B1372

Step 1: Locate the illuminated entry relay in the fuse/relay panel (typically under dash or in engine compartment). Visually inspect relay and socket for corrosion, bent pins, or damage. Remove relay and check for proper pin tension in socket.

Step 2: Using a digital multimeter, check for battery voltage on the relay power supply terminal with ignition on. Verify ground circuit continuity at the relay socket ground terminal (should be less than 1 ohm to chassis ground).

Step 3: Install a known-good relay or test the suspect relay using an ohmmeter to measure coil resistance (typically 70-120 ohms between control terminals). If relay tests good, backprobe the BCM connector control wire terminal while commanding relay on via scan tool active test; should see voltage switching from 0V to 12V.

Step 4: If no voltage switching occurs at BCM connector, inspect wiring harness between BCM and relay for opens, shorts, or damaged insulation. Check for continuity in control wire from BCM pin to relay socket with all connectors disconnected (should be less than 5 ohms).

Step 5: If all wiring and connections test good and relay functions properly when bench tested, suspect failed BCM internal relay driver. Verify BCM ground circuits are intact and clear any other BCM-related codes before condemning BCM.

Step 6: After repair, clear codes, cycle ignition, and perform functional test by unlocking doors and opening doors to verify illuminated entry lights activate properly. Re-scan for codes to confirm repair.