GM Service Manual Online
For 1990-2009 cars only
  1. Perform the Diagnostic System Check - Vehicle.
  2. Using a test lamp, test the Memory Seat Module (MSM) supply voltage circuit.
  3. If test lamp does not illuminate, repair or replace the supply voltage circuit.
  4. Using a DMM, test the MSM communications circuit for resistance.
  5. If greater than 5 ohms, repair or replace the circuits.
    If less than 5 ohms, refer to Body Control Module for further diagnosis.