Airbag control unit with part number 77960-TBA-A05

What is the function of the airbag control unit 77960-TBA-A05?

The airbag control unit with part number 77960-TBA-A05 is the central control module for the Supplemental Restraint System (SRS) in the 10th-generation Honda Civic (FC/FK, model years approximately 2015–2022). It processes sensor data to precisely deploy airbags and seatbelt pretensioners in the event of a crash, ensuring occupant safety.

As an original Honda OEM part—also referred to as the SRS Unit, Diagnostic Module, or SDM Module—this control unit is responsible for monitoring and managing all safety‑related restraint systems. It continuously collects data from acceleration and G‑sensors to detect an impending collision.

In an emergency, the unit sends ignition signals to the corresponding airbag modules and pyrotechnic seatbelt pretensioners. At the same time, it logs all system‑relevant events and faults, which can later be read out via an interface for diagnostic purposes.

Why does the control unit 77960-TBA-A05 fail?

The most common causes of failure for the 77960-TBA-A05 control unit are internal electronic malfunctions and the storage of crash data. Often, these issues occur even without an actual accident, disabling the module’s functionality and resulting in a permanently illuminated airbag warning light.

A primary defect involves the circuit board itself. Faulty components such as capacitors or other electronic parts can disrupt operation. Additionally, moisture ingress or damage caused by improper repair attempts frequently lead to total failure or communication problems.

Another common issue is the permanent storage of crash data in the internal memory. Even after minor incidents or purely electronic faults, the control unit may enter a locked state, seemingly requiring reprogramming or replacement. However, professional repair can reliably erase this stored data.

It’s important to note that part number 77960-TBA-A05 has been replaced by the successor part number 77960-TBA-A06. This newer version remains compatible with earlier variants 77960-TBA-A01, A02, A03, and A04.

How do you recognize a fault in the 77960-TBA-A05?

A defective airbag control unit 77960-TBA-A05 typically manifests as a persistently illuminated airbag warning light on the instrument panel. Additionally, complete loss of communication with diagnostic tools may occur, rendering the fault memory unreadable.

The most obvious symptom is the airbag warning lamp that fails to turn off after starting the vehicle. This indicates a critical error in the SRS system, posing a risk to occupant safety.

In the workshop, the fault often becomes apparent when the control unit no longer responds via the OBD interface. Diagnostic equipment receives no response, or stored fault codes cannot be cleared—even after replacing other components like the coil spring.

Other accompanying symptoms may include sporadic or persistent failures of other electronic components. Reports mention clock malfunctions, flashing engine check lights, or complete control unit failure under thermal stress, such as during hot weather.

In which vehicles is the 77960-TBA-A05 installed?

The airbag control unit 77960-TBA-A05 is specifically designed for the tenth generation of the Honda Civic. It appears across various body styles and trim levels of the FC and FK series produced between 2015 and 2022.

At Airbag24, we repair the 77960-TBA-A05 control unit for the following models:

Honda Civic 10th Generation (FC/FK series, model years approximately 2015–2022). This includes variants such as the 5-door EX, LX, and Sport trims from model years 2016 to 2021, equipped with either KA 6MT or KA CVT transmissions.

Is repairing the 77960-TBA-A05 worthwhile?

Yes, repair represents an economically and technically sensible alternative to costly new purchases. Not only do you save significantly—up to €800—but you also receive a plug-and-play solution that requires no complex reprogramming or coding within the vehicle.

According to the manufacturer, a new control unit often costs over €500. Repair is considerably cheaper and restores full functionality of the original component. This not only protects your budget but also helps preserve the environment by reusing existing parts.

Following professional refurbishment, the control unit is immediately ready for use. There’s no need for re‑learning or re‑coding at an authorized dealer. Installation is straightforward, and the airbag warning light should extinguish once any residual errors have been cleared from the vehicle. Furthermore, we back our work with 2 years’ statutory liability for defects.

How does the repair of the 77960-TBA-A05 proceed?

Repair at Airbag24 is a straightforward process. After removal, you send us the defective control unit. Our technicians perform a precise electronic analysis, fix the fault at the component level, and erase stored crash data. The unit is then tested and returned ready for installation.

First, the defective control unit should be professionally removed from the vehicle. Pack it securely for transport and ideally include a detailed description of the fault, along with a diagnostic report if available. This will speed up the analysis.

Upon receipt at Airbag24, the unit undergoes a comprehensive inspection. Our technicians identify the root cause of the issue—whether it’s a faulty component, memory error, or locked crash data. Repairs are carried out directly on the circuit board, including replacing defective parts and restoring the original software configuration.

Subsequently, the repaired control unit undergoes a functional test to ensure flawless operation. The repair is performed without requiring reprogramming in the vehicle. We provide 2 years' statutory liability for defects on all our repairs.