Airbag control unit with part number 89170-50M50

What does the airbag control unit 89170-50M50 do?

The airbag control unit 89170-50M50 is the central control unit of the restraint system (SRS) in the Lexus. It evaluates the signals from the crash sensors and decides in an accident, within milliseconds, which airbags and seatbelt pretensioners are triggered. Detected faults are indicated via the airbag warning light.

After an accident, the unit stores crash data and locks itself. In everyday use, the electronics run unnoticed in the background and continuously check sensors, wiring and trigger circuits.

Why does the control unit 89170-50M50 fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed; a normal diagnostic tool cannot delete it. Other causes include ageing electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes.

Stored crash data remains in the unit until it is deleted. Airbag24 deletes it during the repair.

Whether a plug or a cable is affected does not show itself. Voltage spikes arise, for example, from a weak battery or when jump-start cables are connected.

How can you tell that the 89170-50M50 is defective?

Typical signs are an airbag warning light in the instrument cluster that lights up permanently or intermittently, and a fault message in the instrument cluster. In an emergency, airbags and seatbelt pretensioners may then fail to deploy.

• airbag warning light in the instrument cluster lights up permanently or intermittently
• fault message in the instrument cluster
• diagnostic tool cannot establish a connection to the control unit
• fault memory cannot be cleared

If the warning light is on, have the system checked promptly.

Which vehicles is the 89170-50M50 fitted in?

The control unit 89170-50M50 is fitted in these vehicles: Lexus LS XF50 (from 2018).

The list shows the vehicles that belong to this part number.

• Lexus LS XF50 (from 2018)

Compare the part number on the label of the removed unit with this page; this only ensures that it is the right unit. Also have the fault memory read beforehand, because only that shows whether the control unit is defective or whether a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers 89170-50K81, 89170-50K83, 89170-50L00, 89170-50L03, 89170-53790, 89170-53820.

How does the repair of the 89170-50M50 work?

First have the fault memory read and the log enclosed. Then disconnect the battery before removing the control unit. Afterwards, create a repair order online and send in the well-packed unit.

Airbag24 examines the unit on the test bench, replaces defective components, deletes stored crash data and carries out a function test. After that, your own unit is returned to you.

Processing at Airbag24 usually takes 3–4 working days. 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 89170-50M50 get to Airbag24?

You send the control unit as a parcel or 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.