B1170 airbag control unit fault

What does error code B1170 mean?

Error code B1170 indicates a serious hardware defect in the airbag control unit. Specifically, the code points to a fault in the internal non-volatile memory chip, known as the EEPROM. This defect prevents the correct reading or writing of critical system data, leading to the deactivation of the entire airbag system.

The EEPROM (Electrically Erasable Programmable Read-Only Memory) is a crucial component on the control unit’s circuit board. It permanently stores vital information such as vehicle configuration, sensor calibrations, and, in the event of a crash, also crash data.

If error B1170 occurs, it means the control unit’s microprocessor can no longer reliably access this data. The system recognizes this condition as a critical safety risk and, as a protective measure, disables the airbag functions, which is indicated by the warning light.

How do you recognize error B1170?

The primary and unmistakable symptom of error B1170 is a continuously illuminated airbag warning light (SRS light) in the instrument cluster. Additionally, while the diagnostic tool can read the error code, it cannot clear it, as this is a permanent hardware defect requiring physical repair.

The airbag warning light fails to turn off after starting the vehicle or suddenly illuminates during driving. This is the system’s direct signal to the driver that a malfunction has occurred and the occupant protection systems are not operational.

In the workshop, the suspicion is confirmed when attempts to clear the fault memory fail. Code B1170 immediately reappears, as the control unit’s self-diagnosis detects the defective memory chip again with every system start-up.

What causes B1170?

The main cause of error code B1170 is physical damage to the EEPROM memory chip. This can result from mechanical impacts such as severe vibrations or an accident, electronic overloads like short circuits or voltage surges, or simply from aging and material fatigue of the component itself.

Mechanical damage is a common cause. A collision in an accident may be enough to damage the delicate solder joints or the internal structure of the memory chip, thereby triggering the error.

Another source of errors lies in electrical disturbances within the vehicle’s electrical system. Voltage spikes—caused, for example, by a faulty alternator or jump-starting with incorrect polarity—can permanently damage the sensitive EEPROM chip, rendering it unusable.

Aging processes also play a role. Like any electronic component, the EEPROM has a limited lifespan. After many years and countless read/write cycles, material fatigue may occur, leading to data corruption and error B1170.

Which vehicles are affected by B1170?

Error code B1170 appears in a specific selection of vehicle models from various manufacturers whose airbag control units use a vulnerable EEPROM architecture. Affected models include those from Audi, Skoda, Chrysler, Toyota, and Nissan, manufactured during certain model years.

At Airbag24, we repair error code B1170 for the following vehicles, among others:

Audi: A4 8W

Chrysler & Dodge: Sebring Convertible JS (2006–2010), Challenger LC

Kia & Nissan: Picanto SA/BA (2004–2011), Primera P12 (2002–2007)

Peugeot & Smart: 405 I, Forfour Edition

Skoda: Citigo 1 (2011–2020), Roomster Scout Mk1, Octavia Tour Combi Mk1

Subaru: Impreza Sedan, Legacy Touring Wagon

Toyota: Harrier XU60 (2013–2020), Vellfire Executive Lounge

How is error B1170 professionally repaired?

Professional repair of error B1170 involves component-level work. It includes removing the control unit, physically replacing the defective EEPROM chip on the circuit board, transferring the vehicle-specific configuration data to the new chip, and performing a final functional test.

After removal and shipment of the airbag control unit, Airbag24 first conducts an incoming inspection to verify error B1170. The housing is then carefully opened to gain access to the circuit board.

The core of the repair consists of precisely desoldering the defective EEPROM chip from the board. A new, high-quality chip is subsequently soldered in place. This step requires specialized equipment and extensive experience working with microelectronics.

In the next phase, the original vehicle-specific data—including chassis number, coding, and configurations—is transferred to the new EEPROM. This process ensures that, once installed, the repaired control unit communicates perfectly with the vehicle again.

After a final software reset and a comprehensive functional test, the control unit is resealed. We naturally provide 2 years’ statutory liability for defects on the repair performed.