Malibu V6-3.1L VIN J (2002)
EGR Valve: Description and Operation
LINEAR EGR VALVE
The linear EGR valve is designed to accurately supply EGR to an engine independent of intake manifold vacuum. The valve controls EGR flow from the
exhaust to the intake manifold through an orifice with a PCM controlled pintle. During operation, the PCM controls pintle position by monitoring the
EGR position sensor signal circuit. The signal circuit can be monitored with a scan tool as EGR position sensor. The EGR position sensor should always
be near the commanded EGR position (DESIRED EGR POS.). If a problem with the EGR system will not allow the PCM to control pintle position
properly, DTC P0404 should set. The PCM also tests for EGR flow. If an incorrect flow is detected, DTC P0401 should set. If DTCs P0401 and/or
P0404 are encountered.
The linear EGR valve is usually activated under the following conditions:
^
Warm engine operation
^
Above idle speed
