LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Buick >> 2011 >> Lucerne CX >> Repair and Diagnosis >> External Pages >> Different car >> Section 249 (Lighting System) >> Diagnostic Information and Procedures >> DTC B2585 >> Circuit/System Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Testing

WARNING: This page is about a different car, the 2011 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, remove the appropriate PRK LAMP Relay or RT PRK LAMP relay from the rear fuse block.
  2. Connect a test lamp between B+ and the appropriate control circuit terminal listed below.
    • Control terminal 101
    • Control terminal 92 - Japan, Korea, Taiwan only
  3. Ignition ON, command the Parking Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
    • If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.
    • If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  4. If the circuit tests normal, test or replace the park lamp relay.