Airbag control unit with part number 77960-T0N-M720-M4

What does the airbag control unit 77960-T0N-M720-M4 do?

The airbag control unit 77960-T0N-M720-M4 is the central control unit of the SRS system in Honda. It processes the readings from the crash sensors and decides within milliseconds in an accident which airbags and seatbelt pretensioners fire. If it detects a fault, it reports it via the airbag warning light.

As soon as the ignition is on, monitoring runs in the background. The connections to the triggers are checked as well, so the system is monitored continuously and not only in an accident.

After an accident the unit records crash data and then locks itself. The lock is only lifted by the repair.

Why does the control unit 77960-T0N-M720-M4 fail?

The most common cause on the 77960-T0N-M720-M4 lies in crash data stored after an accident, even if no airbag has deployed. Other causes include aged electronic components, cold solder joints, moisture and corrosion at connectors, and voltage spikes (for example with a weak battery or a jump start).

Crash data cannot be erased with a normal diagnostic tool. Airbag24 erases it during the repair.

Aged components and cold solder joints cause faults that are hard to see from outside. A look at the connectors is therefore not enough, because moisture and corrosion cannot be reliably seen there.

Voltage spikes occur, for example, when the battery is weak or a vehicle is started with an external power source. Such loads strain the electronics and can damage components.

How can you tell that the 77960-T0N-M720-M4 is defective?

A defect on the 77960-T0N-M720-M4 shows up as the airbag warning light, which lights up permanently or intermittently, as an error message in the instrument cluster, or because a diagnostic tool cannot establish a connection. A fault memory that cannot be cleared also indicates this.

• Airbag warning light lights up permanently or intermittently
• Error message in the instrument cluster
• Diagnostic tool receives no connection to the control unit
• Fault memory cannot be cleared

In an emergency, airbags and seatbelt pretensioners may then fail to deploy. The warning light therefore makes the defect visible, and a prompt check is advisable.

Which vehicles is the 77960-T0N-M720-M4 fitted in?

A comparison with your own vehicle shows whether the unit fits. The control unit 77960-T0N-M720-M4 is fitted in these vehicles: Honda CR-V 4 RM (2012-2018).

The vehicles to which we assign this unit are listed here:

• Honda CR-V 4 RM (2012-2018)

On the one hand, compare the part number on the label of the removed unit with this page. This only confirms that it is the right unit. On the other hand, have the fault memory read out in advance, because only this record shows whether the control unit itself is defective or whether a connector or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 77960-T0A-3070-M4, 77960-T0A-A012-M1, 77960-T0A-A013-M1, 77960-T0A-A210-M1, 77960-T0A-A212-M1, 77960-T0A-A230-M1.

How does the repair of the 77960-T0N-M720-M4 work?

First have the fault memory read out and enclose the log, then disconnect the battery and remove the control unit. Then create a repair order online and send in the unit well packed. At Airbag24, processing of the 77960-T0N-M720-M4 usually takes 3–4 working days.

Airbag24 examines the unit on the test bench and repairs defective components. Stored crash data is then erased, and a function test checks the system. The unit then 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-T0N-M720-M4 get to Airbag24?

The 77960-T0N-M720-M4 goes to Airbag24 either as a parcel or with a UPS collection that you book for an extra charge. After the repair, Airbag24 sends it back by UPS.

Enclose the printed repair order in the parcel. Pack the unit shock-proof so that it survives transport undamaged.