Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Cadillac >> 1998 >> Seville STS >> Repair and Diagnosis >> Body & Frame >> Body, Cab Control Systems >> Body Control Module >> Diagnosis & Testing >> DTC B2422: Interior Light Rheostat Failure >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform BCM diagnostic system check. See BCM DIAGNOSTIC SYSTEM CHECK  . After performing system check, go to next step.
  2. Check if DTC B2420 is also set. If DTC B2420 is set, go to next step. If DTC B2420 is not set, go to step 6).
  3. Disconnect headlight switch harness connector. Disconnect IPM harness connector. Using a DVOM, connect DVOM between headlight switch harness connector terminal B3 (Yellow wire) and IPM harness connector C1 terminal B8 (Yellow wire). See WIRING DIAGRAMS  . If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, go to step 9).
  4. Disconnect IPM harness connector C2. Check resistance between ground and IPM harness connector terminal B12 (Light Blue/Black wire). If resistance is less than 5 ohms, go to step 10). If resistance is not less than 5 ohms, go to next step.
  5. Connect DVOM between headlight switch harness connector terminal No. B1 (Light Blue/Black wire) and IPM harness connector terminal B12 (Light Blue/Black wire). If resistance is less than 5 ohms, go to step 8). If resistance is not less than 5 ohms, go to step 11).
  6. Disconnect headlight switch harness connector. Disconnect IPM harness connector. Check resistance between headlight switch harness connector terminal B2 (Dark Green wire) and IPM harness connector terminal B11 (Dark Green wire). If resistance is less than 5 ohms, go to step 12). If resistance is not less than 5 ohms, go to next step.
  7. Check resistance between headlight switch harness connector terminal B2 (Dark Green wire) and IPM harness connector terminal B11 (Dark Green wire). If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, go to step 13).
  8. Replace headlight switch. After replacing switch, go to step 14).
  9. Repair open in Yellow wire between headlight switch and splice. After repairs, go to step 14).
  10. Repair short to ground in Light Blue/Black wire between IPM and headlight switch. After repairs, go to step 14).
  11. Repair open in Light Blue/Black wire between IPM and headlight switch. After repairs, go to step 14).
  12. Repair short to ground in Dark Green wire between IPM and headlight switch. After repairs, go to step 14).
  13. Repair open in Dark Green wire between IPM and headlight switch. After repairs, go to next step.
  14. Turn ignition off. Reconnect all components and connectors. Turn ignition on. Clear DTCs using scan tool. After clearing DTCs, perform BCM diagnostic system check. See BCM DIAGNOSTIC SYSTEM CHECK  .
scientia non olet · About Mike's Workshop Manuals