B2698

Code

Generic B — Body

Body Control Module Internal Fault

Brand: Generic

Type: B — Body

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Page language: EN

Causes

Failed BCM hardware (processor, memory, internal circuits)
Corrupted or failed BCM firmware/EEPROM
Low or intermittent battery voltage or poor charging
Poor power or ground connections to the BCM
Corroded or water-damaged BCM connector or housing
Shorted or damaged wiring/harness to the BCM

Symptoms

One or more body systems inoperative or intermittent (door locks, lighting, wipers, windows, HVAC blowers)
Multiple unrelated fault codes present or reappearing after clear
Warning messages on dash related to body systems
Loss of communication with BCM reported by scan tool (CAN/LIN faults)
Unusual module behavior after battery disconnect or replacement

What to check

Retrieve all stored and pending codes from the BCM and other modules with a capable scan tool
Record freeze-frame and status data; note conditions when code set
Check battery voltage and charging system (battery at rest and cranking voltages)
Inspect BCM power and ground connections for tightness, corrosion, or damage
Visually inspect BCM housing and connectors for water damage or corrosion
Check fuses and relays feeding the BCM and related circuits

Signal parameters

Battery voltage at BCM (V)
Ignition input status (RUN/ACC)
Main ground continuity/voltage drop (mV)
CAN bus message frequency and error counters (bus errors/sec)
BCM software/firmware part number and calibration ID
EEPROM/CRC or internal error flags reported by module

Diagnostic algorithm

Connect a factory-capable or bi-directional scan tool; read and record all BCM and network codes and freeze-frame data
Clear codes and attempt to reproduce; note if B2698 returns immediately or under specific conditions
Check battery state of charge and charging system; verify battery is fully charged and terminals clean/tight
Perform voltage drop test on BCM power feed and ground; repair any excessive voltage drop
Visually inspect BCM connectors and wiring for corrosion, bent pins, water ingress, or physical damage; repair as needed
Verify CAN/LIN bus wiring continuity and resistance to termination; isolate and repair shorted or open circuits
If communication errors persist, attempt to communicate with BCM from another scan tool port or using manufacturer diagnostics to determine responsiveness
If BCM appears unresponsive or reports internal memory/firmware errors, check for available TSBs or software updates; attempt reflash/reprograming only with manufacturer procedure and correct files
If reprogramming fails or module still reports internal hardware faults after verifying power/grounds/wiring, replace the BCM and program/configure per vehicle manufacturer instructions
After repairs or module replacement, clear codes and re-test all affected systems and network communication; verify no recurrence before returning vehicle to service

Likely causes

Intermittent or low battery/charging causing BCM memory corruption
Corroded connector or water ingress at BCM causing internal faults
Failed internal EEPROM or microcontroller within the BCM
Poor main ground or fused power feed to the BCM

Fault status

⚠️ Status

Stored when the Body Control Module detects an internal hardware or software fault (EEPROM, microcontroller, or internal I/O). May cause loss of body functions or communication errors.

🔴 Repair difficulty: Hard

⏱️ Diagnostic time: 2.0-5.0 hours