Airbag control unit with part number 77960-T1G-E920-M4

What does the airbag control unit 77960-T1G-E920-M4 do?

The airbag control unit 77960-T1G-E920-M4 is the central control unit of the restraint system (SRS) for Honda. It evaluates the signals from the crash sensors and decides within milliseconds in an accident which airbags and seatbelt pretensioners are triggered.

During operation the unit checks the entire system without interruption. If it detects a fault, it shows this via the airbag warning light in the instrument cluster.

After an accident the control unit records crash data and locks itself. Only a repair lifts the lock.

Why does the control unit 77960-T1G-E920-M4 fail?

The most common cause on the 77960-T1G-E920-M4 is crash data stored after an accident, even when no airbag has triggered; a normal diagnostic tool cannot erase it. Other causes are aged components, cold solder joints, moisture and corrosion on connectors, and voltage spikes.

Such data remains in the memory until it is removed during a repair. The usual tools cannot do this.

The other causes concern the electronics themselves. Solder joints can become defective, and moisture with corrosion attacks the plug contacts. Voltage spikes, for example from a weak battery or when connecting a jump-start, put additional strain on the circuit.

How can you tell that the 77960-T1G-E920-M4 is defective?

On the 77960-T1G-E920-M4, the airbag warning light in the instrument cluster lights up permanently or intermittently, and a fault message appears in the instrument cluster. The diagnostic tool finds no connection to the control unit, and the fault memory cannot be cleared. In that case airbags and seatbelt pretensioners may possibly not trigger in an emergency.

The warning light is the clearest sign. If it stays lit permanently, a fault exists in the system that must be checked.

A missing connection to the diagnostic tool can also have other causes, such as a line or a plug. A test will bring clarity before you plan any further steps.

Which vehicles is the 77960-T1G-E920-M4 fitted in?

The 77960-T1G-E920-M4 is fitted in these vehicles: Honda CR-V 4 RM (2012-2018).

For orientation, the list of vehicles recorded for this part number follows.

• Honda CR-V 4 RM (2012-2018)

Compare the part number on the label of the removed unit with this page. This only shows whether it is the right unit. Also have the fault memory read out before you start; only this result shows whether the control unit is defective or a connector or 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-T1G-G920-M4.

How does the repair of the 77960-T1G-E920-M4 work?

First have the fault memory read out. Then disconnect the battery, remove the 77960-T1G-E920-M4, and create the repair order online. Next, pack the unit well and send it in; Airbag24 tests and repairs it before it is returned to you.

The order of the first steps serves safety: 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 repaired or replaced, the stored crash data is erased, and then a function test follows. Airbag24 allows 3–4 working days for this work, and that time covers testing, repairing and checking only.

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-T1G-E920-M4 get to Airbag24?

You send the 77960-T1G-E920-M4 to Airbag24 as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns the unit by UPS.

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