B0287

Code

Generic B — Body

Body Control Module Communication Fault

Brand: Generic

Type: B — Body

Views: UK: 2 EN: 3 RU: 1

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Faulty or intermittent BCM (Body Control Module)
Open, shorted, or corroded wiring or connectors on the vehicle network (CAN/LIN)
Poor battery voltage or ground at the BCM
Blown fuse or loss of BCM power/ignition feed
Faulty or misconfigured gateway or other control module preventing messages
Network bus termination or impedance problem

Warning lights or message center alerts related to body systems
One or more body functions inoperative (door locks, lights, wipers, HVAC controls, etc.)
Intermittent operation of electrically controlled accessories
Multiple communication-related DTCs present (U-codes or other B-codes)
No communication with BCM when scanned with a diagnostic tool

Scan all modules; record freeze frame and all active/ stored codes
Verify battery voltage (12.4–12.9 V at rest, 13.5–14.8 V with engine running) and inspect ground connections
Check BCM power and ignition feeds and related fuses/relays
Visually inspect BCM connectors and wiring for corrosion, damage, or loose pins
Monitor the vehicle data bus with a scan tool to see if BCM messages are present
Check CAN bus termination resistance (about 60 ohms across CAN H and CAN L at key off)

CAN high (CAN H) idle ~2.5–3.5 V, CAN low (CAN L) idle ~1.5–2.5 V (differential ~0 V idle, up to ~2 V active)
Typical CAN speeds: 250 kbps or 500 kbps (verify vehicle-specific)
Network termination resistance ~60 ohms across CAN H and CAN L
LIN bus: single-wire signal 0–12 V pulses (if used on body network)
Battery supply to BCM: nominal 12 V (check for drop below ~9–10 V during cranking or loads)

Read and save all DTCs from all modules. Note time-stamped events and related U-codes.
Verify battery voltage and check primary grounds near BCM. Clean and tighten as needed.
Inspect BCM connectors for corrosion, bent pins, or water intrusion. Re-seat connectors.
Check fuses and relays feeding the BCM; replace any blown fuses and retest.
Using a capable scan tool, monitor the CAN/LIN messages to confirm whether the BCM transmits/receives messages. Note bus errors or bus-off states.
Measure CAN H and CAN L voltages at the BCM connector with key on, engine off. Compare to expected ranges.
Check termination resistance across CAN H and CAN L with power off. Replace missing resistors or repair wiring if out of range.
Perform continuity and short-to-power/ground tests on suspect wiring between BCM and other modules. Repair any faults.
If another module is causing bus errors, isolate by disconnecting modules one at a time (where safe) while monitoring the bus to identify the faulty device.
If wiring and other modules test good, attempt BCM software update or reflash per manufacturer procedures. If reprogramming fails to clear the fault, consider BCM replacement.
Clear codes and verify repair by road test and re-scan for recurrence.