| 摘要 |
PROBLEM TO BE SOLVED: To diagnose the failure of an exhaust circulating device with a high precision without deteriorating operability and exhausting performance. SOLUTION: When EGR is OFF while cutting fuel in deceleration (S2), cylinder internal pressure data PIFC1 is determined from a cylinder internal pressure sensor 11 (S4). Thereafter, EGR is forcedly ON (S5), and cylinder internal pressure data PIFC2 at that time is determined (S7). The presence of a failure of an EGR device is diagnosed (S10) on the basis of Δ PIFC (PIFC2-PIFCI). Since the failure of the EGR device is diagnosed in the state where no combustion is performed, the failure diagnosis can be performed with a high precision without deteriorating the operability and exhausting performance. |
