Some vehicles may exhibit a MIL on with DTC(s) P1285, P1299 and/or P0128. Engine temperature may be cold and report as hot or be hot and report as cold. Engine cooling fan operation may also be affected by the incorrect cylinder head temperature (CHT) sensor reading - turning on or off at inappropriate times.
These vehicles may also exhibit rough run, lack of power, MIL on with DTCs P0300, P0301, P0302, P0303, P0304, and/or P0316.