Code
B1656
HUMMER
B — Body
EEPROM Write Error
Views:
UK: 15
EN: 22
RU: 18
AI status
Completed
Completed
100%
Causes
- Interrupted write cycle due to low or unstable battery voltage (power loss during programming).
- Corroded, loose, or damaged power/ground/connectors to the affected module.
- Internal EEPROM memory corruption or failed memory cells within the module.
- Failed or marginal module electronics (processor, memory controller, solder joints).
- Software/firmware bug or incomplete/failed module reprogramming update.
- Aftermarket equipment installation or modifications that write to module memory.
Symptoms
- DTC B1656 stored in module memory and possibly MIL or SIR/airbag light depending on module.
- Loss of stored options or calibrations (seat memory, comfort settings, airbag data).
- Intermittent or permanent loss of module functions controlled by the module.
- Communication errors with the module on CAN/LIN bus.
- Module may not accept programming or fail verification during reflash.
What to check
- Read all stored DTCs and freeze frame data with a capable scan tool; note related codes and events.
- Check battery voltage and charging system (resting voltage and cranking voltage).
- Inspect module connectors, pins, and grounds for corrosion, bent pins, or poor contact.
- Check for signs of water intrusion or physical damage to the module.
- Verify vehicle software/flash history; check for recent reprogramming attempts or aftermarket installations.
- Attempt to clear the code and see if it returns immediately or after a specific operation (e.g., reprogramming, key cycle).
Signal parameters
- VBATT (battery voltage) at module (should be ~12.4–12.8V resting; >11V during cranking).
- Module ground resistance/continuity to chassis ground.
- CAN/LIN bus activity and voltage levels.
- Module internal status flags (EEPROM write/verify errors, checksum failures) from scan tool.
- Module firmware/software part number and program status.
- Freeze frame timestamp and ignition cycle count when code set.
Diagnostic algorithm
- Use a factory-level or manufacturer-capable scan tool and read all DTCs and module data. Save freeze frame and event history.
- Verify battery state-of-charge and charging system. Charge or replace battery if voltage is low; ensure stable Vbatt during tests.
- Visually inspect and verify tightness/condition of module power and ground connections. Clean and secure connectors and terminals.
- Check vehicle network (CAN/LIN) communication: verify proper bus voltages and no shorting or high resistance wiring. Repair wiring as needed.
- Clear the code and perform operation that previously set it (or cycle ignition). If code returns immediately, proceed.
- If vehicle had a recent programming/update, verify the programming process completed successfully; attempt to reprogram module with latest OEM calibration using manufacturer tools and follow TSB instructions. Ensure battery is fully charged and using recommended power supply during reflash.
- If reprogram/reflash fails or EEPROM errors persist, consider module replacement. If available, compare with known-good module or send module to authorized bench programmer/repair service for EEPROM repair.
- After repair or replacement, reprogram and relearn any vehicle-specific calibrations and clear codes. Verify system operation and absence of recurrence over several key cycles.
Likely causes
- Faulty module EEPROM or internal electronics.
- Low battery voltage or poor battery/charging system condition during a write attempt.
- Loose or corroded power/ground/connector at the module.
- Failed or interrupted module reflash/update (incomplete programming).
Fault status
Status
The module experienced a failed write or verification operation to its internal EEPROM (non-volatile memory). This indicates memory corruption or inability to complete programming/writing; could be caused by power loss, wiring issues, or internal module failure.
Repair difficulty: Hard
Diagnostic time: 1.0-3.0 hours
Similar codes
Repair manuals
Manual library for HUMMER
69
Browse 69 HUMMER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.
HUMMER
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Code
B1656
Other
B — Body
Seat Driver Rear Up Circuit Open
Views:
UK: 22
EN: 29
RU: 22
AI status
Completed
Completed
100%
Causes
- Interrupted write cycle due to low or unstable battery voltage (power loss during programming).
- Corroded, loose, or damaged power/ground/connectors to the affected module.
- Internal EEPROM memory corruption or failed memory cells within the module.
- Failed or marginal module electronics (processor, memory controller, solder joints).
- Software/firmware bug or incomplete/failed module reprogramming update.
- Aftermarket equipment installation or modifications that write to module memory.
Symptoms
- DTC B1656 stored in module memory and possibly MIL or SIR/airbag light depending on module.
- Loss of stored options or calibrations (seat memory, comfort settings, airbag data).
- Intermittent or permanent loss of module functions controlled by the module.
- Communication errors with the module on CAN/LIN bus.
- Module may not accept programming or fail verification during reflash.
What to check
- Read all stored DTCs and freeze frame data with a capable scan tool; note related codes and events.
- Check battery voltage and charging system (resting voltage and cranking voltage).
- Inspect module connectors, pins, and grounds for corrosion, bent pins, or poor contact.
- Check for signs of water intrusion or physical damage to the module.
- Verify vehicle software/flash history; check for recent reprogramming attempts or aftermarket installations.
- Attempt to clear the code and see if it returns immediately or after a specific operation (e.g., reprogramming, key cycle).
Signal parameters
- VBATT (battery voltage) at module (should be ~12.4–12.8V resting; >11V during cranking).
- Module ground resistance/continuity to chassis ground.
- CAN/LIN bus activity and voltage levels.
- Module internal status flags (EEPROM write/verify errors, checksum failures) from scan tool.
- Module firmware/software part number and program status.
- Freeze frame timestamp and ignition cycle count when code set.
Diagnostic algorithm
- Use a factory-level or manufacturer-capable scan tool and read all DTCs and module data. Save freeze frame and event history.
- Verify battery state-of-charge and charging system. Charge or replace battery if voltage is low; ensure stable Vbatt during tests.
- Visually inspect and verify tightness/condition of module power and ground connections. Clean and secure connectors and terminals.
- Check vehicle network (CAN/LIN) communication: verify proper bus voltages and no shorting or high resistance wiring. Repair wiring as needed.
- Clear the code and perform operation that previously set it (or cycle ignition). If code returns immediately, proceed.
- If vehicle had a recent programming/update, verify the programming process completed successfully; attempt to reprogram module with latest OEM calibration using manufacturer tools and follow TSB instructions. Ensure battery is fully charged and using recommended power supply during reflash.
- If reprogram/reflash fails or EEPROM errors persist, consider module replacement. If available, compare with known-good module or send module to authorized bench programmer/repair service for EEPROM repair.
- After repair or replacement, reprogram and relearn any vehicle-specific calibrations and clear codes. Verify system operation and absence of recurrence over several key cycles.
Likely causes
- Faulty module EEPROM or internal electronics.
- Low battery voltage or poor battery/charging system condition during a write attempt.
- Loose or corroded power/ground/connector at the module.
- Failed or interrupted module reflash/update (incomplete programming).
Fault status
Status
The module experienced a failed write or verification operation to its internal EEPROM (non-volatile memory). This indicates memory corruption or inability to complete programming/writing; could be caused by power loss, wiring issues, or internal module failure.
Repair difficulty: Hard
Diagnostic time: 1.0-3.0 hours
Similar codes
Repair manuals
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3,330
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