Airbag control unit with part number 89170-50L02

What does the airbag control unit 89170-50L02 do?

The airbag control unit 89170-50L02 runs the restraint system (SRS) of Lexus. It evaluates the crash sensors, determines within milliseconds in an accident whether airbags and seatbelt pretensioners are triggered, and checks the system constantly.

If the system detects a fault, it indicates this via the airbag warning light in the instrument cluster. This way the driver learns of a problem before it matters in an emergency.

After an accident the unit stores crash data and locks itself.

Why does the control unit 89170-50L02 fail?

The most common cause is crash data from an earlier accident, even if no airbag has deployed. A standard diagnostic tool cannot delete this data. Other causes are ageing components, cold solder joints, moisture or corrosion at plug connections, and voltage spikes.

The crash data is stored in the control unit itself, so a look at the vehicle does not help.

The other causes affect the electronics: components age, solder joints can go cold, and moisture attacks plug connections. Voltage spikes, for example from a weak battery or a jump start, can also harm the unit.

How can you tell that the 89170-50L02 is defective?

A defect in the control unit shows up as the airbag warning light, which stays on continuously or intermittently, as a fault message in the instrument cluster, as missing connection to the diagnostic tool, or as a fault memory that cannot be cleared.

• Airbag warning light stays on continuously or intermittently
• Fault message in the instrument cluster
• Diagnostic tool finds no connection to the control unit
• Fault memory cannot be cleared

A lit warning light is a clear sign, but not proof of a defect in the control unit itself. Plugs and wiring can cause the same signs.

In an emergency, airbags and seatbelt pretensioners may fail to deploy if there is a fault in the system. So have it checked instead of ignoring the light.

Which vehicles is the 89170-50L02 fitted in?

The control unit 89170-50L02 is fitted in the following vehicles: Lexus LS XF50 (from 2018). This overview helps narrow things down, but checking the unit itself remains essential.

The list below shows the vehicles we have on record for this part number.

• Lexus LS XF50 (from 2018)

Comparing the part number on the label of the removed unit with this page only confirms the unit, not the defect. Have the fault memory read out beforehand, because only the log 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 89170-50L02 work?

Have the fault memory read out and attach the log. Then disconnect the battery and only then remove the control unit. Send the well-packed unit with an online repair order. Airbag24 usually processes the unit within 3–4 working days.

Airbag24 checks the unit on the test bench and replaces defective components. Afterwards Airbag24 deletes stored crash data and carries out a function test, before your own unit goes back.

The sequence of steps serves safety during removal and is therefore binding.

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 89170-50L02 get to Airbag24?

The unit reaches Airbag24 by parcel, or you book a UPS collection for an extra charge. The return of your own unit after the repair goes by UPS.

The printed repair order goes into the parcel. Pack the control unit shock-proof, which lets it withstand shipping better.