Airbag control unit with part number 77960-TLA-A410-M4

What does the airbag control unit 77960-TLA-A410-M4 do?

The airbag control unit 77960-TLA-A410-M4 is the central control unit of the restraint system (SRS) in Honda. It evaluates the signals from the crash sensors, decides in the event of an emergency within fractions of a second which airbags and seatbelt pretensioners are triggered, and reports faults via the airbag warning light.

The control unit works in the background and continuously checks its connections as well as the connected sensors. This way a fault is noticed as soon as it occurs and is recorded in the fault memory. The display in the instrument cluster is therefore the system's direct feedback to the driver.

After an accident the unit stores crash data and locks itself. For the workshop, this is the starting point of every fault search on the restraint system, because without a readout it remains unclear which events the unit has already recorded.

Why does the control unit 77960-TLA-A410-M4 fail?

The most common cause is crash data stored after an accident, even if no airbag was triggered; a normal diagnostic tool cannot erase it. Aged electronic components, cold solder joints, moisture and corrosion at plug connectors, and voltage spikes such as those from a weak battery or a jump start are further possible causes.

The fact that no airbag was triggered does not mean that no crash data was stored. These entries remain in the unit until they are erased during a repair, and they cannot be seen from outside on the vehicle.

The other causes concern ageing and contacts inside the unit as well as the power supply. They can hardly be narrowed down without reading the fault memory, because a plug and the unit itself can show similar symptoms.

How can you tell that the 77960-TLA-A410-M4 is defective?

If the airbag warning light in the instrument cluster stays on permanently or intermittently, this is a warning sign. An error message in the instrument cluster likewise indicates a defect, as does a diagnostic tool that cannot connect to the control unit, or a fault memory that cannot be cleared. In an emergency, airbags and seatbelt pretensioners may then fail to trigger.

The warning light is not a cosmetic fault that can be ignored. It makes the fault visible as soon as it occurs and calls for a check of the system.

Whether the control unit itself is affected or a plug is behind the fault only shows when the fault memory is read out. A glance at the unit or the instrument cluster is not enough for that.

Which vehicles is the 77960-TLA-A410-M4 fitted in?

A 77960-TLA-A410-M4 control unit belongs to Honda. It is fitted in these vehicles: Honda CR-V 5 (2018-2023).

The following overview shows the assigned vehicles:

• Honda CR-V 5 (2018-2023)

Compare the part number on the label of the removed unit with this page. This only ensures that you have the right unit. In addition, have the fault memory read out, because only this protocol shows whether the control unit is defective or a plug or a cable is the cause.

For the same vehicles, we also repair control units with the part numbers 5WK43782, 77960-SWA-G212-M4, 77960-SWA-G214-M4, 77960-SWAA-213-M1.

How does the repair of the 77960-TLA-A410-M4 work?

First have the fault memory read out and enclose the protocol. Then disconnect the battery, and only after that remove the control unit. Next, create a repair order online and pack the unit well before sending it in.

Airbag24 checks the unit on the test bench, repairs defective components, erases stored crash data and carries out a function test. Afterwards the unit goes back to you.

Processing at Airbag24 usually takes 3–4 working days. This time applies only to checking, repairing and testing at Airbag24.

Our repairs come with 2 years' statutory liability for defects. The repaired control unit comes back with all vehicle data and is ready for use as soon as it is refitted — no coding or programming is required.

How does the control unit 77960-TLA-A410-M4 get to Airbag24?

You send the unit as a parcel, or you book a UPS collection for an extra charge. After the repair, Airbag24 returns it to you by UPS.

Put the printed repair order into the parcel and pack the unit shock-proof.