B2794

Code

Generic B — Body

Body Control Module Configuration Error

Brand: Generic

Type: B — Body

Views: UK: 11 EN: 11 RU: 8

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

BCM programming/coding mismatch with vehicle VIN or build configuration
Incomplete or failed software update or reflash
Incorrect replacement BCM (wrong part number or region code)
Corrupted module memory or lost calibration data
Vehicle battery voltage low or power interruption during programming
CAN/bus communication faults or wiring/connectors open/shorted

Symptoms

Multiple body functions (lights, locks, windows, wipers) inoperative or behaving incorrectly
Loss of communication with BCM on diagnostic scanner
Security/immobilizer or keyless entry faults; vehicle may not start
Dashboard warning lamps related to body functions or communications
Intermittent or persistent DTCs related to other modules (communication errors)

What to check

Read all stored DTCs and freeze-frame data with a capable scan tool; note related communication codes
Verify vehicle battery voltage (should be within manufacturer specified range) and charging system
Inspect BCM power and ground fuses, fusible links, and ground points for continuity and corrosion
Visually inspect BCM connectors and CAN-bus wiring for damage, corrosion, or loose pins
Confirm BCM hardware part number, software/calibration ID, and coding values against vehicle build data or dealer database
Check for Technical Service Bulletins (TSBs) or software updates affecting BCM coding for this VIN

Signal parameters

BCM supply voltage (battery voltage at module pins)
CAN bus activity and error counters (RX/TX, bus-off status)
BCM hardware part number (HWID) and software/calibration ID (SW/CAL ID)
BCM coding/value fields (configuration bytes, VIN programmed to module)
Module address response time and UDS/ISO14229 service responses
Immobilizer pairing status or security seed/key exchange result

Diagnostic algorithm

Connect a diagnostic scanner and record B2794 plus any other codes; save freeze-frame and module data.
Verify battery state of charge and ensure stable supply (use a charger if needed).
Check fuses and grounds related to BCM; repair any open or corroded connections.
Inspect BCM connectors and wiring for physical damage; repair or secure as required.
Confirm BCM part numbers and software level. If the BCM is a replacement, verify it matches vehicle requirements.
Compare BCM coding/calibration and VIN programmed in the module against vehicle build data or manufacturer database.
If coding/calibration is incorrect or missing, perform manufacturer-recommended reprogramming/coding using an approved scan tool and latest software. Ensure battery voltage is maintained throughout.
Re-attempt security/immobilizer pairing if required after reprogramming (follow manufacturer procedure).
Clear codes, cycle ignition, and test all body functions and module communications. Monitor for reappearance of B2794.
If code persists after proper programming and wiring checks, consider module repair or replacement through authorized service, and document software/coding steps performed before replacement.

Likely causes

BCM was replaced but not correctly coded to the vehicle
Software calibration version differs from manufacturer expected build
Module programming was interrupted (battery went dead) leaving config incomplete
Connector corrosion or damaged CAN wiring preventing BCM from reading vehicle configuration
Mismatched immobilizer or VIN data between BCM and other modules

Fault status

⚠️ Status

BCM configuration error — the module reports missing or invalid configuration/coding (mismatched VIN, calibration or software). Code set when BCM configuration does not match expected vehicle data or programming has failed/interrupted.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1-4 hours