LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Cadillac >> 2001 >> DeVille Base >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Body Control Modules >> Diagnostic System Checks >> Defogger Diagnostic System Check
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Defogger Diagnostic System Check

  1. Connect a scan tool to Data Link Connector (DLC). If scan tool powers up, go to next step. If scan tool does not power up, go to TEST A: SCAN TOOL DOES NOT POWER UP  under SYSTEM TESTS.
  2. Turn ignition on. Try to establish communications with Instrument Panel Integration Module (IPM), Rear Integration Module (RIM). If scan tool communicates with IPM and RIM, go to next step. If scan tool does not communicate with IPM and RIM, see TEST B: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE  under SYSTEM TESTS.
  3. Access CLASS 2 POWER MODE in DIAGNOSTIC CIRCUIT CHECK on scan tool. Rotate ignition switch through all positions while observing ignition switch power mode parameter. If ignition switch parameter reading matches ignition switch position for all switch positions, go to next step. If ignition switch parameter reading does not match ignition switch position for all switch positions, go to step TEST C: POWER MODE MISMATCH  under SYSTEM TESTS.
  4. Select display DTCs function for IPM and RIM. If any DTCs are set for IPM or RIM, go to next step. If no DTCs are set for IPM or RIM, see REAR WINDOW & MIRROR DEFOGGERS - DEVILLE & SEVILLE article for further diagnosis.
  5. If scan tool does not display any DTCs that begin with a "U", go to next step. If scan tool displays any DTCs that begin with "U", see TEST B: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE  under SYSTEM TESTS.
  6. If scan tool does not display DTC B1004, B1007 or B1009, go to next step. If scan tool displays DTC B1004, B1007 or B1009, see DIAGNOSTIC TROUBLE CODE DEFINITIONS .
  7. If scan tool displays DTC B1327 or B1328, see DIAGNOSTIC TROUBLE CODE DEFINITIONS in GENERATORS & REGULATORS - DEVILLE article in STARTING & CHARGING SYSTEMS. If scan tool does not display DTC B1327 or B1328, see REAR WINDOW & MIRROR DEFOGGERS - DEVILLE & SEVILLE article for further diagnosis.
scientia non olet · About LEMON Manuals