Fail-safe Chart

WARNING: This page is about a different car, the 2004 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.

The ECM enters fail-safe mode, if any of the following malfunctions is detected. When the ECM enters the fail-safe mode, the MIL illuminates.

Fig 1: Fail-Safe Chart (1 Of 2)

Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 2: Fail-Safe Chart (2 Of 2)

Courtesy of NISSAN MOTOR CO., U.S.A.

When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting MIL up when there is malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected as NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by means of operating fail-safe function.

The fail-safe function also operates when above diagnoses except MIL circuit are detected, and demands the driver to repair the malfunction.

Fig 3: Fail-Safe Function Chart
Courtesy of NISSAN MOTOR CO., U.S.A.