P1408 Buick EGR Flow Out Of Self Test Range

P1409 Buick EVR Control Circuit Malfunction

Possible causes
  • EGRVR circuit open.
  • VPWR open to EGRVR solenoid.
  • EGRVR circuit short to VPWR or GND.
  • Damaged EGRVR solenoid.
  • Damaged PCM.
    • Tech description
    The EGR vacuum regulator solenoid resistance is between 26 and 40 ohms.
    Symptoms
    – Engine Light ON (or Service Engine Soon Warning Light)
    P1409 Buick Description

    This test checks the electrical function of the EGRVR solenoid. The test fails when the EGRVR circuit voltage is either too high or too low when compared to the expected voltage range. The EGR system must be enabled for the test to be completed.

    Buick Vehicle:Buick Regal – ?Buick Riviera – ?Buick LaCrosse – ?David Dunbar Buick – Buick Century – Buick LaCrosse – Buick LeSabre – Buick Lucerne – Buick Park Avenue – Buick Regal – Buick Verano – Buick Enclave – Buick Encore – Buick Rainier – Buick Rendezvous – Buick Terraza – Buick Riviera