B0415

Code

Generic B — Body

Body Control Module Fault

Brand: Generic

Type: B — Body

Views: UK: 14 EN: 41 RU: 18

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

BCM internal hardware or software failure
Low battery voltage or poor battery connection
Corroded, loose or damaged BCM power/ground connections
Faulty or shorted wiring to sensors, switches or actuators
CAN/LIN bus communication errors or bus short
Water intrusion or physical damage to BCM or connector

Symptoms

Multiple body functions inoperative (lights, locks, wipers, etc.)
Intermittent or permanent loss of remote/keyless functions
Warning lamp(s) or message about module failure
Vehicle no-crank/no-start in some designs or abnormal starter behavior
Unexplained battery drain when vehicle off
Erratic behavior of interior lighting, HVAC controls or door sensors

What to check

Read all stored codes and freeze frame data from all modules; note related U and B codes
Verify battery state-of-charge and cranking voltage (nominal ~12.6 V; may dip during cranking)
Inspect BCM fuses, relays and fuseholder contacts for continuity and corrosion
Visually inspect BCM connector(s) for bent pins, corrosion, water ingress or damage
Check main BCM power and ground circuit continuity and voltage at the module
Scan CAN/LIN bus status and check for other module communication errors

Signal parameters

BCM supply voltage: nominal ≈12 V (verify 11–14 V under normal conditions; may go lower during crank)
Ground continuity: near 0 ohms between BCM ground pins and chassis
CAN bus voltages: CAN High ≈2.5–3.5 V, CAN Low ≈1.5–2.5 V idle differential ≈0 V; differential ≈2 V during data
LIN bus idle: typically near battery voltage through pull-up (varies by vehicle)
Module wake/sleep control signals present when ignition is ON or wake event occurs
Communication packets present on bus when scanning (no timeouts or excessive errors)

Diagnostic algorithm

Connect a professional scan tool and record all BCM and network codes, freeze frame and live data.
Verify battery voltage and charging system; charge battery if low and retest.
Inspect BCM area and connectors for corrosion, moisture, or physical damage; repair/clean as needed.
Check fuses/relays feeding the BCM for continuity and correct supply voltages at the module pins.
Measure power and ground at the BCM with ignition states (off, accessory, run, crank). Repair wiring as required.
Check CAN/LIN bus wiring for shorts/opens and measure CAN High/Low voltages; isolate bus segments if necessary.
If communications are intermittent, disconnect aftermarket devices and re-test; perform wiggle tests on harness while monitoring for fault change.
If wiring and power/ground check good, verify BCM software/calibration level and perform reprogramming or update per OEM service info.
If reflash does not clear the fault and all inputs/outputs verify correctly, replace BCM and program/configure replacement per OEM procedures.
After repairs, clear codes and verify repairs by exercising affected functions and re-checking for reappearance of the B0415 code.

Likely causes

Poor ground or corroded connector pins at BCM
Ungrounded or intermittent battery/ignition supply to BCM
CAN bus open/short to battery/ground or excessive bus load
Software corruption requiring reflash or calibration
BCM water damage or physical impact
Recent body wiring repair or aftermarket alarm/remote start causing a fault

Fault status

⚠️ Status

BCM detected an internal error or loss of required communications/power. Further diagnosis required to determine if failure is due to wiring, power/ground, communication bus, software, or the module itself.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0 - 3.0 hours