LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2000 >> Suburban C2500 >> Repair and Diagnosis >> External Pages >> Different car >> Section 11 (Body Control Modules) >> Diagnostic Tests >> DTC B2648: Ambient Light Sensor Circuit High >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 1999 GMC Sierra and 1999 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
  1. If BCM diagnostic system check has been performed, go to next step. If BCM diagnostic system check has not been performed, perform BCM diagnostic system check. See BCM DIAGNOSTIC SYSTEM CHECK  under SYSTEM TESTS.
  2. Install scan tool. Monitor current DTCs. Disconnect ambient light sensor. If scan tool displays DTC B2648 as current, go to next step. If scan tool does not display DTC B2648 as current, go to step  4 .
  3. Disconnect Purple BCM connector C3. Using DVOM, measure voltage (backprobe) between Purple BCM connector C3 terminal A6 (White wire) and ground. See Figure . If reading is 5 volts or more, go to step  5 . If reading is less than 5 volts, go to step  6 .
  4. Replace ambient light sensor. After replacing ambient light sensor, go to step  7 .
  5. Repair short to battery voltage in White wire between ambient light sensor connector terminal "B" and Purple BCM connector C3 terminal A6. See WIRING DIAGRAMS  . After repairs, go to step  7 .
  6. Replace BCM and program. See BODY CONTROL MODULE (BCM)  under REMOVAL & INSTALLATION.
  7. Reconnect all components. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)  under SELF-DIAGNOSTIC SYSTEM.
scientia non olet · About LEMON Manuals