| 摘要 |
PROBLEM TO BE SOLVED: To enable accurate diagnosis at technical expense as low as possible concerning functional property by forming and memorizing a control coefficient even when AGR is shut off as well as when AGR is charged, forming a difference in control coefficients, and comparing it with a predetermined limit value. SOLUTION: At first, wait time must elapse (120), before an average value of λ control deviation is formed in the formation of an average value of a control coefficient in exhaust gas recirculation (AGR) operation (13D). After the wait time elapses (150), the formation of average λ control coefficient when AGR operation is shut off is done (160). The λ control coefficient when AGR is shut off is memorized (170). A difference in the control coefficients when AGR is charged and shut off is formed (180), and is compared with a predetermined threshold value to judge whether the deviation is positive or negative (190, 195). When there is the deviation, an error of AGR is output (205). |
