B10E4

Code

Generic B — Body

Body Control Module Internal Fault

Brand: Generic

Type: B — Body

Views: UK: 7 EN: 14 RU: 4

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Temporary software glitch or corrupted module memory
Low or unstable battery voltage/power supply to BCM
Corroded, loose, or damaged power/ground connections or fuses
Faulty BCM hardware (internal electronics failure)
Water intrusion or physical damage to the BCM
CAN bus or LIN bus communication errors affecting module self-tests

Symptoms

Illuminated dash warning light (BCM or general electronic fault)
Intermittent or total loss of body functions (lights, locks, wipers, windows)
Modules report communication errors on scan tool (lost comms)
Random or persistent DTCs related to multiple body systems
Lighting flicker, door lock failure, or ignition accessory anomalies

What to check

Retrieve all stored codes and freeze-frame data from BCM and related modules
Check battery voltage (resting and with key on) and battery health
Inspect BCM fuses, fusible links, and related power distribution points
Visually inspect BCM connectors and harness for corrosion, bent pins, or water ingress
Scan the vehicle network for communication errors (CAN/LIN) and related U-codes
Verify ground connections for BCM chassis/engine ground points

Signal parameters

BCM supply voltage (should be ~12.0–14.5 V key on)
Battery voltage during cranking and load tests
CAN high/low voltages and differential (idle bus values, typically ~2.5 V +/-)
Module awake/asleep state and wake request counts
Current draw from BCM circuit (parasitic drain check)
Last internal self-test / error counters reported by BCM

Diagnostic algorithm

Record the exact DTC, freeze-frame data, and any related codes from all modules. Note when the code sets (startup, driving, after sleep).
Verify battery state-of-charge and charging system. Recharge or replace battery if voltage is low; retest.
Inspect and test all fuses and fusible links supplying the BCM. Replace any blown fuses and retest for recurrence.
Visually inspect BCM connector(s) and wiring for corrosion, damage, or water intrusion. Unplug connector and inspect pins; clean if necessary.
Verify solid grounds to the BCM with a low-resistance test to chassis/engine ground. Repair any high-resistance ground connections.
Use a scan tool to observe BCM parameters: supply voltage, wake/sleep state, CAN bus status, and internal fault counters. Check for other modules showing communication faults (U-codes).
Test CAN/LIN network continuity and for shorts to power or ground if communication errors are present. Repair wiring as required.
Attempt to clear the code and perform a controlled drive cycle or sleep/wake cycle to see if the code returns. Note recurrence pattern.
If intermittent, check for electrical noise sources or aftermarket devices that may interfere with the network; remove or isolate them.
If wiring, power and grounds are verified good and communications are normal but the fault persists, consult OEM service information for recommended BCM reprogramming or calibration. Perform software update or reflash per manufacturer procedure.
Only after confirming wiring, power/ground, and software are correct, consider BCM replacement. Follow manufacturer instructions for module coding/initialization and perform post-replacement system relearn procedures.
After repair or replacement, verify all body systems for correct operation and re-scan to confirm no additional codes are present.

Likely causes

Weak battery or poor battery terminal connections causing undervoltage
Blown fuse or fusible link feeding the BCM
Corroded connector pins or water-damaged BCM housing
Failed BCM internal electronics requiring replacement or reflash
Loss of CAN/LIN bus communication from a short/open on network wiring

Fault status

⚠️ Status

Body Control Module internal fault — module reported self-diagnostic error. Verify power, ground, communications, and module integrity before replacement.

🔴 Repair difficulty: Hard

⏱️ Diagnostic time: 1.0-3.0 hours