Electronic Control System: Self-Diagnosis

WARNING: This page is about a different car, the 2011 Honda Pilot, 2010 Honda Pilot, and 2009 Honda Pilot. However, it is still accessible from the selected car via links, so may be relevant.

The PCM detects a failure of a signal from a sensor or from another control unit and stores a pending DTC or a Confirmed DTC. Depending on the failure, a Confirmed DTC is stored in either the first or the second drive cycle. When a Confirmed DTC is stored, the PCM turns on the malfunction indicator lamp (MIL) by a signal sent to the gauge via F-CAN.

One Drive Cycle Detection Method
When an abnormality occurs in the signal from a sensor or from another control unit, the PCM stores a DTC and turns on the MIL immediately.
Two Drive Cycle Detection Method

When an abnormality occurs in the signal from a sensor or from another control unit in the first drive cycle, the PCM stores a Pending DTC. The MIL does not come on at this time. If the failure continues in the second drive cycle, the PCM stores a DTC and turns on the MIL.