Time Needed for Diagnosis:0 ms + 3000 ms + 10000 ms + 10000 ms + 25000 ms
Mode C: (Check pressure rise)
Stop the introduction of negative pressure. (Wait until the tank pressure returns to the start level of P2 calculation.)
Change to Mode D when the tank pressure returns to the start level of P2 calculation. Judge immediate OK and change to Mode E when it
does not return in spite of spending the specified time.
Time Needed for Diagnosis: 0 ms + 3000 ms + 10000 ms + 10000 ms + 25000 ms + 18600 ms
Mode D: (Measure amount of negative pressure change)
Monitor the tank pressure change amount when using mode D. In this case, the tank pressure increases, (nears barometric pressure) because
evaporation occurs. However, if any leakage exists, the pressure increases additionally in proportion to this leakage. The pressure variation of
this tank is P2.
After calculating P2, perform a small leak diagnosis according to the items below.
When Mode D is ended
Assign tank variations measured in Mode A and Mode D, P1 and P2, to the formula below, judge small leaks in the system. If the measured
judgment value exceeds the threshold value, it is judged to be a malfunction.
Abnormality Judgment
Judge as NG when the following conditions are established within the predetermined time. Judge as OK and clear the NG if the following
conditions are not established within the predetermined time.
Map 5 Malfunction criteria limit for evaporation diagnosis
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