B1323

Step 1: Perform visual inspection of the instrument cluster door ajar lamp. With ignition on and a door open, verify if the lamp illuminates at all or shows abnormal behavior (flickering, dim, stuck on). Check for any visible damage to the cluster face or warning lights.

Step 2: Using a digital multimeter, backprobe the door ajar lamp circuit at the instrument cluster connector while the BCM commands the lamp on (door open condition). Verify voltage presence (typically 12V or BCM-controlled ground depending on circuit design) and compare to manufacturer specifications.

Step 3: Inspect both the BCM and instrument cluster connectors for corrosion, pushed-back pins, or physical damage. Check continuity of the door ajar lamp circuit wire from BCM to instrument cluster with ignition off, checking for opens (infinite resistance) or shorts to ground/power (near-zero resistance where it shouldn't be).

Step 4: If wiring and connections are intact, use scan tool bidirectional controls to command the door ajar lamp on and off while monitoring BCM data. If BCM shows proper command output but lamp doesn't respond and circuit has power/ground, suspect instrument cluster internal failure. If BCM cannot command the circuit, suspect BCM internal driver failure.

Step 5: After repair, clear codes and cycle all doors open and closed multiple times while monitoring the door ajar lamp operation. Verify the lamp illuminates when any door is open and extinguishes when all doors are closed. Road test and verify no code return.