Airbag control unit with part number 89170-42C91

What does the airbag control unit 89170-42C91 do?

For Toyota, the airbag control unit 89170-42C91 processes the signals from the crash sensors and, in an accident, selects the airbags and seatbelt pretensioners that fire. It also monitors the restraint system continuously.

The airbag warning light in the instrument cluster displays detected faults. The control unit works without interruption throughout.

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

Why does the control unit 89170-42C91 fail?

Stored crash data from an accident is the most common cause, even when no airbag has fired. A normal diagnostic tool leaves it in place. Other causes include ageing components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

Airbag24 erases the crash data during the repair. Until then, these records cannot be removed by conventional means.

The other causes concern the electronics inside the unit: components age, solder joints may have gone cold, and wetness or corrosion damages contacts. Voltage spikes arise, for example, when the battery is weak or a jump start is connected.

How can you tell that the 89170-42C91 is defective?

A fault in the 89170-42C91 is indicated by an airbag warning light in the instrument cluster that stays on permanently or intermittently. An error message in the instrument cluster, a missing connection to the diagnostic tool or a fault memory that cannot be cleared also point to a fault.

The signs at a glance:

• Airbag warning light on permanently or intermittently
• Error message in the instrument cluster
• Diagnostic tool cannot reach the control unit
• Fault memory cannot be cleared

In an emergency, airbags and seatbelt pretensioners may then possibly not deploy. Please arrange a check promptly.

Which vehicles is the 89170-42C91 fitted in?

The 89170-42C91 is used in these vehicles: Toyota RAV4 XA50 (from 2018).

The affected models for which the part number is recorded are listed here:

• Toyota RAV4 XA50 (from 2018)

Use this page to compare the part number on the label; this only confirms the assignment of the unit. The cause is revealed only by a fault memory read out beforehand, which shows whether the control unit is faulty or whether a plug or cable is affected.

For the same vehicles, we also repair control units with the part numbers 150800-4431, 152100-0262, 152100-4560, 89170-42400, 89170-42870, 89170-42A60.

How does the repair of the 89170-42C91 work?

Airbag24 needs 3–4 working days for testing, repairing and checking. First read out the fault memory and enclose the log, then disconnect the battery; only then remove the control unit. Afterwards, create the repair order online and send the unit in, well packed.

At Airbag24, the unit is examined on the test bench. Defective components are replaced, the stored crash data is erased and a function test is carried out, after which the unit is returned.

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 89170-42C91 get to Airbag24?

The 89170-42C91 reaches Airbag24 as a parcel, or you book a UPS collection for an extra charge. The return after the repair takes place by UPS.

A printed repair order goes into the carton, and the unit must be packed shock-resistant.