Airbag control unit with part number 77960-TLA-C320-M4

What does the airbag control unit 77960-TLA-C320-M4 do?

The airbag control unit 77960-TLA-C320-M4 is the central control unit of the restraint system (SRS) for Honda. It evaluates the signals from the crash sensors and decides in an accident, within milliseconds, which airbags and seatbelt pretensioners are triggered.

Outside an accident the unit monitors the system continuously. If it detects a fault, it reports it via the airbag warning light in the instrument cluster.

After an accident the control unit stores crash data and then locks itself. This behaviour is part of the safety logic of the restraint system.

Why does the control unit 77960-TLA-C320-M4 fail?

The most common cause for the 77960-TLA-C320-M4 is crash data stored after an accident, even if no airbag has deployed. A normal diagnostic tool cannot erase it. Aged electronic components, cold solder joints, moisture and corrosion on plug connectors, and voltage spikes are further possible causes.

The crash data stays in the memory until it is specifically removed. This is why an accident can still have an effect even when the vehicle continues to drive normally.

The other causes act over years. Electronics age, solder joints can go cold, and moisture attacks the contacts. Voltage spikes arise, for example, from a weak battery or a jump start.

How can you tell that the 77960-TLA-C320-M4 is defective?

A defect in the 77960-TLA-C320-M4 shows itself through an airbag warning light that stays lit or lights up intermittently in the instrument cluster. In addition there are fault messages, a missing connection to the diagnostic tool, and a fault memory that cannot be cleared.

The airbag warning light in the instrument cluster stays on permanently or switches on again and again. A fault message also appears in the instrument cluster, and the diagnostic tool finds no connection to the control unit.

If the fault memory remains after an attempt to clear it, that is a further sign of a fault. In this state airbags and seatbelt pretensioners may not deploy in an emergency, even if the vehicle behaves inconspicuously in everyday use.

Which vehicles is the 77960-TLA-C320-M4 fitted in?

The control unit 77960-TLA-C320-M4 is fitted in these vehicles: Honda CR-V 5 (2018-2023). The part number on the label of the removed unit can be compared with this page.

The following list shows the vehicles stored for this control unit.

• Honda CR-V 5 (2018-2023)

Two steps will help you. Comparing the label with this page only ensures that you have the correct unit in front of you. Before that, have the fault memory read out: only this result shows whether the control unit is defective or whether 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-C320-M4 work?

First have the fault memory read out, attach the log and only then disconnect the battery. Then remove the control unit 77960-TLA-C320-M4, create a repair order online and send the unit in. Processing at Airbag24 usually takes 3–4 working days.

The order is fixed for safety reasons. The control unit is only removed once the battery has been disconnected.

At Airbag24 the unit is examined on the test bench, defective components are replaced and stored crash data is erased. A function test then follows, after which your own unit goes back to you. 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-C320-M4 get to Airbag24?

You send the control unit 77960-TLA-C320-M4 as a parcel or book a UPS collection for an extra charge. After the repair Airbag24 sends the unit back by UPS.

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