P1407 Code: Meaning, Causes, and Symptoms | OBD2 Codes

P1407 – Exhaust Gas Recirculation Flow Out Of Self-Test Range

 

P1407 Possible Symptoms

 

Engine Light ON (or Service Engine Soon Warning Light)

 

P1407 Possible Causes

 

Faulty Exhaust Gas Recirculation (EGR) Valve,Exhaust Gas Recirculation (EGR) Valve Vacuum hose off or defective,Plugged Exhaust Gas Recirculation (EGR) Valve

 

P1407 Description

 

The Exhaust Gas Recirculation (EGR) system recirculates a portion of the exhaust gasses into the intake manifold under average vehicle driving conditions to reduce combustion temperatures and exhaust gas NOx content. The amount of exhaust gas recirculated varies from zero with a cold engine to a fixed rate for a hot engine with intermediate load and low engine speed. This test is performed during the Key On Engine Running (KOER) on demand self-test only. The EGR system is commanded ON at a fixed engine speed. The test fails and the Diagnostic Trouble Code (DTC) is output when the measured EGR flow falls above or below the required calibration.