72.03 and higher. This new calibration is not included in the VCM 2011.3 DVD. Calibration files may also be obtained at www.motorcraft.com.
