A Misfire induces a decrease in the engine speed and causes a variation in the segment period. Therefore, misfiring detection is based on the observation of this variation of the segment period.
Because of the tolerance in mechanical machining and assembling process of the target wheel, the duration of each segment are not always same but differ from segment to segment on the same engine. And this irregular segment duration can disturb misfiring detection which is based on the difference of engine rotational speed between the firing and the misfiring cylinder. The ECM compares segment duration of 4 cylinders during fuel cut-off and deceleration period. With this comparison ECM perform segment adaptation to adapt the difference of each segment duration.
The ECM sets DTC P0315 if any of segment adaptation value is on the limit.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Monitor segment time adaptation | ● Improperly installed target wheel ● Contact resistance in connectors |
Enable Conditions | ● 480 〈 Engine speed (RPM)〈 6,500 ● Intake air mass gradient is in predetermined range. ● No injection shut off. ● No rough road. | |
Threshold Value | ● Segment adaptation value = 5/1000 |
