B0150

Code

Generic B — Body

Body Control Module Internal Fault

Brand: Generic

Type: B — Body

Views: UK: 20 EN: 33 RU: 17

AI status

Completed

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Page language: EN

Causes

Internal BCM hardware failure (failed IC, solder joint, PCB trace)
Corrupted BCM software/firmware
Intermittent or low battery voltage / poor power supply
Poor ground or high resistance in ground circuit
Corroded or damaged connectors or wiring to BCM
Moisture/water intrusion or physical damage to module

Symptoms

Multiple body systems inoperative or intermittent (door locks, interior lights, exterior lights, wipers, HVAC controls)
One or more modules show communication loss with BCM on diagnostic tool
Erratic operation of convenience features (random relays switching, incorrect lighting behavior)
Parasitic battery drain when vehicle is off
Warning lamps or message center errors related to body systems
Vehicle may not enter keyless/remote functions or fail to sleep properly

What to check

Read DTCs and freeze frame data with a capable scan tool and save reports
Verify battery state-of-charge and resting voltage (12.4–12.8 V typical); check battery terminals and cable condition
Inspect fuses and BCM power/ignition circuits for blown fuses or fusible links
Visually inspect BCM connectors and wiring harness for corrosion, bent pins, water intrusion or physical damage
Check chassis ground(s) and measure voltage drop during cranking and at rest
Attempt to communicate with BCM using scan tool; note any intermittent responses or timeouts

Signal parameters

BCM supply voltage: nominal ~12 V with ignition off/on (should remain stable within vehicle spec)
Ground voltage drop: chassis ground to battery negative should be low (
CAN/LIN bus communication: module should respond to diagnostic requests; CAN recessive voltage ~2.5 V per bus line and differential present (verify with scope or CAN tester)
Wake/sleep control signals: BCM should detect and generate wake/sleep messages on network and control lines
Quiescent current: BCM sleep current typically very low (microamp to low milliamp range) — unusually high values indicate internal fault
Internal self-test status: module may report FAIL states or internal error counters via diagnostics

Diagnostic algorithm

Retrieve all related DTCs and freeze frame; record module information (part number, software/calibration ID)
Verify vehicle battery SOC and charging system; restore full battery voltage and retest to rule out low-voltage artifacts
Inspect all BCM fuses, power feeds and ground connections; clean/repair/replace corroded connectors and retest communication
Measure BCM supply and ground at the module connector while monitoring for voltage drops, spikes or intermittent loss
Check CAN/LIN physical layer: measure bus voltages, verify termination resistances and continuity to other modules
If module communication is intermittent, wiggle-test harness (with battery disconnected as needed) and inspect for damaged wiring
Check for water intrusion or physical damage to the BCM housing; if present, repair wiring and consider module replacement
Verify latest software/firmware level and apply manufacturer updates or reflashes per service procedure; perform module reset/relearn if permitted
If all external circuits and software are verified good and fault remains, consider bench-testing/repair or replacing the BCM and program/configure with correct vehicle keys, VIN and options
After repair or replacement, clear DTCs and perform full system checks and road test to confirm resolution

Likely causes

Battery voltage drop or unstable supply to BCM (low battery, bad battery cables, weak alternator)
Poor or corroded ground at BCM chassis ground point
Connector corrosion, bent pins or water damage at BCM housing
Software/firmware corruption or failed module self-test
Age-related internal component failure on BCM PCB

Fault status

⚠️ Status

BCM internal fault detected. Module self-test failed or internal error reported; may cause multiple body system malfunctions or loss of network communication.

🔴 Repair difficulty: Hard

⏱️ Diagnostic time: 1.0-3.0 hours