(Use this only if you still have issues after our BCM service)
Step 1 – Confirm BCM power & grounds
-
Battery 12.4–12.7V KOEO; 13.5–14.5V running
-
Check all BCM/IGN/ROOM/LAMP fuses (dash and under-hood) with a test light
-
Inspect BCM connectors for bent pins, corrosion, loose fit, or water traces
-
Verify body/engine grounds are clean and tight
Step 2 – If you still have U0140 / U1000 (no communication / network issues)
-
Confirm scan tool is set to correct year/model and protocol
-
Wiggle BCM harness while watching live data for dropouts
-
Inspect CAN wires (twisted pair) near BCM and in kick panels for damage or aftermarket splices
-
Remove or temporarily disable any aftermarket alarm/remote start and retest
Step 3 – If locks or hatch still operate by themselves
-
Check door-lock and hatch switch buttons for sticking; unplug suspect switches and see if symptom stops
-
Inspect driver door jamb and liftgate rubber boots for broken or shorted lock wires
-
Verify no remote key fob is stuck, wet, or stored where buttons can be pressed
-
Disconnect any added modules tied into lock/hatch wiring (remote start, add-on alarm)
Step 4 – If you have security/no-start (B2190–B2192 or key light on)
-
Use a capable scan tool to confirm key ID is registered in BCM/NATS
-
If ECM, IPDM, or keys were replaced, have a Nissan-capable tool perform key/ID re-registration
-
Check antenna ring and wiring around the ignition switch for damage or loose connections
Step 5 – If battery is still draining overnight
-
With everything off and doors closed, check parasitic draw with an ammeter
-
Pull BCM-related fuses one at a time; note which circuit drops the draw
-
Look for courtesy lights, hatch switch, or aftermarket equipment staying on or waking the BCM
-
Repair any circuit that keeps current above factory spec before condemning the BCM
Step 6 – When to look beyond the BCM
-
If power, grounds, wiring, switches, and add-on equipment all check good but symptoms remain, the root cause is likely elsewhere in the vehicle (locks, latch, wiring harness, or other modules).
-
At that point we recommend a full in-vehicle diagnosis by a technician who can load-test circuits and scope CAN signals.

