LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Chevrolet >> 2006 >> Impala SS >> Repair and Diagnosis >> External Pages >> Different car >> Section 249 (Lighting Systems) >> Diagnostic Information and Procedures >> DTC B2645 >> 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 2006 Buick Lucerne. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at the ambient light sensor.
  2. Ignition OFF, test for less than 5 ohms of resistance between the appropriate low reference circuit listed below and ground.
    • Terminal B with C67
    • Terminal C with CJ2
    • If greater than the specified range, test the low reference circuit for an open/high resistance.
  3. Ignition ON, verify the scan tool Ambient Light Sensor parameter is greater than 4.65 volts.
    • If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the BCM.
  4. Install a 3A fused jumper wire between the appropriate signal circuit and the low reference listed below. Verify the scan tool Ambient Light Sensor parameter is less than 0.196 volts.
    • Terminal A and terminal B with C67
    • Terminal D and terminal C with CJ2
    • If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  5. If all circuits test normal, test or replace the ambient light sensor.