FixVault
Home › Cadillac › 1998 › Catera › Repair and Diagnosis › Body & Frame › Seats › Power Seat System › Self-Diagnostics › Scan Tool Does Not Communicate With Memory Seat Module (MSM)

Scan Tool Does Not Communicate With Memory Seat Module (MSM)

  1. If a second vehicle of the same make, model and year is available, connect scan tool to second vehicle. Attempt to establish communications with second vehicle. If scan tool communicates with second vehicle, go to step 3). If scan tool will not communicate with second vehicle, go to next step.
  2. If scan tool operates properly, go to next step. If scan tool does not operate properly, see scan tool user's manual.
  3. Disconnect driver's seat adjuster memory module connector C1. Use DVOM to measure resistance between memory module connector C1 terminal No. 6 and DLC connector terminal No. 7 (Brown/White wire). If reading is 5 ohms or less, go to step 5). If reading is greater than 5 ohms, go to next step.
  4. Repair open or short in Brown/White wire between memory module connector C1 terminal No. 6 and DLC connector terminal No. 7. After repair is complete, go to step 22).
  5. Use DVOM to measure resistance between ground and DLC connector terminal No. 7. If reading is 5 ohms or less, go to next step. If reading is greater than 5 ohms, go to step 13).
  6. Disconnect Engine Control Module (ECM). Use DVOM to measure resistance between ground and DLC connector terminal No. 7. If reading is 5 ohms or less, go to step 8). If reading is greater than 5 ohms, go to next step.
  7. Replace the ECM. See ENGINE CONTROL MODULE (ECM)  under REMOVAL & INSTALLATION. Go to step 22).
  8. Disconnect the instrument panel cluster. Use DVOM to measure resistance between ground and DLC connector terminal No. 7. If reading is 5 ohms or less, go to step 10). If reading is greater than 5 ohms, go to next step.
  9. Replace the instrument panel cluster. See INSTRUMENT PANELS - ANALOG article. Go to step 22).
  10. Disconnect the Transmission Control Module (TCM). Use DVOM to measure resistance between ground and DLC connector terminal No. 7. If reading is 5 ohms or less, go to step 12). If reading is greater than 5 ohms, go to next step.
  11. Replace the TCM. See TRANSMISSION CONTROL MODULE (TCM)  under REMOVAL & INSTALLATION. Go to step 22).
  12. If instrument panel cluster and all control modules are disconnected and short to ground still exists, repair short to ground in suspect circuit. See WIRING DIAGRAMS  . Go to step 22).
  13. Use DVOM to measure voltage between ground and DLC connector terminal No. 7. If battery voltage is indicated, go to next step. If battery voltage is not indicated, go to step 21).
  14. Disconnect Engine Control Module (ECM). Use DVOM to measure voltage between ground and DLC connector terminal No. 7. If battery voltage is indicated, go to next step. If battery voltage is not indicated, go to step 16).
  15. Replace the ECM. See ENGINE CONTROL MODULE  under REMOVAL & INSTALLATION. Go to step 22).
  16. Disconnect the instrument panel cluster. Use DVOM to measure voltage between ground and DLC connector terminal No. 7. If battery voltage is indicated, go to next step. If battery voltage is not indicated, go to step 19).
  17. Replace the instrument panel cluster. See appropriate INSTRUMENT PANELS - ANALOG article. Go to step 22).
  18. Disconnect the Transmission Control Module (TCM). Use DVOM to measure voltage between ground and DLC connector terminal No. 7. If battery voltage is indicated, go to next step. If battery voltage is not indicated, go to step 20).
  19. If instrument panel cluster and all control modules are disconnected and short to ground still exists, repair short to ground in suspect circuit. See WIRING DIAGRAMS  . Go to step 22).
  20. Replace the TCM. See TRANSMISSION CONTROL MODULE (TCM)  under REMOVAL & INSTALLATION. Go to step 22).
  21. Use DVOM to measure voltage and ground circuits for the adjuster memory module. If all circuits are okay, replace the driver seat adjuster memory module. See MEMORY MODULE  under REMOVAL & INSTALLATION. Go to next step.
  22. Reattach all connectors to all modules and the instrument panel cluster. Connect scan tool to DLC connector. If scan tool communicates with driver seat adjuster memory module, repair is complete. If scan tool does not communicate with driver seat adjuster memory module, go to step 1).
About FixVault