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Home >> Cadillac >> 1999 >> DeVille Base >> Repair and Diagnosis >> Body & Frame >> Seats >> Memory System >> Memory Seat Module (MSM) Diagnostic Tests >> DTC B1656: EEPROM Write Error & DTC B1658: EEPROM Checksum Error >> Diagnostic Procedure
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Diagnostic Procedure

  1. If power seats system check was performed, go to next step. If power seats system check was not performed, go to SYSTEM CHECKS under TROUBLE SHOOTING in POWER SEATS - DEVILLE & ELDORADO article.
  2. Turn ignition on. Clear any DTCs. Turn ignition off and back on again. Recheck for DTCs. If DTC B1656 or B1658 is still present, go to next step. If DTC is no longer present, go to power seats system check.
  3. Replace MSM. See MEMORY SEAT MODULE  under REMOVAL & INSTALLATION. After repairs, go to next step.
  4. Turn ignition off. Reconnect all disconnected components and connectors. Turn ignition on and clear DTCs. If DTC is no longer present, go to power seats system check.
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