LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Cadillac >> 1999 >> DeVille Base >> Repair and Diagnosis >> Accessories & Equipment >> Memory Modules >> Memory System >> Memory Seat Module (MSM) Diagnostic Tests >> DTC B2111: Lumbar Down Switch Failed (Am3) >> Diagnostic Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

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. Connect scan tool to Data Link Connector (DLC). Disconnect left lumbar switch connector. Using scan tool, clear DTCs. After 30 seconds, check for DTCs. If DTC is reset, go to next step. If DTC is not reset, go to step  5 .
  3. Disconnect lumbar massage module connector. Using scan tool, clear DTCs. After 30 seconds, check for DTCs. If DTC is reset, go to next step. If DTC is not reset, go to step  6
  4. Check for short to ground in circuit Yellow wire between Memory Seat Module (MSM) connector C1 terminal No. 22 and lumbar massage module connector terminal "R". See WIRING DIAGRAMS  . If faulty circuit is found, go to step  9 . If circuit is okay, go to step  10 .
  5. Replace left seat lumbar switch. See POWER SEATS - DEVILLE & ELDORADO article. Recheck system operation. After repairs, go to step  11 .
  6. Check for short to ground in Yellow wire between lumbar massage module connector terminal "H" and left seat lumbar switch connector terminal "C" (DeVille) or "D" (Eldorado). If faulty circuit is found, go to next step. If circuit is okay, go to step  8 .
  7. Repair short to ground in Yellow wire between left seat lumbar switch and lumbar massage module. After repairs, go to step  11 .
  8. Replace left lumbar massage module. After repairs, go to step  11 .
  9. Repair short to ground in Yellow wire between MSM and lumbar massage module. After repairs, go to step  11 .
  10. Replace MSM. See MEMORY SEAT MODULE  under REMOVAL & INSTALLATION. After repairs, go to next step.
  11. 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.
scientia non olet · About LEMON Manuals