B10FC

Code

Generic B — Body

Body Control Module (BCM) Internal Fault

Brand: Generic

Type: B — Body

Views: UK: 12 EN: 16 RU: 13

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Corrupted BCM firmware or software
Failed internal memory (EEPROM/FLASH) or processor fault
Power surge or voltage extremes (battery disconnect or jump start damage)
Water intrusion or physical damage to the BCM
Failed CAN/LIN transceiver internal to the BCM
Poor power or ground connections to the BCM

Symptoms

Multiple body systems malfunctioning (lighting, locks, wipers, etc.)
Intermittent or permanent loss of communication with BCM on scan tool
Related warning lamps or messages in cluster
Remote keyfob, central locking, or alarm not working
Functions operated by BCM behave erratically or are nonfunctional
Possible no-crank or immobilizer-related starting problems (depending on vehicle)

What to check

Read all stored codes and freeze frame data from BCM and network modules with a capable scan tool
Verify battery state-of-charge and system voltage (engine off and cranking)
Inspect BCM connectors and wiring for corrosion, pin damage, or moisture
Check power and ground pins at the BCM for proper voltage and continuity
Scan CAN/LIN bus for communication errors and active bus loads/terminations
Look for related codes in other modules (U-codes or body bus codes)

Signal parameters

Battery supply voltage (VBATT) at BCM pins (nominal ~12V)
Ignition/switched voltage (IGN) to BCM
Ground continuity and voltage drop on ground circuit
CAN high/low bus voltage levels and differential signal activity
LIN bus signal levels if applicable
Internal watchdog/error counters (where available in module data)

Diagnostic algorithm

Use a manufacturer-level scan tool to read BCM codes, freeze frame, and any pending or history entries; record details.
Verify battery voltage and health. Charge or replace battery if low and clear codes; re-check.
Visually inspect BCM and harness for water intrusion, damage, corrosion, or bent pins; repair as needed.
With ignition on, measure VBATT and IGN voltages at the BCM connector and check ground resistance. Repair poor power/ground connections.
Check vehicle network: verify CAN/LIN bus physical layer (voltage levels, dominant/recessive states) and for other modules reporting errors.
If communication is intermittent or absent, wiggle test wiring harness while monitoring bus activity to detect intermittent faults.
If wiring and supply are good, attempt soft reset/cycle power to BCM and re-scan. Some faults clear after proper power cycle.
Check for available TSBs or module software updates. If a corrupted software is suspected, perform a manufacturer-approved reflash/repair procedure.
If reflash fails or internal hardware fault persists, follow manufacturer procedure for module replacement and immobilizer/programming/parameterization. Ensure all modules are programmed and configured per spec.
After repair/reprogramming, clear codes and verify proper operation over a road test and through full system checks.

Likely causes

Corrupted or incomplete module reflash/update
Loss of battery power during programming
Internal hardware failure (processor, memory, transceiver)
Intermittent low battery/voltage causing internal watchdog faults
Connector corrosion or damaged wiring supplying Vbatt/ground

Fault status

⚠️ Status

BCM reported an internal integrity/error condition. The module logged an internal fault that may impact body functions or network communications. Further diagnostics required to identify whether the issue is software, supply/ground, wiring, or internal hardware failure.

🔴 Repair difficulty: Hard

⏱️ Diagnostic time: 1-4 hours