P1408 Mercury EGR Flow Out Of Self Test Range

Possible causes

For vacuum activated systems, see the possible causes for DTC P0401 Mercury. For electric motor systems, see the possible causes for DTC P0400 Mercury.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P1408 Mercury Description

This test is performed during the KOER on-demand self-test only. The EGR system is commanded on at a fixed engine speed. The test fails and the DTC is output when the measured EGR flow falls above or below the required calibration .