FixVault
Home
›
Buick
›
2003
›
Century Base
›
Repair and Diagnosis
›
Engine Performance
›
System
›
Engine Controls Self-Diagnostics - 3.1L Engine
›
Diagnostic Tests
›
DTC P1404: EGR Closed Position Performance
›
Conditions For Running Test
Conditions For Running Test
The engine is running.
The Ignition 1 Signal voltage parameter is 11-18 volts.
The EGR valve is commanded to zero percent for 20 seconds after the EGR valve has been commanded to open more than 40 percent for 0.5 second.