P0300-12, P1313-14, P1316
MISFIREMonitoring Procedure
The engine is judged to be misfiring when the rate of crankshaft speed fluctuation is above a calibration level. If a single cylinder cannot be judged to be the cause of the misfire then a random misfire judgement is made.
If the misfire rate is sufficient to cause an emissions test failure then the misfire excess emissions failure is made. If this judgement is made in two successive trips under similar road and speed conditions the appropriate trouble code is stored.
If the misfire rate is high enough to cause catalyst damage the the catalyst damage trouble code is stored immediately.