BCM NVM Failure Code B2143
Diagnostic trouble code B2143 indicates a non-volatile memory (NVM) fault within a control module, most commonly the Body Control Module (BCM) or Sensing and Diagnostic Module (SDM) on General Motors vehicles. This code is set when the module detects a checksum error, data corruption, or an inability to read or write to its internal EEPROM, which stores vehicle configuration, calibrations, and security codes.
1. Commonly Affected Makes
2. Most Common Causes
- Internal hardware failure of the control module (BCM/SDM) due to EEPROM degradation
- Power interruption (low battery or disconnection) during a reprogramming or memory write event
- Damage from overvoltage or voltage spikes on the module's power or data bus
- Corrosion or poor connection at the module connectors causing communication errors during memory verification
- Failed key programming or option configuration attempts using a diagnostic tool (J2534)
3. Symptoms You Will Notice
- Check Engine Light or Service Vehicle Soon light illuminated
- Malfunctioning body electrical features (windows, locks, lights) or airbag warning light
4. Step-by-Step Diagnosis
Verify battery voltage is stable and above 12.6 volts; charge or replace if low
Inspect module connectors for corrosion, bent pins, or poor seating; clean and tighten as needed
Attempt to reprogram the module with factory-level scan tool; if unsuccessful, replace the module
Check for related DTCs and perform a complete system scan to identify other affected modules
5. Frequently Asked Questions
Is it safe to drive?▼
Driving is not recommended as the fault may cause unpredictable electrical failures or disable safety systems like airbags.
How much does it cost to fix?▼
Repair costs typically range from $200 to $800, including diagnosis, module replacement, and programming.